CertificateUtil

private static X509Certificate2 GetCertificate(string thumbprint)
{
    return CertificateUtil.FindCertificate(StoreLocation.CurrentUser, StoreName.My, X509FindType.FindByThumbprint, thumbprint, isValid: false);
}


    public static class CertificateUtil
    {
        public static X509Certificate2 FindCertificate(StoreLocation location, StoreName name, X509FindType findType, object value, bool isValid = true)
        {
            var store = new X509Store(name, location);
            try
            {
                store.Open(OpenFlags.ReadOnly);

                if (findType == X509FindType.FindByThumbprint)
                {
                    var thumbprint = value.ToString().Trim().Replace(" ", "");

                    foreach (var cert in store.Certificates)
                    {
                        if (string.Equals(cert.Thumbprint, thumbprint, StringComparison.OrdinalIgnoreCase) || string.Equals(cert.Thumbprint, thumbprint, StringComparison.InvariantCultureIgnoreCase))
                        {
                            return cert;
                        }
                    }
                }
                if (findType == X509FindType.FindBySerialNumber)
                {
                    var serial = value.ToString().Trim().Replace(" ", "");

                    foreach (var cert in store.Certificates)
                    {
                        if (string.Equals(cert.SerialNumber, serial, StringComparison.OrdinalIgnoreCase) || string.Equals(cert.SerialNumber, serial, StringComparison.InvariantCultureIgnoreCase))
                        {
                            return cert;
                        }
                    }
                }

                var certs = store.Certificates.Find(findType, value, isValid);

                if (certs.Count != 1)
                {
                    throw new InvalidOperationException(String.Format("Certificate not found: {0}", value));
                }

                return certs[0];
            }
            finally
            {
                store.Close();
            }
        }
    }