How to maintain session using HttpWebRequest and SetCookies?

[Peter Qian]

Hi,
I'm working on a windows form based program that can log into a web
service (Apache based, https is used for auth). I was able to post the login
data and obtain a sessionID. However I'm not sure how to maintain this id
over multiple requests. Here are my code:


Globle Varibles
private static int timeOut = 20000;
private CookieContainer cookieContainer; /* other cookies */
private string headerCookie; /* often stores session info */
private string cookieHeader;

1. Login Routine:

public bool OpenLoginSession( string url,
System.Collections.Specialized.NameValueCollection param )
{
WebHeaderCollection headers;
bool statusOK;

HttpWebRequest loginReq =
(HttpWebRequest)WebRequest.Create(url);
cookieContainer = new CookieContainer();
HttpWebResponse loginRes;
//
// Login Request
//
loginReq.CookieContainer = cookieContainer;
loginReq.KeepAlive = false;
loginReq.Method = "POST";
loginReq.AllowAutoRedirect = false;
//
// Build POST stream
//
System.Text.StringBuilder query = new StringBuilder();
query.Append("?");
foreach( string key in param.Keys )
{
query.AppendFormat("{0}={1}&", key, param[key]);
}
byte[] buf = System.Text.ASCIIEncoding.ASCII.GetBytes(
query.ToString() );
Stream os = loginReq.GetRequestStream();
os.Write( buf, 0, buf.Length );
os.Close();
//
// POST the info
//
loginRes = (HttpWebResponse)loginReq.GetResponse();
cookieHeader = cookieContainer.GetCookieHeader(
loginReq.RequestUri );


if ( loginReq.HaveResponse && loginRes.StatusCode ==
HttpStatusCode.OK )
{
headers = loginRes.Headers;
if ( headers["Set-Cookie"] != null )
{
headerCookie = headers["Set-Cookie"];
}

statusOK = true;
}
else
statusOK = false;

loginRes.Close();
return(statusOK);

}

Note, after this routine, "cookieHeader" is an empty string for some reason,
and headerCookie stores the sessionID correctly.

2. Browsing Routine

public void BrowseSecuredUrl( string url )
{
HttpWebRequest req =
(HttpWebRequest)WebRequest.Create(url);
HttpWebResponse res;

cookieContainer = new CookieContainer();
req.CookieContainer = cookieContainer;
req.KeepAlive = false;
req.Headers.Add("Cookie", headerCookie);

cookieContainer.SetCookies( req.RequestUri ,
cookieHeader );//error here

res = (HttpWebResponse)req.GetResponse();
...
res.Close();

}

The error I'm getting "is An error has occurred when parsing Cookie header
for Uri '...'"

I'm wondering what is the correct way of doing things?

Thanks!


Regards,

Peter