I have an ASP.Net web application running on Windows Server 2012, and need to make calls to social networking sites using oauth to generate some of the page content. Everything works on my development machine, but I can't even get a single response back ("unable to connect to the remote server" error).
I disabled the firewall to test that. No luck. I created a console application to test it that way. A simple HttpWebRequest will get the html for any page I throw at it, but not any oauth request. I've used different libraries to try to achieve this, including Linq2Twitter, Spring.Social, and HigLabo. All work locally, but not on the server. I've found nothing useful in the server event log.
Can anyone give me some clues what might be happening?
EDIT: Here's some code I'm using with the HigLabo library to try to retrieve the user timeline.
using HigLabo.Net.Twitter;
var cl = new TwitterClient(consumerKey, consumerSecret, accessToken, accessTokenSecret);
var rr = cl.GetHomeTimeline();
foreach (var r in rr)
{
//Console.WriteLine(r.CreatedAt + ":" + r.Text);
}
I'm aware that accessToken & accessTokenSecret aren't/shouldn't be necessary for a simple timeline read, but this is just to make sure it works first.
This turned out to be a firewall issue, as had been suspected. But not the server firewall. This was a problem with the ISP. They had an internal firewall that was blocking all traffic to/from the social network sites. They were able to resolve it quickly with a phonecall, but it was not a coding or configuration error on my part.
Related
I have been working on this problem for quite some time. I've read the many similar posts and their solutions don't help me (many posts are old and stale). I have a new Xamarin project and a localhost API that I am testing to. Initially I installed our production API locally and it doesn't connect. So I created a smaller test API and have had varying results in connecting. Xamarin Android will not connect with a "Failed to connect to localhost:XXXXX" message. I built a WPF project and get the same results. However I can connect to outside public API's (github) with both. I can connect to my localhost with a Windows forms desktop app and successfully get & post. Postman and httprepl both connect locally and successfully get & post. A couple of the other things the other posts suggested are 1) Client handler to ignore SSL - doesn't work, 2) Use the emulator's browser to connect to localhost - cannot connect. (this might be exposing where the problem really is but not sure).
Also The debugger seems to be behaving oddly. When the debugger gets to the HttpResponseMessageresponse.... line it rarely makes it to the next line so I cannot inspect the statuscode. The block I have below is in a try/catch and rarely makes it to the catch if the connection truly fails. Sometimes it will be caught at the catch and that's how I get the "failed to connect" message. Another developer here has run the project on his computer and gets the same results/errors on his computer.
HttpResponseMessage response = await client.SendAsync(request);
var Statuscode = response.StatusCode;
if (response.IsSuccessStatusCode)
{
var jsonbody = response.Content.ReadAsStringAsync().Result;
var ResponseBody = JsonConvert.DeserializeObject(response.Content.ReadAsStringAsync().Result);
}
else
{
string oops = "Nothing";
}
I seem to be running out of options and am looking for any advice.
Thanks in advance.
We are using ASP.NET Identity with IdentityServer4. We've added a Client to use with Azure AD. This works great within a web page, that part is working.
Our end goal is a UWP app, so we found the IdentityModel.OidcClient which has a UWP sample. This sample has two browser classes. We configured HTTPS, but the WabBrowser class now refuses to connect to the site at all. If I change the config to hit https://demo.identityserver.io then it works, but all the other config is the same, so I'm not sure what the problem could be. It shows an error message in the pop up browser that it could not connect.
I looked at the SystemBrowser class, but this logs in fine, then the browser window does not close, and even if we close it, the code doesn't move on to get back a result. Looking at the source, this is not surprising, it calls:
Launcher.LaunchUriAsync(new Uri(options.StartUrl));
and that's all. The RedirectUri is not passed in, and mechanism appears to exist to use it. So, the behaviour we see appears to be the extent of what the class can do.
Looking at the console .NET Core sample, it has a SystemBrowser class that works. I updated the UWP sample to use the Fall Creators Update and was able to bring in the ASP.NET Core dlls needed to compile this code. It sets up a class like this:
public LoopbackHttpListener(int port, string path = null)
{
path = path ?? String.Empty;
if (path.StartsWith("/")) path = path.Substring(1);
_url = $"http://127.0.0.1:{port}/{path}";
_host = new WebHostBuilder()
.UseKestrel()
.UseUrls(_url)
.Configure(Configure)
.Build();
_host.Start();
}
and I can confirm this gets called only once, but even if I hard code an unused IP address, I get an error that the IP is in use.
So, at this stage, the sample that exists for UWP works for the demo server but not for ours (I suspect an HTTPS issue, but that's not the error I get), and importing code that works for a Core sample, does not work either. I've spent a couple of days on this and would appreciate a nudge in the right direction.
So, to recap, the WabBrowser seems the best bet but, for my localhost IdentityServer I get this:
and if I try to use a .NET Core library that works elsewhere, it thinks a port is in use. I suspect I need to work out why WabBrowser can't connect to my local site. I have turned off Fiddler. I can browse to my https URL and get a disco document, in the browser, at https://localhost:44305/.well-known/openid-configuration.
There are extra steps necessary to enable localhost in the Web Authentication Broker -
https://msdn.microsoft.com/en-us/library/windows/desktop/jj658959%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396
This website gave me the fix. Here is a synopsis:
Remove loopback isolation
For security and reliability reasons, UWP applications are not allowed to send requests to the loopback interface. While Visual Studio automatically creates exemptions for debugged apps, this feature won't be helpful in this case, as the authentication broker always executes in a separate process.
If you see this (cryptic) error message in your Windows event logs, then you're likely facing this issue:
AuthHost encountered a navigation error at URL: [...] with StatusCode: 0x800C0005.
One option to fix it is to use the loopack exemption utility developed by Eric Lawrence. It's natively included in Fiddler 4 but can also be downloaded as a standalone software. To allow the authentication broker to communicate with the loopback interface, exempt the applications starting with microsoft.windows.authhost and save your changes:
If everything was properly configured, you should now see the login/consent page returned by your server.
I have a Web app calling a Web Service by IP with the following code:
ws.Proxy = System.Net.HttpWebRequest.DefaultWebProxy;
ws.Credentials = System.Net.CredentialCache.DefaultCredentials;
ws.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
I believe this uses the IE proxy settings. I'm trying to troubleshoot a separate issue and want to confirm the default proxy details being used.
How do I do that?
I tried making sense of this:
How to AutoDetect/Use IE proxy settings in .net HttpWebRequest
I failed to get the proxy uri back using Scotty's link in the comments or this one:
https://msdn.microsoft.com/en-us/library/vs/alm/system.net.iwebproxy.getproxy(v=vs.110)
So had to use another approach to troubleshoot my app. Not an answer, just closing this out.
I've tried everything possible, to setup nJupiter.DataAccess.Ldap as the membership provider on our intranet based web application built using asp.net 3.5.
Challenges I am facing:
Not able to authenticate the user using the default login webpart (says Your login attempt was not successful. Please try again)
I tried this code and I receive a COMException : "There is no such object on the server."
var ldapMembershipUser = System.Web.Security.Membership.GetUser("username") as LdapMembershipUser;
if (ldapMembershipUser != null)
{
var givenName = ldapMembershipUser.Attributes["givenName"];
}
I have placed my web.config and the nJupiter.DataAccess.Ldap.config here:
web.config : http://pastebin.com/9XdDnhUH
nJupiter.DataAccess.Ldap.config : http://pastebin.com/WsSEhi98
I have tried all possible permutations and combinations for different values in the XML and i am not able to take it forward. Please guide. I just am not able to connec to the LDAP and authenticate the user or even search for users.
Just looking at your config is unlikely to be enough since I don't know your Domino server's confguration, so my answer isn't an attempt to fix your problem. It's an attempt to teach you how I would approach it if it were my problem. Here's what I do to troubleshoot connections and queries from code to Domino LDAP:
Configure the Domino LDAP server for logging the highest level of debug information with the notes.ini setting LDAPDEBUG=7. See this IBM technote for more info.
Use an LDAP client and figure out how to successfully connect to the Domino LDAP server. I like the free Softerra client for this. Check the logs and save off the info from your successful connection.
Now run your code and compare what you see in the logs against the successful connection.
If the code is making it past authentication but failing on the query, then find the actual query in the log, go back to your LDAP client, figure out what the query should have been, and adjust your code's configuration appropriately.
I'm tried to pull some SharePoint 2013 list data I created which works fine when running locally on my machine and when run locally one the server. I'm user the same credentials when running both locally and locally on the server. The issue is when I publish and navigate to my ASP.NET app on the server I get the "The remote server returned an error: (401) Unauthorized." Error...
I've looked at a bunch of the posts on stackoverflow and some other articles on the web
This points out that the context seems to be using IUSR:
http://blogs.msdn.com/b/sridhara/archive/2014/02/06/sharepoint-2013-csom-call-from-web-part-fails-with-401-for-all-users.aspx
This one mentions to try setting the default network credentials:
https://sharepoint.stackexchange.com/questions/10364/http-401-unauthorized-using-the-managed-client-object-model
I've tried using the fixes mentioned in the article as well as trying to force the context to use DefaultNetworkCredentials but no luck. I would like for the app to use the credentials of the logged in user and not the machine...
Here is the code I'm using:
SP.ClientContext context = new SP.ClientContext("MySPDevInstance");
context.Credentials = CredentialCache.DefaultNetworkCredentials;
Entity entity = context.Web.GetEntity(collectionNamespace, collectionName);
LobSystem lobSystem = entity.GetLobSystem();
LobSystemInstanceCollection lobSystemInstanceCollection = lobSystem.GetLobSystemInstances();
context.Load(lobSystemInstanceCollection);
context.ExecuteQuery();
LobSystemInstance lobSystemInstance = lobSystemInstanceCollection[0];
FilterCollection filterCollection = entity.GetFilters(filter);
filterCollection.SetFilterValue("LimitFilter", 0, 1000);
EntityInstanceCollection items = entity.FindFiltered(filterCollection, filter, lobSystemInstance);
The server is running IIS 6.0
Any advice would be much appreciated!
Thank you
I presume your ASP.NET web site is using Windows Integrated (NTLM) authentication. A user authenticated this way cannot authenticate to a second location from the server side (the web server.) You are experiencing what is known as the "double-hop" (1) limitation of NTLM. You must use a dedicated account on the server side, or if you really do want to use the logged-in user's identity, you must use an authentication scheme that permits delegation, such as Kerberos.
If you really need the user's identity to access SharePoint data and you cannot change the authentication scheme, then the best way to do this is to use the JavaScript CSOM. This means the user is authenticating directly to the SharePoint server (a single hop, not double) and your ASP.NET site serves the page containing this script to the user.
(1) http://blogs.msdn.com/b/knowledgecast/archive/2007/01/31/the-double-hop-problem.aspx
Use Default Credentials worked for me:
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
httpWebRequest.UseDefaultCredentials = true;
Setup the crendentials by code:
SP.ClientContext context = new SP.ClientContext("MySPDevInstance");
context.Credentials = new NetworkCredential("username", "password");
You should put this at the configuration file to change it without publishing or recompiling the application.
Just to add one more setting that I encountered. If the account is restricted to access only certain servers than add the client machine to that account as well. For example if a web application is hosted on Server A and trying to connect to SharePoint 2010 on Server B with account ABC then make sure that account has access to Server A in Active Directory. Normally the AD account doesn't have restrictions to connect to machines but in my case the account was restricted to only certain machines. I added my web application hosted server to the account and it worked.