VB.NET code to find a certificate with its issuer name and display its contents – small post but helpful

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This is a small blog post but I found it handy and useful to document.

I created a test certificate with name “shmisra” and kept it in the “Personal” store in the users profile as shown below.

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I read this certificate and print its details using the code shown below.

Imports System

Imports System.Security.Cryptography

Imports System.Security.Cryptography.X509Certificates

Imports System.IO

Module Module1

Sub Main()

'Create a X509Store object.

Dim x509Store As New X509Store(StoreName.My, StoreLocation.CurrentUser)

Try

' create and open store for read-only access

            x509Store.Open(OpenFlags.ReadOnly)

' search store

Dim col As New X509Certificate2Collection

            col = x509Store.Certificates.Find(X509FindType.FindByIssuerName, "shmisra", True)

'Print to console the information contained in the certificate.

            Console.WriteLine("{0}Subject: {1}{0}", Environment.NewLine, col(0).Subject)

            Console.WriteLine("{0}Issuer: {1}{0}", Environment.NewLine, col(0).Issuer)

            Console.WriteLine("{0}Version: {1}{0}", Environment.NewLine, col(0).Version)

            Console.WriteLine("{0}Valid Date: {1}{0}", Environment.NewLine, col(0).NotBefore)

            Console.WriteLine("{0}Expiry Date: {1}{0}", Environment.NewLine, col(0).NotAfter)

            Console.WriteLine("{0}Thumbprint: {1}{0}", Environment.NewLine, col(0).Thumbprint)

            Console.WriteLine("{0}Serial Number: {1}{0}", Environment.NewLine, col(0).SerialNumber)

            Console.WriteLine("{0}Friendly Name: {1}{0}", Environment.NewLine, col(0).PublicKey.Oid.FriendlyName)

            Console.WriteLine("{0}Public Key Format: {1}{0}", Environment.NewLine, col(0).PublicKey.EncodedKeyValue.Format(True))

            Console.WriteLine("{0}Raw Data Length: {1}{0}", Environment.NewLine, col(0).RawData.Length)

            Console.WriteLine("{0}Certificate to string: {1}{0}", Environment.NewLine, col(0).ToString(True))

            Console.WriteLine("{0}Certificate to XML String: {1}{0}", Environment.NewLine, col(0).PublicKey.Key.ToXmlString(False))

Catch ex As Exception

            Console.WriteLine("An error occurred: '{0}'", ex)

Finally

            X509Store.Close()

End Try

End Sub

End Module

The X509FindType enumeration has several members so you can change the search criteria based upon your need. Say you want to search a certificate based on the serial number of the certificate. So the search code will be:

' search store

Dim col As New X509Certificate2Collection

col = x509Store.Certificates.Find(X509FindType.FindBySerialNumber, "xxxxxx", True)

‘ True is specified to allow only valid certificates to be returned from the search; otherwise specify False.

References:

· https://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509store.aspx

· https://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509findtype.aspx

· https://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509certificate2collection.find.aspx

 

-Shamik Misra