I've been trying to perform a GET request from Visual Studio's Android Emulator to an ASP.Net Core API running on localhost. I first read that I have to use IP 10.0.2.2 when performing the request from Android, so I have the following HTTP client code in my Android (Xamarin) App
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView (Resource.Layout.Main);
var logInbutton = FindViewById<Button>(Resource.Id.logInButton);
logInbutton.Click += OnLogInButtonClicked;
}
private async void OnLogInButtonClicked(object sender, EventArgs e)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var uri = new Uri("http://10.0.2.2:5555/api/Orders?api-version=0.9");
var response = await client.GetAsync(uri);
}
}
However, each time I attempt to run this I'm greeted with a 400 Bad Request error. I know the request is okay since I can run the same Http client code from a console app without any errors. I then read that IIS express does not accept external requests and since the Android emulator is running in a VM this could be the reason.
So I then followed the advice on this SO post but was greeted with an Invalid URI: The hostname could not be parsed error. I'm not sure how to proceed from here. Is there a solution to the Invalid URI: The hostname could not be parsed error, or should I attempt to circumvent IIS Express and run solely with kestrel for development? Would even running solely in kestrel fix this problem?
I had a similar issue.
First, let's locate the correct applicationhost.config file.
You should check this location:
[solution folder]/.vs/config/applicationhost.config
Then people advice to set up binding like this:
<binding protocol="http" bindingInformation="*:5555:*" />
It did NOT work for me. I received "Invalid URI: The hostname could not be parsed".
What did work for me is the syntax like this:
<binding protocol="http" bindingInformation=":5555:" />
Please note, port 5555 is given as example. You should use the port your server is listening to.
I ran into the same issue when attempting to connect while running through kestrel. For me it worked using this configuration for the launchsettings:
Related
I have an ASP.NET Core 6 project deployed as AWS Lambda NET6 runtime and before the upgrade from 3.1 to 6 the code below worked fine returning the remote IP address even when invoked locally.
IHttpContextAccessor.HttpContext.Connection.RemoteIpAddress.ToString()
Now when I run it locally it resolves to ::1 and I have read that this might be a problem due to localhost which is something I need to overcome since I rely upon the remote IP address.
From articles found in SO (This, This, and This) I have tried the below.
Adding the below middleware in Startup.cs
app.UseForwardedHeaders(new ForwardedHeadersOptions
{
ForwardedHeaders = ForwardedHeaders.XForwardedFor |
ForwardedHeaders.XForwardedProto
});
Also added an endpoint to check what is returned locally and the deployed AWS Lambda (works fine).
[HttpGet("ipaddress")]
public IActionResult GetRemoteIpAddress(CancellationToken cancellationToken)
{
return new JsonResult(new
{
requestContextConnection = Request.HttpContext.Connection.RemoteIpAddress.ToString(),
httpContextaccessorContextConnection = _accessor.HttpContext.Connection.RemoteIpAddress.ToString(),
getRequestIp = GetRequestIP()
});
}
Method GetRequestIP() retrieved from this answer. From the below endpoint I get the below results.
Localhost:
{
"requestContextConnection": "::1",
"httpContextaccessorContextConnection": "::1",
"getRequestIp": "::1"
}
AWS Lambda deployed:
{
"requestContextConnection": "SOME.IP.207",
"httpContextaccessorContextConnection": "SOME.IP.207",
"getRequestIp": "SOME.IP.207"
}
How can I fix the localhost issue that is not supported in Kestrel; (from my understanding); I use SDK 6.0.201.
During development, i have used Swagger on the server side of my Blazor WebAssembly App. Always launching (debug) using kestrel instead of IIS Express.
Routing worked as expected, all my component routed properly and if i manually typed /swagger, i got to the swagger page. All good.
We have deployed under IIS on our pre-prod servers, the Server side and Blazor WebAssembly App (client) work as expected and are usable, however, my /swagger url gets rewritten (I assume) to go somewhere in my App instead of letting it go to Swagger, obviously there isn't any component that answers to /swagger.
My only guess is that, when hosted on IIS, the aspnet core app takes care of telling IIS what to rewrite and how (similar to the configs that could be provided thru a web.config for a "Standalone" deployment.)
I can't find how to specify exceptions, I've been following the doc at
https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/blazor/webassembly?view=aspnetcore-3.1#iis
Any idea how i could add an exception for /swagger ?
EDIT:
Turns out it works without issues in Chrome, only Firefox has the unwanted behavior. If i clear my cache, or use Incognito mode, the issue does not happen in Firefox. So, it seems that Firefox caches some stuff and tries to send my URL input to the Blazor Wasm instead of going thru to the server. I will debug some more with the dev tools and fiddler open to try and figure it out, will report back.
Turns out there this is part of the service-worker.js file that is published. It is different in dev than what gets published (which makes sense).
During my debugging i was able to reproduce the issue on all browsers (Edge, Chrome and Firefox), regardless of being in Incognito/Private mode or not.
Once the service-worker is running, it handles serving requests from cache/index.html of the Blazor WebAssembly app.
If you go into your Blazor WebAssembly Client "wwwroot" folder, you'll find a service-worker.js and a service-worker.published.js. In the service-worker.published.js, you will find a function that looks like this :
async function onFetch(event) {
let cachedResponse = null;
if (event.request.method === 'GET') {
// For all navigation requests, try to serve index.html from cache
// If you need some URLs to be server-rendered, edit the following check to exclude those URLs
const shouldServeIndexHtml = event.request.mode === 'navigate'
&& !event.request.url.includes('/connect/')
&& !event.request.url.includes('/Identity/');
const request = shouldServeIndexHtml ? 'index.html' : event.request;
const cache = await caches.open(cacheName);
cachedResponse = await cache.match(request);
}
return cachedResponse || fetch(event.request);
}
Simply following the instructions found in the code comments is gonna fix the issue. So we ended up adding an exclusion for "/swagger" like so :
&& !event.request.url.includes('/swagger')
Hopefully this post is useful for people who are gonna want to serve things outside of the service worker, not only Swagger.
Do you have UseSwagger first in your Startup.Configure method?
public static void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseSwagger();
app.UseSwaggerUI(c =>
c.SwaggerEndpoint("/swagger/v1/swagger.json", "YourAppName V1")
);
In Startup.ConfigureServices I have the Swagger code last.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddSwaggerGen(c =>
c.SwaggerDoc(
name: "v1",
info: new OpenApiInfo
{
Title = "YourAppName",
Version = "V1",
}));
}
This is working just fine for us.
Note: You must navigate to https://yourdomain/swagger/index.html
I wrote a 2013/2016 VSTO app for Microsoft Word using C#. My app creates a new toolbar with buttons. One such button runs my app, which launches a basic Windows Form.
Before the user can work with my app, they need to enter information like their license code and email address. My code in turns sends a basic request to my licensing server and awaits a response.
All my code has been running just fine and now it no longer is. Now, when I run the code, I receive the following two error messages:
System.Net.WebException: 'The underlying connection was closed: An
unexpected error occurred on a send.' Inner Exception: IOException:
Unable to read data from the transport connection: An existing
connection was forcibly closed by the remote host.
and
System.Net.WebException: 'The underlying connection was closed: An
unexpected error occurred on a send.' Inner Exception:
SocketException: An existing connection was forcibly closed by the
remote host
I decided to run the code using a standard console app to see if I received the same error message, and sure enough, it worked great! Now I am wondering if Word or the Microsoft VSTO technology is blocking my app from accessing my server.
Here is the code in VSTO that does not work
Note 1: Created a basic 2013/2016 C# VSTO add-in, added a toolbar, and added
Note 2: Added a reference to System.Web.
Note 3: Modified the website link and the query strings as I did not want to publish them on this public forum.
using System;
using Microsoft.Office.Tools.Ribbon;
using System.Web;
using System.Net;
namespace WordAddIn3
{
public partial class Ribbon1
{
private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
{
}
private void button1_Click(object sender, RibbonControlEventArgs e)
{
// Attempt to activate the product using the licensing server on the website.
Console.WriteLine("** ActivateLicense");
//build the url to call the website's software licensing component.
var builder = new UriBuilder("https://validwebsite.com");
builder.Port = -1;
//build the query string.
var query = HttpUtility.ParseQueryString(builder.Query);
query["license_key"] = "validactivationcdode";
query["product_id"] = "validproductid";
query["email"] = "validemailaddress";
builder.Query = query.ToString();
string url = builder.ToString();
Console.WriteLine("activation request:");
Console.WriteLine(url); //display the REST endpoint.
//make the synchronous call to the web service.
var syncClient = new WebClient();
var responseStream = syncClient.DownloadString(url);
Console.WriteLine("Response stream:");
Console.WriteLine(responseStream); //display the server json response.
}
}
}
Here is what is pretty much the same exact code in a console app that does work
Note 1: Created a basic C# console app.
Note 2: Added a reference to System.Web.
Note 3: Modified the website link and the query strings as I did not want to publish them on this public forum. You will receive an error, but that is due to the sample website not having a licensing server.
using System;
using System.Net;
using System.Web;
namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
// Attempt to activate the product using the licensing server on the website.
Console.WriteLine("** ActivateLicense");
//build the url to call the website's software licensing component.
var builder = new UriBuilder("https://validwebsite.com");
builder.Port = -1;
//build the query string.
var query = HttpUtility.ParseQueryString(builder.Query);
query["license_key"] = "validactivationcdode";
query["product_id"] = "validproductid";
query["email"] = "validemailaddress";
builder.Query = query.ToString();
string url = builder.ToString();
Console.WriteLine("activation request:");
Console.WriteLine(url); //display the REST endpoint.
//make the synchronous call to the web service.
var syncClient = new WebClient();
var responseStream = syncClient.DownloadString(url);
Console.WriteLine("Response stream:");
Console.WriteLine(responseStream); //display the server json response.
Console.ReadKey();
}
}
}
Can you help me determine why the code is no longer working in the add-in where it did before (with no code changes)?
I read a lot online and there seem to be too many reasons why this might happen. As an FYI, the website with the licensing server is running. It is (and always has been) a little slow, but when running the code with VSTO, the response is immediate (suggesting no timeout). The Console code runs and there is never a timeout.. I always get a response from the licensing server.
On another thread for a similar problem, someone recommended running WireShark. I am not really familiar with the product, but during my working console run, I received no error messages and instead I got messages like these:
Standard query 0x626a AAAA mywebsite.com
and
Standard query response 0x626a AAAA mywebsite.com
However, if I run the same code in VSTO, I get additional messages that are errors (this one shows up twice):
TCP 60 443 → 50308 [RST, ACK] Seq=1 Ack=125 Win=32768 Len=0
I've heard about Google's plan of modernizing OAuth interactions described here: https://developers.googleblog.com/2016/08/modernizing-oauth-interactions-in-native-apps.html
Then I was looking at the sample desktop application for Windows found here: https://github.com/googlesamples/oauth-apps-for-windows/tree/master/OAuthDesktopApp.
It's pretty simple and it was working, but once I started Visual Studio without elevated privileges (as a non-admin), I experienced that the HttpListener was not able to start because of the following error: "Access Denied".
It turned out that starting an HttpListener at the loopback address (127.0.0.1) is not possible without admin rights. However trying localhost instead of 127.0.0.1 lead to success.
I found that there is a specific command that allows HttpListener to start at the given address (and port):
netsh http add urlacl url=http://+:80/MyUri user=DOMAIN\user
But it also can be only executed with admin rights, so it's not an option.
Still localhost seems to be the best shot but OAuth 2.0 for Mobile & Desktop Apps states the following regarding this section:
See the redirect_uri parameter definition for more information about the loopback IP address. It is also possible to use localhost in place of the loopback IP, but this may cause issues with client firewalls. Most, but not all, firewalls allow loopback communication.
This is why I'm a bit suspicious to use localhost. So I'm wondering what is the recommended way of Google in this case, as I'm not intending to run our application as administrator just for this reason.
Any ideas?
You can use TcpListener for instance instead of HttpListener. It does not need elevation to listen.
The following is a modified excerpt of this sample:
https://github.com/googlesamples/oauth-apps-for-windows/tree/master/OAuthDesktopApp
// Generates state and PKCE values.
string state = randomDataBase64url(32);
string code_verifier = randomDataBase64url(32);
string code_challenge = base64urlencodeNoPadding(sha256(code_verifier));
const string code_challenge_method = "S256";
// Creates a redirect URI using an available port on the loopback address.
var listener = new TcpListener(IPAddress.Loopback, 0);
listener.Start();
string redirectURI = string.Format("http://{0}:{1}/", IPAddress.Loopback, ((IPEndPoint)listener.LocalEndpoint).Port);
output("redirect URI: " + redirectURI);
// Creates the OAuth 2.0 authorization request.
string authorizationRequest = string.Format("{0}?response_type=code&scope=openid%20profile&redirect_uri={1}&client_id={2}&state={3}&code_challenge={4}&code_challenge_method={5}",
authorizationEndpoint,
System.Uri.EscapeDataString(redirectURI),
clientID,
state,
code_challenge,
code_challenge_method);
// Opens request in the browser.
System.Diagnostics.Process.Start(authorizationRequest);
// Waits for the OAuth authorization response.
var client = await listener.AcceptTcpClientAsync();
// Read response.
var response = ReadString(client);
// Brings this app back to the foreground.
this.Activate();
// Sends an HTTP response to the browser.
WriteStringAsync(client, "<html><head><meta http-equiv='refresh' content='10;url=https://google.com'></head><body>Please close this window and return to the app.</body></html>").ContinueWith(t =>
{
client.Dispose();
listener.Stop();
Console.WriteLine("HTTP server stopped.");
});
// TODO: Check the response here to get the authorization code and verify the code challenge
The read and write methods being:
private string ReadString(TcpClient client)
{
var readBuffer = new byte[client.ReceiveBufferSize];
string fullServerReply = null;
using (var inStream = new MemoryStream())
{
var stream = client.GetStream();
while (stream.DataAvailable)
{
var numberOfBytesRead = stream.Read(readBuffer, 0, readBuffer.Length);
if (numberOfBytesRead <= 0)
break;
inStream.Write(readBuffer, 0, numberOfBytesRead);
}
fullServerReply = Encoding.UTF8.GetString(inStream.ToArray());
}
return fullServerReply;
}
private Task WriteStringAsync(TcpClient client, string str)
{
return Task.Run(() =>
{
using (var writer = new StreamWriter(client.GetStream(), Encoding.UTF8))
{
writer.Write("HTTP/1.0 200 OK");
writer.Write(Environment.NewLine);
writer.Write("Content-Type: text/html; charset=UTF-8");
writer.Write(Environment.NewLine);
writer.Write("Content-Length: " + str.Length);
writer.Write(Environment.NewLine);
writer.Write(Environment.NewLine);
writer.Write(str);
}
});
}
By default there is a URL pattern http://+:80/Temporary_Listen_Addresses/ which is allowed for all users (\Everyone)
You can use this as a prefix for your listener. More generally (to avoid collisions with other listeners) you should generate a URL under Temporary_Listen_Addresses (e.g. using a GUID) and use that as your listener prefix.
Unfortunately, a sysadmin can use netsh http to delete this entry or to restrict its usage to only certain users. Also, this does not appear to support listening for an HTTPS request as there is no corresponding ACL entry for port 443.
An admin can list all these permitted URL patterns using netsh http show urlacl as a command.
I've got an ServiceStack service running with custom authentication, this runs fine from the browser and through a Windows console program.
I'm now trying to get a simple Xamarin Android program to authenticate but whatever I try it crashes with an Exception without any further explanation. The code I am using stops at the line with 'var authResponse', I'm using the 4.0.44 ServiceStack packages and the lastest stable Xamarin from inside VS2015.
protected override void OnCreate (Bundle bundle)
{
base.OnCreate (bundle);
// Set our view from the "main" layout resource
SetContentView (Resource.Layout.Main);
// servicestack
var client = new JsonServiceClient("http://10.0.2.2:8080");
var authResponse = client.Get<AuthenticateResponse>( new Authenticate
{
UserName = "Willem",
Password = "secret",
RememberMe = true
});
Any pointers to what/where I should look?
tia
If this is a self-hosted Service you would need to register the HttpListener AppHost to accept requests from different hosts by listening on a host wildcard, e.g:
appHost.Start("http://*:8080/");