ASP.NET Core — Localhost Environment Certificate Not Trust Issue

Problem

In ASP.NET Core, when we create a default App or API project, it will enable SSL and automatically redirect from HTTP to HTTPS.

Here are the settings how it works:

• In Startup.cs, it calls app.UseHttpsRedirection() for redirecting HTTP to HTTPS

• In launchSettings.json, it uses “https://localhost:5001;http://localhost:5000"

It is great to always to use SSL even on local development environment, but it has some certificate issue,

If you just access the URL via browsers, you may be able to skip this error. But when you call API via C# code, then you will have certificate issue.

Solution

dotnet core has a really great tool call dev-certs, which can solve this issue easily.

Check the help of dotnet dev-certs

dotnet dev-certs https --help

Trust the HTTPS development certificate

dotnet dev-certs https --trust

Then your problem will be solved!!