Develop Reference

Infinite cycle in login function (CookieCollection)

The following function is wrote in C#, and it's used for logging in to a website (using POST Method and setting up Cookies).
The problem is that if my first login with bad username or password, I cannot log in again until i run the program again. The function is executed once, and if the login information is wrong, it ends after few minutes with this error:
Stream newStream = getRequest.GetRequestStream(); // open connection
WebException was unhandled by user code:
timeout expired
I would like to ask for a little help to find out what is wrong. In my opinion, the mistake could be in the use of CookieCollection - I would like to delete all existing cookies in case of unsuccessful login, but I cannot figure it out. I'm using this solution:
private bool Login(string name, string password)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://.../login-page/");
request.CookieContainer = new CookieContainer();
request.CookieContainer.Add(cookies);
//Get the response from the server and save the cookies from the first request..
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
cookies = response.Cookies;
string sourceCode;
string getUrl = "http://.../login/";
string postData = String.Format("username={0}&password={1}", name, password);
HttpWebRequest getRequest = (HttpWebRequest)WebRequest.Create(getUrl);
getRequest.CookieContainer = new CookieContainer();
getRequest.CookieContainer.Add(cookies); //recover cookies First request
getRequest.Method = WebRequestMethods.Http.Post;
getRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2";
getRequest.AllowWriteStreamBuffering = true;
getRequest.ProtocolVersion = HttpVersion.Version11;
getRequest.AllowAutoRedirect = true;
getRequest.ContentType = "application/x-www-form-urlencoded";
byte[] byteArray = Encoding.ASCII.GetBytes(postData);
getRequest.ContentLength = byteArray.Length;
Stream newStream = getRequest.GetRequestStream(); // open connection
newStream.Write(byteArray, 0, byteArray.Length); // Send the data.
newStream.Close();
HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
cookies = getResponse.Cookies;
using (StreamReader sr = new StreamReader(getResponse.GetResponseStream()))
{
sourceCode = sr.ReadToEnd();
}
if (sourceCode.Contains("<div id='login'>Přihlášení se zdařilo</div>"))
{
return true;
}
return false;
}
Code from: https://stackoverflow.com/a/8542205/2715725
I would really appreciate any kind of help. I'm not that into C# and I have problems to put this kind of code together. I have been trying to solve this for days, but even Google haven't helped me, I was looking for the solutin everywhere Thank you!

It looks like the fault most likely lies in the external site to which you are posting the username and password. Are you sure it displays that exact message both when you authenticate correctly the first time, and when you manage to authenticate after a failed logon? Try both actions directly on that site to find out.

PROBLEM SOLVED
I added this into my function:
request.KeepAlive = false;
response.Close();
getRequest.KeepAlive = false;
getResponse.Close();

Add this to your function:
request.KeepAlive = false;
response.Close();
getRequest.KeepAlive = false;
getResponse.Close();

How to login a website using httpwebrequest via my web app or generic handler and access the content?

Basically I am making a chat app for my university students only and for that I have to make sure they are genuine by checking there details on UMS(university management system) and get their basic detail so they chat genuinely. I am nearly done with my chat app only the login is left.
So I want to login to my UMS page via my website from a generic handler.
and then navigate to another page in it to access there basic info keeping the session alive.
I did research on httpwebrequest and failed to login with my credentials.
https://ums.lpu.in/lpuums
(made in asp.net)
I did tried codes from other posts for login.
I am novice to this part so bear with me.. any help will be appreciated.

Without the actual handshake with UMS via a defined API, you would end up scraping UMS html, which is bad for various reasons.
I would suggest you read up on Single Sign On (SSO).
A few articles on SSO and ASP.NET -
1. Codeproject
2. MSDN
3. asp.net forum
Edit 1
Although, I think this is a bad idea, since you say you are out of options, here is a link that shows how Html Agility Pack can help in scraping the web pages.
Beware of the drawbacks of screen scraping, changes from UMS will not be communicated to you, and you will see your application not working all of a sudden.

public string Scrap(string Username, string Password)
{
string Url1 = "https://www.example.com";//first url
string Url2 = "https://www.example.com/login.aspx";//secret url to post request to
//first request
CookieContainer jar = new CookieContainer();
HttpWebRequest request1 = (HttpWebRequest)WebRequest.Create(Url1);
request1.CookieContainer = jar;
//Get the response from the server and save the cookies from the first request..
HttpWebResponse response1 = (HttpWebResponse)request1.GetResponse();
//second request
string postData = "***viewstate here***";//VIEWSTATE
HttpWebRequest request2 = (HttpWebRequest)WebRequest.Create(Url2);
request2.CookieContainer = jar;
request2.KeepAlive = true;
request2.Referer = Url2;
request2.Method = WebRequestMethods.Http.Post;
request2.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
request2.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2";
request2.ContentType = "application/x-www-form-urlencoded";
request2.AllowWriteStreamBuffering = true;
request2.ProtocolVersion = HttpVersion.Version11;
request2.AllowAutoRedirect = true;
byte[] byteArray = Encoding.ASCII.GetBytes(postData);
request2.ContentLength = byteArray.Length;
Stream newStream = request2.GetRequestStream(); //open connection
newStream.Write(byteArray, 0, byteArray.Length); // Send the data.
newStream.Close();
HttpWebResponse response2 = (HttpWebResponse)request2.GetResponse();
using (StreamReader sr = new StreamReader(response2.GetResponseStream()))
{
responseData = sr.ReadToEnd();
}
return responseData;
}
This is the code which works for me any one can add there links and viewstate for asp.net websites to scrap and you need to take care of cookie too.
and for other websites(non asp.net) they don't require viewstate.
Use fiddler to find things needed to add in header and viewstate or cookie.
Hope this helps if some one having the problem. :)

HttpWebRequest (post) and redirection

I'm trying to log onto the following website using HttpWebRequest: http://mostanmeldung.moessinger.at/login.php
Texts are in German, but they don't really matter. If you look at the source code (which by the way was not written by me, so don't blame me for its bad style :P), you will see a form tag that contains two input tags. The name of the first one is "BN" (username), and the name of the second one is "PW" (password). I am trying to send data containing values for these two inputs to the webserver using the HttpWebRequest class. However, posting the values redirects the request to another page called "einloggen.php". On that site I am told whether my login was successful.
My problem is that I am able to send the data without any problems, however, all I receive is the content of "login.php", the site you have to enter your username and password on.
This is what my code looks like:
string post = String.Format(PostPattern, Username, Password);
byte[] postBytes = Encoding.ASCII.GetBytes(post);
CookieContainer cookies = new CookieContainer();
// "Address": http://mostanmeldung.moessinger.at/login.php
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(Address);
req.CookieContainer = cookies;
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = postBytes.Length;
req.AllowAutoRedirect = true;
MessageBox.Show(post); // shows me "BN=boop;PW=hi"
Stream reqStream = req.GetRequestStream();
reqStream.Write(postBytes, 0, postBytes.Length);
reqStream.Close();
WebResponse res;
if (/*req.HaveResponse &&*/ (res = req.GetResponse()) != null)
{
StreamReader reader = new StreamReader(res.GetResponseStream());
MessageBox.Show(reader.ReadToEnd());
return AuthResult.Success;
}
return AuthResult.NoResponse;
The message box at line 22 (5 lines before the end) shows me the content of "login.php" instead of "einloggen.php" which I am redirected to. Why is that?

The ACTION on that form points to einloggen.php, not login.php, so you need to send your POST data to einloggen.php instead.

HttpWebRequest, c# and Https

I have tried many ways to login to an https website programmatically, but I am having issues. Every time I get an error stating that my login and password are incorrect. I am sure they are correct because I can login to the site via the browser using the same credentials.
Failing Code
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://www.majesticseo.com/account/login?EmailAddress=myemail&Password=mypass&RememberMe=1");
request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,**;q=0.8";
request.UnsafeAuthenticatedConnectionSharing = true;
request.Method = "POST";
request.KeepAlive = true;
request.ContentType = "application/x-www-form-urlencoded";
request.AllowAutoRedirect = true;
request.CookieContainer = container;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
//String tmp;
foreach(Cookie cookie1 in response.Cookies)
{
container.Add(cookie1);
}
Stream stream = response.GetResponseStream();
string html = new StreamReader(stream).ReadToEnd();
Console.WriteLine("" + html);

That site uses HTTP POST for login, and does not send the username and password in the URL.
The correct login URL is https://www.majesticseo.com/account/login
You need to create a string of data to post, convert it to a byte array, set the content length and then do your request. It is very important that the content-length is sent. Without it the post will not work.
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://www.majesticseo.com/account/login?EmailAddress=myemail&Password=mypass&RememberMe=1");
request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0";
request.Referer = "https://www.majesticseo.com/account/login";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,**;q=0.8";
request.UnsafeAuthenticatedConnectionSharing = true;
request.Method = "POST";
request.KeepAlive = true;
request.ContentType = "application/x-www-form-urlencoded";
request.AllowAutoRedirect = true;
// the post string for login form
string postData = "redirect=&EmailAddress=EMAIL&Password=PASS";
byte[] postBytes = System.Text.Encoding.ASCII.GetBytes(postData);
request.ContentLength = postBytes.Length;
System.IO.Stream str = request.GetRequestStream();
str.Write(postBytes, 0, postBytes.Length);
str.Close();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
System.IO.Stream stream = response.GetResponseStream();
string html = new System.IO.StreamReader(stream).ReadToEnd();
Console.WriteLine("" + html);

You are trying to post something (I don't see, what, from your code) but not credentials. I guess that your web page shows you a web form where you enter username (email address?) and password. Then the browsers posts this form. Consequently you need to replicate browser behavior - encode form contents and send them in your post request. Use some webmaster developer tools for popular browsers to see what exactly the client browser sends to the server and how it encodes form data. Next, it's very likely that your request requires special cookies which you can collect by visiting another page (eg. login page). Sending preset cookies (like you do in commented code) won't work for most sites.
In other words, proper mechanism is:
GET the login web page
collect cookies
POST form data and pass collected cookies in the request.
collect other cookies, which could have been sent after login.

Login and retrieve data from embedded form page using C#

I'm a bit confused on how to go about this as I'm not really conversant with web stuff. I'm using a console application in C# to try and retrieve value from a page link inside a password protected homepage. I'm using the following details
Here's the code I'm trying:
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("");
req.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.0.3705;)";
req.Method = "POST";
req.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
req.Headers.Add("Accept-Language: en-us,en;q=0.5");
req.Headers.Add("Accept-Encoding: gzip,deflate");
req.Headers.Add("Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7");
req.KeepAlive = true;
req.Headers.Add("Keep-Alive: 300");
req.Referer = "copy from url";
req.ContentType = "application/x-www-form-urlencoded";
String Username = copy from url;
String PassWord = copy from url;
StreamWriter sw = new StreamWriter(req.GetRequestStream());
sw.Write(string.Format("&loginname={0}&password={1}&btnSubmit=Log In&institutioncode=H4V9KLUT45AV&version=2", Username, PassWord));
sw.Close();
HttpWebResponse response = (HttpWebResponse)req.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string tmp = reader.ReadToEnd();
However, when I inspect the data retrieved from the web page it shows something like this:
'...Your Session has timed out due to inactivity.Please logout and
relogin.return to login page>'
I'm guessing this is due to some VIEWSTATE stuff in ASP.NET
I'm also guessing I might have a problem with retrieving the data from the link I'll extract from the homepage, coz it seems the link simply loads data into a frame rather than reload the webpage.
Anyone please?

Your form data is incorrect. After removing the & at the beginning it worked for me:
sw.Write(string.Format("loginname={0}&password={1}&btnSubmit=Log In&institutioncode=H4V9KLUT45AV&version=2", Username, PassWord));
Additionally, as already mentioned in the other answer, you need to add the returned ASPSESSIONIDSSRRDRST cookie in further requests to the site.

Ok... the website is using Cookies, so, after you logged in you need to retrieve the cookies first, to make another WebRequest:
CookieCollection cookiesResponse = new CookieCollection();
if (response != null)
{
foreach (string cookie in response.Headers["Set-Cookie"].Split(';'))
{
string name = cookie.Split('=')[0];
string value = cookie.Substring(name.Length + 1);
cookiesResponse.Add(new Cookie(name.Trim(), value.Trim(), path, domain));
}
}
In you example the cookie contains: ASPSESSIONIDSSRRDRST=FEKODBMDBEIPCLLENCFLFBEA
You must use that CookieCollection for any request to the web, in your request you can set the cookies:
request.CookieContainer = cookiesResponse;
And finaly, you can parse the response. You can use an html tag parse, or parse the plain text.
I hope this is helpful.