How to use the federation.credentials.src.trust.certificate.Keypair function in federation

def get_pubkey(self):
        m2x509 = X509.load_cert_string(self.save_to_string())
        pkey = Keypair()
        pkey.key = self.cert.get_pubkey()
        pkey.m2key = m2x509.get_pubkey()
        return pkey

# create an m2 x509 cert
        m2name = M2Crypto.X509.X509_Name()
        m2name.add_entry_by_txt(field="CN", type=0x1001, entry="junk", len=-1, loc=-1, set=0)
        m2x509 = M2Crypto.X509.X509()
        m2x509.set_pubkey(self.m2key)
        m2x509.set_serial_number(0)
        m2x509.set_issuer_name(m2name)
        m2x509.set_subject_name(m2name)
        ASN1 = M2Crypto.ASN1.ASN1_UTCTIME()
        ASN1.set_time(500)
        m2x509.set_not_before(ASN1)
        m2x509.set_not_after(ASN1)
        # x509v3 so it can have extensions
        # prob not necc since this cert itself is junk but still...
        m2x509.set_version(2)
        junk_key = Keypair(create=True)
        m2x509.sign(pkey=junk_key.get_m2_pkey(), md="sha1")

        # convert the m2 x509 cert to a pyopenssl x509
        m2pem = m2x509.as_pem()
        pyx509 = crypto.load_certificate(crypto.FILETYPE_PEM, m2pem)

        # get the pyopenssl pkey from the pyopenssl x509
        self.key = pyx509.get_pubkey()
        self.filename=filename

(ssh_f, ssh_fn) = tempfile.mkstemp()
    ssl_fn = tempfile.mktemp()
    os.write(ssh_f, key)
    os.close(ssh_f)

    cmd = keyconvert_path + " " + ssh_fn + " " + ssl_fn
    os.system(cmd)

    # this check leaves the temporary file containing the public key so
    # that it can be expected to see why it failed.
    # TODO: for production, cleanup the temporary files
    if not os.path.exists(ssl_fn):
        raise Exception, "keyconvert: generated certificate not found. keyconvert may have failed."

    k = Keypair()
    try:
        k.load_pubkey_from_file(ssl_fn)
        return k
    except Exception as e:
        raise e
    finally:
        # remove the temporary files
        if os.path.exists(ssh_fn):
            os.remove(ssh_fn)
        if os.path.exists(ssl_fn):
            os.remove(ssl_fn)

def set_pubkey(self, key):
        assert(isinstance(key, Keypair))
        self.cert.set_pubkey(key.get_openssl_pkey())