Skip to main content

ASP.NET Core 2.2 - SignalR Breaking changes

After a seamlessly flawless upgrade to ASP.NET Core, we got into trouble when using SignalR hubs.

In our code we were rather lazy and had allowed CORS for everything:

In ASP.NET Core 2.2 it is no longer allowed to combine AllowAnyOrigin and AllowCredentials.  When you try to use the two together, you‘ll see the following warning in the output window:

warn: Microsoft.AspNetCore.Cors.Infrastructure.CorsService

The CORS protocol does not allow specifying a wildcard (any) origin and credentials at the same time. Configure the policy by listing individual origins if credentials needs to be supported.

Problem is that this warning breaks the preflight OPTIONS check of SignalR and the client can no longer connect to the hubs.

To fix this, you have to remove the AllowAnyOrigin method and instead specify the origins explicitly(like it should be in the first place):

Labels:

Popular posts from this blog

DevToys–A swiss army knife for developers

As a developer there are a lot of small tasks you need to do as part of your coding, debugging and testing activities.  DevToys is an offline windows app that tries to help you with these tasks. Instead of using different websites you get a fully offline experience offering help for a large list of tasks. Many tools are available. Here is the current list: Converters JSON <> YAML Timestamp Number Base Cron Parser Encoders / Decoders HTML URL Base64 Text & Image GZip JWT Decoder Formatters JSON SQL XML Generators Hash (MD5, SHA1, SHA256, SHA512) UUID 1 and 4 Lorem Ipsum Checksum Text Escape / Unescape Inspector & Case Converter Regex Tester Text Comparer XML Validator Markdown Preview Graphic Color B
Read more

Help! I accidently enabled HSTS–on localhost

I ran into an issue after accidently enabling HSTS for a website on localhost. This was not an issue for the original website that was running in IIS and had a certificate configured. But when I tried to run an Angular app a little bit later on http://localhost:4200 the browser redirected me immediately to https://localhost . Whoops! That was not what I wanted in this case. To fix it, you need to go the network settings of your browser, there are available at: chrome://net-internals/#hsts edge://net-internals/#hsts brave://net-internals/#hsts Enter ‘localhost’ in the domain textbox under the Delete domain security policies section and hit Delete . That should do the trick…
Read more

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.
Read more