Target Machine Actively Refused Connection - c#

There are several questions like this, but my situation seems a bit different. I have extremely simple code:
WebClient client = new WebClient();
client.DownloadFile("http://www.xkcd.com", "xkcd.html");
However, I get the error "No connection could be made because target machine actively refused the connection." However, I also see this problem with connections to any website. It also only appears in .NET applications, all of a sudden, none of them can access the web.
Any ideas?

For the purpose of a sanity check, I like using PowerShell to call api's, so I'd suggest that if you can.
Also, make sure to try that url in IE on the system just to make sure there's nothing weird going on (forced proxy, site is really down, DNS or hosts file is resolving it to something else, etc).
C:\Users\james » $wc = new-object system.net.webclient
C:\Users\james » $wc.DownloadFile("http://www.xkcd.com", "xkcd.html")
C:\Users\james » dir .\xkcd.html
Directory: Microsoft.PowerShell.Core\FileSystem::C:\Users\james
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 8/26/2010 1:08 AM 7454 xkcd.html

The user that your code is running as is relevant. For example the code might work in a console/WinForms app but not in an ASP.NET app.

Try to go to the site using Internet Explorer browser. The problem is the WebClient uses proxy settings from IE. And there are any wrong proxy settings you'll get the message you've got.

Related

Properly configuring a dotnet (ASP.NET Core 2.1) environment on CentOS / Linux

I'm stuck, I'm really hoping someone can help or at least point me in the right direction. My end goal is to get my ASP.NET Core 2.1 app running on a CentOS Linux box. Since I'm using a mongo db in my actual app and wanted to eliminate any possible issues with that, I published a plain-jane asp.net core 2.1 mvc app, no authentication, and deployed it to a virtual host on my centos 7 box (apache upgraded via CoreIT to 2.4.37 since centos distros still deploy the older 2.4.6 version).
For the scope of this question I think I just need to make sure my reverse proxy is working properly and need help in pinning down that. I've followed instructions from here and the Microsoft setup doc from here. These 2 links are what I've been working with mainly.
When my app service is running, I can do a curl localhost:5000 and see the correct html of my homepage being returned. When I try from command line again with test.mydomain.com or test.mydomain.com:5000 it just times out. If I go to my app's conf (test.mydomain.com.conf in /etc/httpd/sites-available) and remove the ProxyPass, ProxyPassReverse and ProxyPreserveHost lines then I can hit test.mydomain.com from the outside with a browser and get my index.html file up and displaying properly (this is just one index.html file and not a part of the dotnet app though). It's only when I add the below back into my conf file it just hangs up when I try and hit the URL. I'm not sure what to look for in journalctl or maybe I should tail a specific log file to find out what it's waiting on and why it's taking so long.
ProxyPreserveHost On
ProxyPass / http://127.0.0.1:5000/
ProxyPassReverse / http://127.0.0.1:5000/
Somehow is seems like my reverse proxy isn't set up right to be accessed from outside the box.
The rest of my app's config below.
<VirtualHost *:*>
RequestHeader set "X-Forwarded-Proto" expr=%{REQUEST_SCHEME}</VirtualHost>
<VirtualHost *:80>
ServerName test.mydomain.com
DocumentRoot /var/www/test.mydomain.com/public_html
ErrorLog logs/dashboard.crtv1.com.errorlog
CustomLog logs/dashboard.crtv1.com.access_log combined
</VirtualHost>
I think I addressed the issue although I'm not sure what issues I was actually having at the time of posting. I ended up through process of elimination and curl to find another service was running and using port 5000 in another virtual host - we're doing development and need a test, staging and production set of virtual hosts. Also I found I had some code in my app (UseUrls) that was specifically stating to use port 5000 so multiple copies of it within the same environment had resource conflicts. I'll circle back and update which environments will use which ports and hopefully have a nice set up.

how to redirect twitter app's call bak url to localhost? [duplicate]

Is anyone else having a difficult time getting Twitters oAuth's callback URL to hit their localhost development environment.
Apparently it has been disabled recently. http://code.google.com/p/twitter-api/issues/detail?id=534#c1
Does anyone have a workaround. I don't really want to stop my development
Alternative 1.
Set up your .hosts (Windows) or etc/hosts file to point a live domain to your localhost IP. such as:
127.0.0.1 xyz.example
where xyz.example is your real domain.
Alternative 2.
Also, the article gives the tip to alternatively use a URL shortener service. Shorten your local URL and provide the result as callback.
Alternative 3.
Furthermore, it seems that it works to provide for example http://127.0.0.1:8080 as callback to Twitter, instead of http://localhost:8080.
I just had to do this last week. Apparently localhost doesn't work but 127.0.0.1 does Go figure.
This of course assumes that you are registering two apps with Twitter, one for your live www.mysite.example and another for 127.0.0.1.
Just put http://127.0.0.1:xxxx/ as the callback URL, where xxxx is the port for your framework
Yes, it was disabled because of the recent security issue that was found in OAuth. The only solution for now is to create two OAuth applications - one for production and one for development. In the development application you set your localhost callback URL instead of the live one.
Callback URL edited
http://localhost:8585/logintwitter.aspx
Convert to
http://127.0.0.1:8585/logintwitter.aspx
This is how i did it:
Registered Callback URL:
http://127.0.0.1/Callback.aspx
OAuthTokenResponse authorizationTokens =
OAuthUtility.GetRequestToken(ConfigSettings.getConsumerKey(),
ConfigSettings.getConsumerSecret(),
"http://127.0.0.1:1066/Twitter/Callback.aspx");
ConfigSettings:
public static class ConfigSettings
{
public static String getConsumerKey()
{
return System.Configuration.ConfigurationManager.AppSettings["ConsumerKey"].ToString();
}
public static String getConsumerSecret()
{
return System.Configuration.ConfigurationManager.AppSettings["ConsumerSecret"].ToString();
}
}
Web.config:
<appSettings>
<add key="ConsumerKey" value="xxxxxxxxxxxxxxxxxxxx"/>
<add key="ConsumerSecret" value="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"/>
</appSettings>
Make sure you set the property 'use dynamic ports' of you project to 'false' and enter a static port number instead. (I used 1066).
I hope this helps!
Use http://smackaho.st
What it does is a simple DNS association to 127.0.0.1 which allows you to bypass the filters on localhost or 127.0.0.1 :
smackaho.st. 28800 IN A 127.0.0.1
So if you click on the link, it will display you what you have on your local webserver (and if you don't have one, you'll get a 404). You can of course set it to any page/port you want :
http://smackaho.st:54878/twitter/callback
I was working with Twitter callback url on my localhost. If you are not sure how to create a virtual host ( this is important ) use Ampps. He is really cool and easy. In a few steps you have your own virtual host and then every url will work on it. For example:
download and install ampps
Add new domain. ( here you can set for example twitter.local) that means your virtual host will be http://twitter.local and it will work after step 3.
I am working on Win so go under to your host file -> C:\Windows\System32\Drivers\etc\hosts and add line: 127.0.0.1 twitter.local
Restart your Ampps and you can use your callback. You can specify any url, even if you are using some framework MVC or you have htaccess url rewrite.
Hope This Help!
Cheers.
Seems nowadays http://127.0.0.1 also stopped working.
A simple solution is to use http://localtest.me instead of http://localhost it is always pointing to 127.0.0.1 And you can even add any arbitrary subdomain to it, and it will still point to 127.0.0.1
See Website
When I develop locally, I always set up a locally hosted dev name that reflects the project I'm working on. I set this up in xampp through xampp\apache\conf\extra\httpd-vhosts.conf and then also in \Windows\System32\drivers\etc\hosts.
So if I am setting up a local dev site for example.com, I would set it up as example.dev in those two files.
Short Answer: Once this is set up properly, you can simply treat this url (http://example.dev) as if it were live (rather than local) as you set up your Twitter Application.
A similar answer was given here: https://dev.twitter.com/discussions/5749
Direct Quote (emphasis added):
You can provide any valid URL with a domain name we recognize on the
application details page. OAuth 1.0a requires you to send a
oauth_callback value on the request token step of the flow and we'll
accept a dynamic locahost-based callback on that step.
This worked like a charm for me. Hope this helps.
It can be done very conveniently with Fiddler:
Open menu Tools > HOSTS...
Insert a line like 127.0.0.1 your-production-domain.com, make sure that "Enable remapping of requests..." is checked. Don't forget to press Save.
If access to your real production server is needed, simply exit Fiddler or disable remapping.
Starting Fiddler again will turn on remapping (if it is checked).
A pleasant bonus is that you can specify a custom port, like this:
127.0.0.1:3000 your-production-domain.com (it would be impossible to achieve this via the hosts file). Also, instead of IP you can use any domain name (e.g., localhost).
This way, it is possible (but not necessary) to register your Twitter app only once (provided that you don't mind using the same keys for local development and production).
edit this function on TwitterAPIExchange.php at line #180
public function performRequest($return = true)
{
if (!is_bool($return))
{
throw new Exception('performRequest parameter must be true or false');
}
$header = array($this->buildAuthorizationHeader($this->oauth), 'Expect:');
$getfield = $this->getGetfield();
$postfields = $this->getPostfields();
$options = array(
CURLOPT_HTTPHEADER => $header,
CURLOPT_HEADER => false,
CURLOPT_URL => $this->url,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => false
);
if (!is_null($postfields))
{
$options[CURLOPT_POSTFIELDS] = $postfields;
}
else
{
if ($getfield !== '')
{
$options[CURLOPT_URL] .= $getfield;
}
}
$feed = curl_init();
curl_setopt_array($feed, $options);
$json = curl_exec($feed);
curl_close($feed);
if ($return) { return $json; }
}
I had the same challenge and I was not able to give localhost as a valid callback URL. So I created a simple domain to help us developers out:
https://tolocalhost.com
It will redirect any path to your localhost domain and port you need. Hope it can be of use to other developers.
set callbackurl in twitter app : 127.0.0.1:3000
and set WEBrick to bind on 127.0.0.1 instead of 0.0.0.0
command : rails s -b 127.0.0.1
Looks like Twitter now allows localhost alongside whatever you have in the Callback URL settings, so long as there is a value there.
I struggled with this and followed a dozen solutions, in the end all I had to do to work with any ssl apis on local host was:
Go download: cacert.pem file
In php.ini * un-comment and change:
curl.cainfo = "c:/wamp/bin/php/php5.5.12/cacert.pem"
You can find where your php.ini file is on your machine by running php --ini in your CLI
I placed my cacert.pem in the same directory as php.ini for ease.
These are the steps that worked for me to get Facebook working with a local application on my laptop:
goto apps.twitter.com
enter the name, app description and your site URL
Note: for localhost:8000, use 127.0.0.1:8000 since the former will not work
enter the callback URL matching your callback URL defined in TWITTER_REDIRECT_URI your application
Note: eg: http://127.0.0.1/login/twitter/callback (localhost will not work).
Important enter both the "privacy policy" and "terms of use" URLs if you wish to request the user's email address
check the agree to terms checkbox
click [Create Your Twitter Application]
switch to the [Keys and Access Tokens] tab at the top
copy the "Consumer Key (API Key)" and "Consumer Secret (API Secret)" to TWITTER_KEY and TWITTER_SECRET in your application
click the "Permissions" tab and set appropriately to "read only", "read and write" or "read, write and direct message" (use the least intrusive option needed for your application, for just and OAuth login "read only" is sufficient
Under "Additional Permissions" check the "request email addresses from users" checkbox if you wish for the user's email address to be returned to the OAuth login data (in most cases check yes)

Get original url without non-standard port (C#)

First question!
Environment
MVC, C#, AppHarbor.
Problem
I am calling an openid provider, and generating an absolute callback url based on the domain.
On my local machine, this works fine if I hit http://localhost:12345/login
Request.Url; //gives me `http://localhost:12345/callback`
However, on AppHarbor where I'm deploying, because they are using non-standard ports, even if I'm hitting it at "http://sub.example.com/login"
Request.Url; //gives me http://sub.example.com:15232/callback
And this screws up my callback, because the port number wasn't in the original source url!
I've tried
Request.Url
Request.Url.OriginalString
Request.RawUrl
All gives me "http://sub.example.com:15232/callback".
Also to clear up that this isn't a Realm issue, the error message I am getting from DotNetOpenAuth is
'http://sub.example.com:14107/accounts/openidcallback' not under realm 'http://*.example.com/'.
I don't think I've stuffed that up?
Now, I'm about to consider some hacky stuff like
preprocessor commands (#IF DEBUG THEN PUT PORT)
string replace (Request.URL.Contains("localhost"))
All of these are not 100% solutions, but I'm sick of mulling over what could be a simple property that I am missing. I have also read this but that doesn't seem to have an accepted answer (and is more about the path rather than the authority). So I'm putting it towards you guys.
Summary
So if I had http://localhost:12345/login, I need to get http://localhost:12345/callback from the Request context.
And if I had "http://sub.example.com/login", I should get "http://sub.example.com/callback", regardless of what port it is on.
Thanks! (Sleep time, will answer any questions in the morning)
This is a common problem in load balanced setups like AppHarbor's - we've provided an example workaround.
Update: A more desirable solution for many ASP.NET applications may be to set the aspnet:UseHostHeaderForRequestUrl appSetting to true. We (AppHarbor) have seen several customers experience issues using it with their WCF apps, which is why we haven't enabled it by default and stil recommend the above solution for those situations. You can configure it using AppHarbor's "Configuration Variables" to inject the appsettings when deployed. More information can be found in this article.
I recently ran into an issue where I compared a URL to the current URL, and then highlighted navigation based on that. It worked locally, but not in production.
I had http://example.com/path/to/file.aspx as my file, but when viewing that file and running Request.Url.ToString() it produced https://example.com:81/path/to/file.aspx in a load balanced production environment.
Now I am using Request.Url.AbsolutePath to just give me /path/to/file.aspx, thus ignoring the schema, hostname, and port numbers.
When I need to compare it to the URL on each navigation item I used:
New Uri(theLink.Href).AbsolutePath
My initial thoughts are get the referrer variable and check if that includes a port, if so use it otherwise don't.
If that’s not an option because a proxy might remove the referrer header variable then you might need to use some client side script to get the location and pass it back to the server.
I'm guessing that AppHarbor use port forwarding to the IIS server so even though publicly the site is on port 80 IIS has it hosted on another port so it can't know what port the client connected on.
Something like
String port = Request.ServerVariables["SERVER_PORT"] == "80" ? "" : ":" + Request.ServerVariables["SERVER_PORT"];
String virtualRoot = Url.Content("~/");
destinationUrl = String.Format("http://{0}{1}{2}", Request.ServerVariables["SERVER_NAME"], port + virtualRoot, "/callback");
If you use the UrlBuilder class in the framework you can easly get around this. On the builder class if you set the port to -1 then the port number will be removed:
new UriBuilder("http://sub.example.com:15232/callback"){ Port = -1}
returns : http://sub.example.com/callback
To keep the port number on a local machine just check Request.IsLocal and don't apply -1 to the port.
I would wrap this into a extension method to keep it clean.
I see that this is an old thread. I had this issue running MVC5, on IIS 7.5, with an Apache proxy in front. Outside of the server, I would get "Empty Response", since the asp.net app gets the Url from apache with the custom port.
In order to have the app redirect to a subpath without including the "custom" port, forget the Response/Request objects, and use the Transfer method. For instance, if I want that users are automatically redirected to the login page in case they are not logged already:
if (!User.Identity.IsAuthenticated)
Server.TransferRequest("Account/Login");

Stall Internet Activity When App is Terminated

I'm messing around with the FiddlerCore and .NET and making an Internet Filter application. I'd like to "stall" or prevent Internet Activity if the app isn't running, similar to how Covenant Eyes behaves when it is terminated or logged out.
I'd like to implement a similar behavior. I tried just not closing the FiddlerCore at all, which works but the proxy can easily be removed by anyone who knows what they're doing.
Doing this:
Fiddler.FiddlerApplication.Startup(8877,fcsf);
Fiddler.FiddlerApplication.BeforeRequest += new SessionStateHandler(FiddlerApplication_BeforeRequest);
Console.ReadLine();
and never calling Fiddler.FiddlerApplication.Shutdown(); works, as mentioned (HTTP[s] connections fail), but connectivity is easily restored by removing that proxy.
I tried setting FiddlerCore to not be the system proxy (using: FiddlerCoreStartupFlags fcsf = FiddlerCoreStartupFlags.Default;
fcsf = (fcsf & ~FiddlerCoreStartupFlags.RegisterAsSystemProxy); ) but it still seemed to setup a proxy.
Basically, I'd like to hang connectivity when the app stops running, and restore it when it loads back up. Any ideas? Lemme know if i need to provide any more information. Thanks!
I'm pretty sure you can't do this. Fiddler is just a proxy, and Windows allows users to change their proxy settings.

msxml3.dll error '800c0005'

Really weird problem, I have just moved all our sites to a new Win2008 64bit server with IIS7 (Was on a Win2003 IIS6) and have started having problems with PayPal Pro / PayFlow.
A few of these websites are stores with SSL's and use PayPal Pro to process the payment - Since the move, intermittently I am getting errors like.
msxml3.dll error '800c0005' The
system cannot locate the resource
specified.
Where it seems I cannot connect resolve the PayPal URL to post the data to, as I say this has only started happening since we are on this new server. And what is even more annoying is that its completely intermittent!! Works fine for hours then will throw this error over and over then will be fine again, it effects both the Classic ASP and ASP.NET C# sites using PayPal??
Here is a log file entry if that helps?
2010-07-05 11:34:07 80.100.200.155
POST /scripts/60_Pay.asp
|297|800c0005|The_system_cannot_locate_the_resource_specified.__
443 - 92.8.25.196
Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.0;+WOW64;+Sky+Broadband;+GTB6.5;+SLCC1;+.NET+CLR+2.0.50727;+Media+Center+PC+5.0;+.NET+CLR+3.5.21022;+.NET+CLR+3.5.30729;+MDDC;+.NET+CLR+3.0.30729)
500 0 0 1907
Anyone have any ideas on what could be causing this? I was wondering if there was a way to increase the length of time it will wait to try and resolve from the external URL?
Any help would be GREATLY appreciated
Try setting the application pool that you are running this under to run in 32 bit mode and restart IIS. This will at least remove one variable.
Next you should check to see if you can write a very simple asp page that instantiates the xmlhttp object and tries to load a URL to make sure you don't have a network configuration that is preventing the new machine from reaching PayPal's servers (but which allowed the old machine to do so). This could be on your side, or their side.
Finally, are you able to run the code under a debugger on the server so you can figure out what line the error is happening on?

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