Skip to main content

OData: attach a client certificate through Fiddler when connecting to an OData service

At a customer, we had to use a 3th party OData service. Using OData feeds in .NET is simple, but this one was a little bit harder to use because it was secured using a client certificate.

We first wanted to browse through the OData feed using LinqPad but we couldn’t find a way to configure LinqPad to add the certificate to each request.

Use Fiddler to include a client certificate with each request

We decided to follow a different route and use Fiddler to include the certificate for us. Fiddler is a web debugging proxy that can intercept all the HTTP traffic we are doing on our system.

Here are the steps you need to take:

  • Get the client certificate.
  • If you have a .pfx file including the private key, extract it and install the certificate in your personal certificate store.
  • Download and install Fiddler in case you didn’t have it.
  • Start Fiddler.
  • Go to Tools –> Fiddler Options
  • Go to the HTTPS Tab and check the checkbox next to Decrypt HTTPS traffic.
  • Fiddler will ask you to install a new root certificate, click Yes if asked for confirmation. (Installing this certificate implies a security risk, so remove it after you’re done)
  • Go to the C:\Users\{UserName}\Documents\Fiddler2 folder.
  • Copy the client certificate to this folder and rename it to ClientCertificate.cer
  • That’s it.

If you now try to connect to your OData service, Fiddler will capture the traffic, attach the client certificate and forward the request to the service.

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

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…

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.