Where can I find the ASP.NET Core 2 source code? Specifically for Microsoft.AspNetCore.Authentication.OpenIdConnect

DotNet Core is a large project spread over several repositories and groups on GitHub. DotNet Core code is available in

https://github.com/dotnet repos

while all ASP.NET Core specific code is available in

https://github.com/aspnet repos.

The source code which you are looking for is in

aspnet/Security repo.

OpenIdConnect sources are available under the following link:

aspnet/Security/src/Microsoft.AspNetCore.Authentication.OpenIdConnect/

After 2 years as this question is opened, I personally found very excellent search fatures to navigate on NET Core sourse code the official web site https://source.dot.net/

You can just search any Type of class, vars, interfaces etc and get in a second the complete source.

Hope this will help.