def certificateOptionsFromPEMs(pemObjects, **kw):
    """
    Load a CertificateOptions from the given collection of PEM objects
    (already-loaded private keys and certificates).

    In those PEM objects, identify one private key and its corresponding
    certificate to use as the primary certificate.  Then use the rest of the
    certificates found as chain certificates.  Raise a ValueError if no
    certificate matching a private key is found.

    :return: A TLS context factory using *pemObjects*
    :rtype: `twisted.internet.ssl.CertificateOptions`_

    .. _`twisted.internet.ssl.CertificateOptions`: \
        https://twistedmatrix.com/documents/current/api/\
        twisted.internet.ssl.CertificateOptions.html
    """
    keys = [key for key in pemObjects if isinstance(key, Key)]
    if not len(keys):
        raise ValueError('Supplied PEM file(s) does *not* contain a key.')
    if len(keys) > 1:
        raise ValueError('Supplied PEM file(s) contains *more* than one key.')

    privateKey = ssl.KeyPair.load(str(keys[0]), FILETYPE_PEM)

    certs = [cert for cert in pemObjects if isinstance(cert, Certificate)]
    if not len(certs):
        raise ValueError('*At least one* certificate is required.')
    certificates = [ssl.Certificate.loadPEM(str(certPEM))
                    for certPEM in certs]

    certificatesByFingerprint = dict(
        [(certificate.getPublicKey().keyHash(), certificate)
         for certificate in certificates]
    )

    if privateKey.keyHash() not in certificatesByFingerprint:
        raise ValueError("No certificate matching {fingerprint} found.".format(
            fingerprint=privateKey.keyHash()
        ))

    primaryCertificate = certificatesByFingerprint.pop(privateKey.keyHash())

    if "dhParameters" in kw:
        warnings.warn(
            "Passing DH parameters as a keyword argument instead of a PEM "
            "object is deprecated as of pem 16.1.0.",
            DeprecationWarning
        )
    else:
        dhparams = [o for o in pemObjects if isinstance(o, DHParameters)]
        if len(dhparams) > 1:
            raise ValueError(
                "Supplied PEM file(s) contain(s) *more* than one set of DH "
                "parameters.")
        elif len(dhparams) == 1:
            kw["dhParameters"] = DiffieHellmanParameters(str(dhparams[0]))

    fakeEDHSupport = "dhParameters" in kw or not _DH_PARAMETERS_SUPPORTED
    if fakeEDHSupport:
        dhParameters = kw.pop("dhParameters")

    if _DH_PARAMETERS_SUPPORTED is False:
        warnings.warn(
            "Using pem with Twisted older than 14.0.0 is deprecated as of pem"
            " 15.0.0.  "
            "The backport of DiffieHellmanParameters will be removed.",
            DeprecationWarning
        )

    ctxFactory = ssl.CertificateOptions(
        privateKey=privateKey.original,
        certificate=primaryCertificate.original,
        extraCertChain=[chain.original
                        for chain in certificatesByFingerprint.values()],
        **kw
    )

    if fakeEDHSupport:
        return _DHParamContextFactory(ctxFactory, dhParameters)
    else:
        return ctxFactory
dataset/ETHPy150Open hynek/pem/src/pem/twisted.py/certificateOptionsFromPEMs/operator `and` -> `or`