At the least it should be made clear in the documentation that the
hostname is not checked against the commonName nor the subjectAltName
fields of the server certificate. And add some sample code to the
documentation for doing a simple check. Something like this, to illustrate:

def get_subjectAltName(cert):
        if not cert.has_key('subjectAltName'):
                return []
        ret = []
        for rdn in cert['subjectAltName']:
                if rdn[0].lower() == 'dns' or rdn[0][:2].lower() == 'ip':
                        ret.append(rdn[1])
        return ret

def get_commonName(cert):
        if not cert.has_key('subject'):
                return []
        ret = []
        for rdn in cert['subject']:
                if rdn[0][0].lower() == 'commonname':
                        ret.append(rdn[0][1])
        return ret


def verify_hostname(cert, host):
        cn = get_commonName(cert)
        san = get_subjectAltName(cert)
        return (host in cn) or (host in san)