Skip to main content

.NET Core - Renew localhost certificate

Today when I tried to debug a .NET Core application, I got a browser warning that my localhost certificate was no longer valid.

The good news is that renewing your localhost certficate when using Kestrel is easy. You can use the built-in dotnet dev-certs command to manage a self-signed certificate.

We can first remove the existing outdated certificate by executing the following command:

dotnet dev-certs https --clean

Output:

Cleaning HTTPS development certificates from the machine. A prompt might get displayed to confirm the removal of some of the certificates.

HTTPS development certificates successfully removed from the machine.

Now we can generate a new self-signed certificate using following command:

dotnet dev-certs https –trust

Output:

Trusting the HTTPS development certificate was requested. A confirmation prompt will be displayed if the certificate was not previously trusted. Click yes on the prompt to trust the certificate.

Successfully created and trusted a new HTTPS certificate.

As a last step, you can validate the certificate by executing the following command

dotnet dev-certs https –check

Output:

A valid certificate was found: 189E61FFAD59C21110E9AD13A009B984EE5E8D5D - CN=localhost - Valid from 2024-04-22 13:11:50Z to 2025-04-22 13:11:50Z - IsHttpsDevelopmentCertificate: true - IsExportable: true

Run the command with both --check and --trust options to ensure that the certificate is not only valid but also trusted.

Remark: The steps above only work when you are running your ASP.NET Core application using Kestrel, if you are using IIS or IIS Express a different approach is needed.

More information

dotnet dev-certs command - .NET CLI | Microsoft Learn

Labels:

Popular posts from this blog

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

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...
Read more

Cleaner switch expressions with pattern matching in C#

Ever find yourself mapping multiple string values to the same result? Being a C# developer for a long time, I sometimes forget that the C# has evolved so I still dare to chain case labels or reach for a dictionary. Of course with pattern matching this is no longer necessary. With pattern matching, you can express things inline, declaratively, and with zero repetition. A small example I was working on a small script that should invoke different actions depending on the environment. As our developers were using different variations for the same environment e.g.  "tst" alongside "test" , "prd" alongside "prod" .  We asked to streamline this a long time ago, but as these things happen, we still see variations in the wild. This brought me to the following code that is a perfect example for pattern matching: The or keyword here is a logical pattern combinator , not a boolean operator. It matches if either of the specified pattern...
Read more