How to allow all https regardless of validity in .NET Core HttpClient?

Question

I am creating a web API in .NET Core. To debug it locally, I have created a console application that connects to my API. I am debugging in Linux.

When connecting to my local URL at https://localhost:5001/, my console application is throwing an AuthenticationException (The remote certificate is invalid according to the validation procedure).

I have tried to circumvent this in two ways:

1. Have added ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true; but it has no effect.

2. I have run dotnet dev-certs https --trust. Now my web browser doesn't complain anymore, which is nice, but my console application is still throwing the exception. Have tried rebooting.

How can I make .NET Core trust my localhost server? Or ignore the certificate validity?

Answer 1

Use the sample below from here

var httpClientHandler = new HttpClientHandler();
// Return `true` to allow certificates that are untrusted/invalid
httpClientHandler.ServerCertificateCustomValidationCallback = 
    HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
var httpClient = new HttpClient(httpClientHandler);

Answer 2

I found the solution:

var httpClientHandler = new HttpClientHandler();

httpClientHandler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) => true; // DEBUGGING ONLY

var httpClient = new HttpClient(httpClientHandler);

Although it is still unclear to me why the certificate is not considered valid after running dotnet dev-certs https --trust.