How can I get the signature of an X509Certificate2 object using C#?

Question

I need to get the signature and the algorithm used to create that signature out of a certificate with C#.

Can I do that? If yes, how?

Answer 1

I am developing now application with similar functionality. And I'm really dissapointed why Microsoft didn't add property Signature to X509Certificate2 class

I know how to do that via bouncycastle

Take it from there http://www.bouncycastle.org/csharp/

Then add code

using System;
using System.Security.Cryptography.X509Certificates;
using bcrypto = Org.BouncyCastle.X509;

.

var cert = new X509Certificate2("c:\\temp\\0c50000343119659.cer");
var certParser = new bcrypto.X509CertificateParser();
var privateCertBouncy = certParser.ReadCertificate(cert.GetRawCertData());
var xx = privateCertBouncy.GetSignature();
Array.Reverse(xx);
//Signature
Console.WriteLine(BitConverter.ToString(xx));
//algorithm
Console.WriteLine(privateCertBouncy.SigAlgName);
Console.ReadLine();