Develop Reference

Xamarin.Android: How Can I Pass WebView Login Creds Into HttpWebRequest?

I am trying to pass login creds from a WebView into an HttpWebRequest but not having any luck getting an authenticated response. I am able to successfully make the request, but the response is acting like I haven't logged in. My app has 5 WebViews contained within Fragment s and I'm logged in on all of them. I've tried using the CookieSyncManager but it's deprecated and .Sync() didn't work. I've tried a lot of different ways of passing the cookies into the HttpRequest with no success and many hours spent.
One would think this is a simple request; user has logged in within the app; they should be authenticated for all requests. Here's the closest that I've gotten, but the response string is still not the same as through my authenticated WebView :
This attempt parses each Cookie into a string and adds it
public string _cookieString { get; set; }
private class ExtWebViewClient : WebViewClient
{
TheFragment5 _fm5 = new TheFragment5();
public override void OnPageFinished(WebView view, string url)
{
var cookieHeader = Android.Webkit.CookieManager.Instance.GetCookie(url);
var cookiePairs = cookieHeader.Split('&');
_fm5._cookieString = "";
foreach (var cookiePair in cookiePairs)
{
var cookiePieces = cookiePair.Split('=');
if (cookiePieces[0].Contains(":"))
cookiePieces[0] = cookiePieces[0].Substring(0, cookiePieces[0].IndexOf(":"));
cookies.Add(new Cookie
{
Name = cookiePieces[0],
Value = cookiePieces[1]
});
}
foreach (Cookie c in cookies)
{
if (_fm5._cookieString == "")
{
_fm5._cookieString = c.ToString();
}
else
{
_fm5._cookieString += c.ToString();
}
}
}
}
I've also tried just doing:
_fm5._cookieString = cookieHeader.ToString();
but neither of those attempts is working when I add the cookie string into my HttpRequest :
public async void GetNotificationText(string url)
{
//var _cmhc = _cookieMan.HasCookies;
await Task.Run(() =>
{
_notificationHttpRequestInProgress = true;
try
{
var _ctxxx = Android.App.Application.Context;
//URL _url2 = new URL("https://bitchute.com/notifications/");
//HttpURLConnection conn = (HttpURLConnection)_url2.OpenConnection();
//conn.ReadTimeout = 10000 /* milliseconds */;
//conn.ConnectTimeout = 15000 /* milliseconds */;
////conn.SetRequestProperty("Cookie", cookies);
//conn.Connect();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
Uri uri = new Uri(url);
var _req = request;
var _uriii = uri;
var _cookiesss = _fm5._cookieString;
_cookieCon.SetCookies(uri, _cookiesss);
request.CookieContainer = _cookieCon;
//request.CookieContainer.SetCookies(uri, _cookiesss);
request.AutomaticDecompression = DecompressionMethods.GZip;
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
using (Stream stream = response.GetResponseStream())
using (StreamReader reader = new StreamReader(stream))
{
_notificationRawText = reader.ReadToEnd();
Console.WriteLine(_notificationRawText);
_rawNoteText = _notificationRawText;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
_notificationHttpRequestInProgress = false;
});
}
This returns, but not the authenticated webtext request; I get the same response any user would get on a browser having never logged in. If I were to browse out to this same url on any WebView in my app, I'd get a completely different response.
You will also notice some commented out code that was another failed attempt at adding the cookies into a connection. I had also tried using HttpURLConnection.SetRequestProperty("Cookie", cookies);
where cookies was a CookieCollection and that didn't work either. The code is mostly commented out and layered because I've been trying this for days.
Does anyone know how I can pass WebView cookies into an HttpRequest using Xamarin.Android?
I am putting this code below in Fragment5 of my app; you can see and compile the full context here:
https://github.com/hexag0d/BitChute_Mobile_Android_BottomNav/blob/NotificationAdder/Fragments/TheFragment5.cs

I'm not sure exactly why the above example didn't work; maybe if you're better at .NET than I am, you could figure it out. However, I was able to successfully pass WebView creds into an HttpClient by following these steps, which are returning an authenticated response. This may not be the most elegant way of doing it, but you can always refine my answer, or post a better one.
What I had to do was set the HttpClient.DefaultRequestHeaders using the .Add() method like this: _client.DefaultRequestHeaders.Add("Cookie", TheFragment5._cookieHeader);
I got the CookieHeader (which is just a string btw) like this:
//instantiate a string that will house our cookie header
public static string _cookieHeader;
//you might want to make it private to prevent abuse
//but this example is just for demonstration
//the thing is we need a string to house our headers in scope of both the WebView and the HttpClient
//extend the WebViewClient
private class ExtWebViewClient : WebViewClient
{
public override void OnPageFinished(WebView view, string url)
{
//I get the cookies when the page finishes loading because
//then we know the cookie has our login cred header
//also, most of the previous examples got the cookies OnPageFinished
TheFragment5._cookieHeader = Android.Webkit.CookieManager.Instance.GetCookie(url);
}
}
Then we need another method for the HttpClient and HttpClientHandler ... mine scans a webpage for notification text.
public async void GetNotificationText(string url)
{
await Task.Run(() =>
{
/* this line is pretty important,
we need to instantiate an HttpClientHandler
then set it's UseCookies property to false
so that it doesn't override our cookies
*/
HttpClientHandler handler = new HttpClientHandler() { UseCookies = false };
try
{
Uri _notificationURI = new Uri("https://bitchute.com/notifications/");
//instantiate HttpClient using the handler
using (HttpClient _client = new HttpClient(handler))
{
//this line is where the magic happens;
//we set the DefaultRequestHeaders with the cookieheader we got from WebViewClient.OnPageFinished
_client.DefaultRequestHeaders.Add("Cookie", TheFragment5._cookieHeader);
//do a GetAsync request with our cookied up client
var getRequest = _client.GetAsync("https://bitchute.com/notifications/").Result;
//resultContent is the authenticated html string response from the server, ready to be parsed =]
var resultContent = getRequest.Content.ReadAsStringAsync().Result;
/*
I was writing to console to check the
response.. for me, I am now getting
the authenticated notification html
page
*/
Console.WriteLine(resultContent);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
Hope this helps you, posting for future reference, especially for people using Xamarin.Android.

How to execute two dependent odata url's in same session from C# Code

I need to call two odata URL's of sap from C# Code.
The first URL will set the Filters and the second URL (generic URL) will give the actual response.
First URL:
https://<>/sap/opu/odata/SALM/TM_SERVICE/setFilters?sap-language=EN&filter='2%2Ctime%3D%E2%80%8E4%E2%80%8E%2F%E2%80%8E1%E2%80%8E%2F%E2%80%8E2019%E2%80%8E%20%E2%80%8E10%E2%80%8E%3A%E2%80%8E31%E2%80%8E%3A%E2%80%8E24%E2%80%8E%20%E2%80%8EAMc%3ATest%20Suite%20for%20Focused%20Build%2Cw%3A%2CT%3D<>'
Second URL :
https://<>//sap/opu/odata/SALM/TM_SERVICE/TILECollection(ConfigID='1%20',PageID='2%20',TileID='8%20')?$format=json&sap-language=EN
Second URL is generic and constant URL but after first execution of first URL with different parameter values second URL will give different response.
In a browser I am able to execute these two URL's and see the response difference with different parameter values.
Need C# Code to simulate the browser behavior. In C# Code second URL response is constant and not being changed.
Tried using following : WebRequest,HttpWebRequest, HttpClient,WebClient along with passing cookie ( cookie received from First response is passed to Request while executing the second url )
var httpClientHandler = new HttpClientHandler()
{
Credentials = credential,
CookieContainer = cookieContainer
};
using (HttpClient client = new HttpClient(httpClientHandler))
{
using (HttpResponseMessage response = client.GetAsync("<<first url>>").Result)
{
Uri uri = new Uri(string.Format(ConfigurationManager.AppSettings["TestPlanSetFilters"], s));
IEnumerable<Cookie> responseCookies = cookieContainer.GetCookies(uri).Cast<Cookie>();
foreach (Cookie cookie in responseCookies)
{
cookieContainer.Add(cookie);
}
}
using (HttpResponseMessage response1 = client.GetAsync("<<second url>>").Result)
{
using (HttpContent content1 = response1.Content)
{
var json2 = content1.ReadAsStringAsync().Result;
}
}
}

C#: HttpWebRequest POST data not working

I am developing a C# wpf application that has a functionality of logging into my website and download the file. This said website has an Authorize attribute on its action. I need 2 cookies for me to able to download the file, first cookie is for me to log in, second cookie(which is provided after successful log in) is for me to download the file. So i came up with the flow of keeping my cookies after my httpwebrequest/httpwebresponse. I am looking at my posting flow as maybe it is the problem. Here is my code.
void externalloginanddownload()
{
string pageSource = string.Empty;
CookieContainer cookies = new CookieContainer();
HttpWebRequest getrequest = (HttpWebRequest)WebRequest.Create("login uri");
getrequest.CookieContainer = cookies;
getrequest.Method = "GET";
getrequest.AllowAutoRedirect = false;
HttpWebResponse getresponse = (HttpWebResponse)getrequest.GetResponse();
using (StreamReader sr = new StreamReader(getresponse.GetResponseStream()))
{
pageSource = sr.ReadToEnd();
}
var values = new NameValueCollection
{
{"Username", "username"},
{"Password", "password"},
{ "Remember me?","False"},
};
var parameters = new StringBuilder();
foreach (string key in values.Keys)
{
parameters.AppendFormat("{0}={1}&",
HttpUtility.UrlEncode(key),
HttpUtility.UrlEncode(values[key]));
}
parameters.Length -= 1;
HttpWebRequest postrequest = (HttpWebRequest)WebRequest.Create("login uri");
postrequest.CookieContainer = cookies;
postrequest.Method = "POST";
using (var writer = new StreamWriter(postrequest.GetRequestStream()))
{
writer.Write(parameters.ToString());
}
using (WebResponse response = postrequest.GetResponse()) // the error 500 occurs here
{
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
string html = streamReader.ReadToEnd();
}
}
}

When you get the WebResponse, the cookies returned will be in the response, not in the request (oddly enough, even though you need to CookieContainer on the request).
You will need to add the cookies from the response object to your CookieContainer, so it gets sent on the next request.
One simple way:
for(var cookie in getresponse.Cookies)
cookies.Add(cookie)
Since the cookies in response is already a cookies container, you can do this (might help to check for null in case all cookies were already there)
if (response.Cookies != null) cookies.Add(response.Cookies)
You may also have trouble with your POST as you need to set ContentType and length:
myWebRequest.ContentLength = parameters.Length;
myWebRequest.AllowWriteStreamBuffering = true;
If you have any multibyte characters to think about, you may have to address that as well by setting the encoding to UTF-8 on the request and the stringbuilder, and converting string to bytes and using that length.
Another tip: some web server code chokes if there is no user agent. Try:
myWebRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";
And just in case you have any multibyte characters, it is better to do this:
var databytes = System.Text.Encoding.UTF8.GetBytes(parameters.ToString());
myWebRequest.ContentLength = databytes.Length;
myWebRequest.ContentType = "application/x-www-form-urlencoded; charset=utf-8";
using (var stream = myWebRequest.GetRequestStream())
{
stream.Write(databytes, 0, databytes.Length);
}

In C# Application (Server side Web API) Enable the C++ Exception and Common Language Run time Exceptions using (Ctrl+Alt+E) what is the Server side Exception it's throw.
First you check data is binding Properly. After you can see what it is Exact Exception. the Internal Server Error Mostly throw the data is not correct format and not properly managed Exception.

.NETCore HttpWebRequest - Old Way isn't Working

Before I upgraded to the newest .NetCore I was able to run the HttpWebRequest, add the headers and content Type and pull the stream of the JSON file from Twitch. Since the upgrade this is not working. I receive a Web Exception each time I go to get the response Stream. Nothing has changed with twitch because it still works with the old Bot. The old code is below:
private const string Url = "https://api.twitch.tv/kraken/streams/channelname";
HttpWebRequest request;
try
{
request = (HttpWebRequest)WebRequest.Create(Url);
}
request.Method = "Get";
request.Timeout = 12000;
request.ContentType = "application/vnd.twitchtv.v5+json";
request.Headers.Add("Client-ID", "ID");
try
{
using (var s = request.GetResponse().GetResponseStream())
{
if (s != null)
using (var sr = new StreamReader(s))
{
}
}
}
I have done some research and found that I may need to start using either an HttpClient or HttpRequestMessage. I have tried going about this but when adding headers content type the program halts and exits. after the first line here: (when using HttpsRequestMessage)
request.Content.Headers.ContentType.MediaType = "application/vnd.twitchtv.v5+json";
request.Content.Headers.Add("Client-ID", "rbp1au0xk85ej6wac9b8s1a1amlsi5");

You are trying to add a ContentType header, but what you really want is to add an Accept header (your request is a GET and ContentType is used only on requests which contain a body, e.g. POST or PUT).
In .NET Core you need to use HttpClient, but remember that to correctly use it you need to leverage the use of async and await.
Here it is an example:
using System.Net.Http;
using System.Net.Http.Headers;
private const string Url = "https://api.twitch.tv/kraken/streams/channelname";
public static async Task<string> GetResponseFromTwitch()
{
using(var client = new HttpClient())
{
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/vnd.twitchtv.v5+json"));
client.DefaultRequestHeaders.Add("Client-ID", "MyId");
using(var response = await client.GetAsync(Url))
{
response.EnsureSuccessStatusCode();
return await response.Content.ReadAsStringAsync(); // here we return the json response, you may parse it
}
}
}

Problems authenticating to website from code

I am trying to write code that will authenticate to the website wallbase.cc. I've looked at what it does using Firfebug/Chrome Developer tools and it seems fairly easy:
Post "usrname=$USER&pass=$PASS&nopass_email=Type+in+your+e-mail+and+press+enter&nopass=0" to the webpage "http://wallbase.cc/user/login", store the returned cookies and use them on all future requests.
Here is my code:
private CookieContainer _cookies = new CookieContainer();
//......
HttpPost("http://wallbase.cc/user/login", string.Format("usrname={0}&pass={1}&nopass_email=Type+in+your+e-mail+and+press+enter&nopass=0", Username, assword));
//......
private string HttpPost(string url, string parameters)
{
try
{
System.Net.WebRequest req = System.Net.WebRequest.Create(url);
//Add these, as we're doing a POST
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
((HttpWebRequest)req).Referer = "http://wallbase.cc/home/";
((HttpWebRequest)req).CookieContainer = _cookies;
//We need to count how many bytes we're sending. Post'ed Faked Forms should be name=value&
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(parameters);
req.ContentLength = bytes.Length;
System.IO.Stream os = req.GetRequestStream();
os.Write(bytes, 0, bytes.Length); //Push it out there
os.Close();
//get response
using (System.Net.WebResponse resp = req.GetResponse())
{
if (resp == null) return null;
using (Stream st = resp.GetResponseStream())
{
System.IO.StreamReader sr = new System.IO.StreamReader(st);
return sr.ReadToEnd().Trim();
}
}
}
catch (Exception)
{
return null;
}
}
After calling HttpPost with my login parameters I would expect all future calls using this same method to be authenticated (assuming a valid username/password). I do get a session cookie in my cookie collection but for some reason I'm not authenticated. I get a session cookie in my cookie collection regardless of which page I visit so I tried loading the home page first to get the initial session cookie and then logging in but there was no change.
To my knowledge this Python version works: https://github.com/sevensins/Wallbase-Downloader/blob/master/wallbase.sh (line 336)
Any ideas on how to get authentication working?
Update #1
When using a correct user/password pair the response automatically redirects to the referrer but when an incorrect user/pass pair is received it does not redirect and returns a bad user/pass pair. Based on this it seems as though authentication is happening, but maybe not all the key pieces of information are being saved??
Update #2
I am using .NET 3.5. When I tried the above code in .NET 4, with the added line of System.Net.ServicePointManager.Expect100Continue = false (which was in my code, just not shown here) it works, no changes necessary. The problem seems to stem directly from some pre-.Net 4 issue.

This is based on code from one of my projects, as well as code found from various answers here on stackoverflow.
First we need to set up a Cookie aware WebClient that is going to use HTML 1.0.
public class CookieAwareWebClient : WebClient
{
private CookieContainer cookie = new CookieContainer();
protected override WebRequest GetWebRequest(Uri address)
{
HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(address);
request.ProtocolVersion = HttpVersion.Version10;
if (request is HttpWebRequest)
{
(request as HttpWebRequest).CookieContainer = cookie;
}
return request;
}
}
Next we set up the code that handles the Authentication and then finally loads the response.
var client = new CookieAwareWebClient();
client.UseDefaultCredentials = true;
client.BaseAddress = #"http://wallbase.cc";
var loginData = new NameValueCollection();
loginData.Add("usrname", "test");
loginData.Add("pass", "123");
loginData.Add("nopass_email", "Type in your e-mail and press enter");
loginData.Add("nopass", "0");
var result = client.UploadValues(#"http://wallbase.cc/user/login", "POST", loginData);
string response = System.Text.Encoding.UTF8.GetString(result);
We can try this out using the HTML Visualizer inbuilt into Visual Studio while staying in debug mode and use that to confirm that we were able to authenticate and load the Home page while staying authenticated.
The key here is to set up a CookieContainer and use HTTP 1.0, instead of 1.1. I am not entirely sure why forcing it to use 1.0 allows you to authenticate and load the page successfully, but part of the solution is based on this answer.
https://stackoverflow.com/a/10916014/408182
I used Fiddler to make sure that the response sent by the C# Client was the same as with my web browser Chrome. It also allows me to confirm if the C# client is being redirect correctly. In this case we can see that with HTML 1.0 we are getting the HTTP/1.0 302 Found and then redirects us to the home page as intended. If we switch back to HTML 1.1 we will get an HTTP/1.1 417 Expectation Failed message instead.
There is some information on this error message available in this stackoverflow thread.
HTTP POST Returns Error: 417 "Expectation Failed."
Edit: Hack/Fix for .NET 3.5
I have spent a lot of time trying to figure out the difference between 3.5 and 4.0, but I seriously have no clue. It looks like 3.5 is creating a new cookie after the authentication and the only way I found around this was to authenticate the user twice.
I also had to make some changes on the WebClient based on information from this post.
http://dot-net-expertise.blogspot.fr/2009/10/cookiecontainer-domain-handling-bug-fix.html
public class CookieAwareWebClient : WebClient
{
public CookieContainer cookies = new CookieContainer();
protected override WebRequest GetWebRequest(Uri address)
{
var request = base.GetWebRequest(address);
var httpRequest = request as HttpWebRequest;
if (httpRequest != null)
{
httpRequest.ProtocolVersion = HttpVersion.Version10;
httpRequest.CookieContainer = cookies;
var table = (Hashtable)cookies.GetType().InvokeMember("m_domainTable", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.GetField | System.Reflection.BindingFlags.Instance, null, cookies, new object[] { });
var keys = new ArrayList(table.Keys);
foreach (var key in keys)
{
var newKey = (key as string).Substring(1);
table[newKey] = table[key];
}
}
return request;
}
}
var client = new CookieAwareWebClient();
var loginData = new NameValueCollection();
loginData.Add("usrname", "test");
loginData.Add("pass", "123");
loginData.Add("nopass_email", "Type in your e-mail and press enter");
loginData.Add("nopass", "0");
// Hack: Authenticate the user twice!
client.UploadValues(#"http://wallbase.cc/user/login", "POST", loginData);
var result = client.UploadValues(#"http://wallbase.cc/user/login", "POST", loginData);
string response = System.Text.Encoding.UTF8.GetString(result);

You may need to add the following:
//get response
using (System.Net.WebResponse resp = req.GetResponse())
{
foreach (Cookie c in resp.Cookies)
_cookies.Add(c);
// Do other stuff with response....
}
Another thing that you might have to do is, if the server responds with a 302 (redirect) the .Net web request will automatically follow it and in the process you might lose the cookie you're after. You can turn off this behavior with the following code:
req.AllowAutoRedirect = false;

The Python you reference uses a different referrer (http://wallbase.cc/start/). It is also followed by another post to (http://wallbase.cc/user/adult_confirm/1). Try the other referrer and followup with this POST.
I think you are authenticating correctly, but that the site needs more info/assertions from you before proceeding.