def verifyCert(self, cert):
        """ Verifies either a Cert or an X509_Cert. """
        tbsCert = cert.tbsCertificate
        sigAlg = tbsCert.signature
        h = hash_by_oid[sigAlg.algorithm.val]
        sigVal = raw(cert.signatureValue)
        return self.verify(raw(tbsCert), sigVal, h=h, t='pkcs')