private static bool IsParent(Mono.Security.X509.X509Certificate child, Mono.Security.X509.X509Certificate parent)
{
if (child.IssuerName != parent.SubjectName)
return false;
if ( parent.RSA != null && child.VerifySignature (parent.RSA) )
return true;
if ( parent.DSA != null && child.VerifySignature (parent.DSA) )
return true;
return false;
}