How to dual sign a binary with Authenticode?

Question

Short question

How can I get information about multiple code signing certificates from an executable (.EXE/.DLL)?

Expected answer

Answer 1

Give Mono a try. It's able to pull all of the file's Authenticode certificates in one line!

    using Mono.Security.Authenticode;

    AuthenticodeDeformatter monoFileCert = new AuthenticodeDeformatter("System.Windows.dll");
    Console.WriteLine($"Found certificates {monoFileCert.Certificates.Count}");

https://github.com/mono/mono/blob/master/mcs/class/Mono.Security/Mono.Security.Authenticode/AuthenticodeDeformatter.cs

Usage example: https://github.com/mono/mono/blob/master/mcs/tools/security/chktrust.cs