How do I read the digital signature information from a signed .Net assembly?

Question

I am writing an assembly information application to be used in our software build process and am trying to read the digital signature information from a signed .Net assembly.

I want to do in my C# code what Windows Explorer can do by right-clicking a signed assembly and selecting the "Digital Signatures" tab and then clicking the Details button. e.g.

Has anyone got an idea how to do this programmatically in C#? I am currently using the Mono Cecil library to get the rest of the information from the assembly. Your help will be most appreciated.

Suppositive

What you show is Authenticode signature, applicable to all PE files. There also exists strongnaming, .NET-specific signature format. Strongnaming is done using a keypair, not a certificate, consequently you can't extract any useful information from the strongnamed assembly. Doing search for Authenticode on StackOverflow will give you plenty of useful information. – Felicefelicia

Possibly related questions. – Perversion

possible duplicate of How do I read the public key from a signed C# exe – Dinny

That did the trick, the X509Certificate.CreateFromSignedFile(exe) works like a charm. However, it raises an exception rather null as shown in the "How do I read the public key from a signed C# exe" link. – Suppositive

Answer 1

The Mono project provides source code for both signcode and chktrust that you can re-use inside your own application (open source, MIT X11 licensed).

Both use Mono.Security.dll assembly (which works under Windows, not just Linux and OSX) and include a quite complete Authenticode support.

Guff

Answer 2

From this response :

SignCode (for .Net 1.0 and 1.1) uses Authenticode signing, which as far as I'm aware, lacks a .Net Framework managed interface.

Hopefully, it's looks like that some Nuget package implement it:

• https://github.com/vcsjones/AuthenticodeExaminer
• https://github.com/vcsjones/AuthenticodeLint
• https://www.nuget.org/packages/CodeFluentRuntimeClient/

Pyrene