gssapi.names — Python-GSSAPI 1.6.9 documentation

# Source code for gssapi.names

    import six

    from gssapi.raw import names as rname
    from gssapi.raw import NameType
    from gssapi.raw import named_tuples as tuples
    from gssapi import _utils

    if six.PY2:
        from collections import MutableMapping, Iterable
    else:
        from collections.abc import MutableMapping, Iterable

    rname_rfc6680 = _utils.import_gssapi_extension('rfc6680')
    rname_rfc6680_comp_oid = _utils.import_gssapi_extension('rfc6680_comp_oid')

    class Name(rname.Name):
        """A GSSAPI Name

        This class represents a GSSAPI name which may be used with and/or returned
        by other GSSAPI methods.

        It inherits from the low-level GSSAPI :class:`~gssapi.raw.names.Name`
        class, and thus may used with both low-level and high-level API methods.

        This class may be pickled and unpickled, as well as copied.

        The :func:`str` and :func:`bytes` methods may be used to retrieve the
        text of the name.

        Note:
            Name strings will be automatically converted to and from unicode
            strings as appropriate.  If a method is listed as returning a
            :class:`str` object, it will return a unicode string.

            The encoding used will be python-gssapi's current encoding, which
            defaults to UTF-8.
        """

        __slots__ = ('_attr_obj')

        def __new__(cls, base=None, name_type=None, token=None,
                    composite=False):
            if token is not None:
                if composite:
                    if rname_rfc6680 is None:
                        raise NotImplementedError(
                            "Your GSSAPI implementation does not support RFC 6680 "
                            "(the GSSAPI naming extensions)")

                    if rname_rfc6680_comp_oid is not None:
                        base_name = rname.import_name(token,
                                                      NameType.composite_export)
                        displ_name = rname.display_name(base_name, name_type=True)
                        if displ_name.name_type == NameType.composite_export:
                            # NB(directxman12): there's a bug in MIT krb5 <= 1.13
                            # where GSS_C_NT_COMPOSITE_EXPORT doesn't trigger
                            # immediate import logic.  However, we can just use
                            # the normal GSS_C_NT_EXPORT_NAME in this case.
                            base_name = rname.import_name(token, NameType.export)
                    else:
                        # NB(directxman12): some older versions of MIT krb5 don't
                        # have support for the GSS_C_NT_COMPOSITE_EXPORT, but do
                        # support composite tokens via GSS_C_NT_EXPORT_NAME.
                        base_name = rname.import_name(token, NameType.export)
                else:
                    base_name = rname.import_name(token, NameType.export)
            elif isinstance(base, rname.Name):
                base_name = base
            else:
                if isinstance(base, six.text_type):
                    base = base.encode(_utils._get_encoding())

                base_name = rname.import_name(base, name_type)

            return super(Name, cls).__new__(cls, base_name)

        def __init__(self, base=None, name_type=None, token=None, composite=False):
            """
            The constructor can be used to "import" a name from a human readable
            representation, or from a token, and can also be used to convert a
            low-level :class:`gssapi.raw.names.Name` object into a high-level
            object.

            If a :class:`~gssapi.raw.names.Name` object from the low-level API
            is passed as the `base` argument, it will be converted into a
            high-level object.

            If the `token` argument is used, the name will be imported using
            the token.  If the token was exported as a composite token,
            pass `composite=True`.

            Otherwise, a new name will be created, using the `base` argument as
            the human-readable string and the `name_type` argument to denote the
            name type.

            Raises:
                BadNameTypeError
                BadNameError
                BadMechanismError
            """

            if rname_rfc6680 is not None:
                self._attr_obj = _NameAttributeMapping(self)
            else:
                self._attr_obj = None

        def __str__(self):
            if issubclass(str, six.text_type):
                # Python 3 -- we should return unicode
                return bytes(self).decode(_utils._get_encoding())
            else:
                # Python 2 -- we should return a string
                return self.__bytes__()

        def __unicode__(self):
            # Python 2 -- someone asked for unicode
            return self.__bytes__().decode(_utils._get_encoding())

        def __bytes__(self):
            # Python 3 -- someone asked for bytes
            return rname.display_name(self, name_type=False).name

        def display_as(self, name_type):
            """
            Display this name as the given name type.

            This method attempts to display the current :class:`Name`
            using the syntax of the given :class:`NameType`, if possible.

            Warning:

                In MIT krb5 versions below 1.13.3, this method can segfault if
                the name was not *originally* created with a `name_type` that was
                not ``None`` (even in cases when a ``name_type``
                is later "added", such as via :meth:`canonicalize`).
                **Do not use this method unless you are sure the above
                conditions can never happen in your code.**

            Warning:

                In addition to the above warning, current versions of MIT krb5 do
                not actually fully implement this method, and it may return
                incorrect results in the case of canonicalized names.

            :requires-ext:`rfc6680`

            Args:
                name_type (OID): the :class:`NameType` to use to display the given
                    name

            Returns:
                str: the displayed name

            Raises:
                OperationUnavailableError
            """

            if rname_rfc6680 is None:
                raise NotImplementedError("Your GSSAPI implementation does not "
                                          "support RFC 6680 (the GSSAPI naming "
                                          "extensions)")
            return rname_rfc6680.display_name_ext(self, name_type).decode(
                _utils._get_encoding())

        @property
        def name_type(self):
            """The :class:`NameType` of this name"""
            return rname.display_name(self, name_type=True).name_type

        def __eq__(self, other):
            if not isinstance(other, rname.Name):
                # maybe something else can compare this
                # to other classes, but we certainly can't
                return NotImplemented
            else:
                return rname.compare_name(self, other)

        def __ne__(self, other):
            return not self.__eq__(other)

        def __repr__(self):
            disp_res = rname.display_name(self, name_type=True)
            return "Name({name}, {name_type})".format(name=disp_res.name,
                                                      name_type=disp_res.name_type)

        def export(self, composite=False):
            """Export this name as a token.

            This method exports the name into a byte string which can then be
            imported by using the `token` argument of the constructor.

            Args:
                composite (bool): whether or not use to a composite token --
                    :requires-ext:`rfc6680`

            Returns:
                bytes: the exported name in token form

            Raises:
                MechanismNameRequiredError
                BadNameTypeError
                BadNameError
            """

            if composite:
                if rname_rfc6680 is None:
                    raise NotImplementedError("Your GSSAPI implementation does "
                                              "not support RFC 6680 (the GSSAPI "
                                              "naming extensions)")

                return rname_rfc6680.export_name_composite(self)
            else:
                return rname.export_name(self)

        def canonicalize(self, mech):
            """Canonicalize a name with respect to a mechanism.

            This method returns a new :class:`Name` that is canonicalized according
            to the given mechanism.

            Args:
                mech (OID): the :class:`MechType` to use

            Returns:
                Name: the canonicalized name

            Raises:
                BadMechanismError
                BadNameTypeError
                BadNameError
            """

            return type(self)(rname.canonicalize_name(self, mech))

        def __copy__(self):
            return type(self)(rname.duplicate_name(self))

        def __deepcopy__(self, memo):
            return type(self)(rname.duplicate_name(self))

        def _inquire(self, **kwargs):
            """Inspect this name for information.

            This method inspects the name for information.

            If no keyword arguments are passed, all available information
            is returned.  Otherwise, only the keyword arguments that
            are passed and set to `True` are returned.

            Args:
                mech_name (bool): get whether this is a mechanism name,
                    and, if so, the associated mechanism
                attrs (bool): get the attributes names for this name

            Returns:
                InquireNameResult: the results of the inquiry, with unused
                    fields set to None

            Raises:
                GSSError
            """

            if rname_rfc6680 is None:
                raise NotImplementedError("Your GSSAPI implementation does not "
                                          "support RFC 6680 (the GSSAPI naming "
                                          "extensions)")

            if not kwargs:
                default_val = True
            else:
                default_val = False

            attrs = kwargs.get('attrs', default_val)
            mech_name = kwargs.get('mech_name', default_val)

            return rname_rfc6680.inquire_name(self, mech_name=mech_name,
                                              attrs=attrs)

        @property
        def is_mech_name(self):
            """Whether or not this name is a mechanism name
            (:requires-ext:`rfc6680`)
            """
            return self._inquire(mech_name=True).is_mech_name

        @property
        def mech(self):
            """The mechanism associated with this name (:requires-ext:`rfc6680`)
            """
            return self._inquire(mech_name=True).mech

        @property
        def attributes(self):
            """The attributes of this name (:requires-ext:`rfc6680`)

            The attributes are presenting in the form of a
            :class:`~collections.MutableMapping` (a dict-like object).

            Retrieved values will always be in the form of :class:`frozensets`.

            When assigning values, if iterables are used, they be considered to be
            the set of values for the given attribute.  If a non-iterable is used,
            it will be considered a single value, and automatically wrapped in an
            iterable.

            Note:
                String types (includes :class:`bytes`) are not considered to
                be iterables in this case.
            """
            if self._attr_obj is None:
                raise NotImplementedError("Your GSSAPI implementation does not "
                                          "support RFC 6680 (the GSSAPI naming "
                                          "extensions)")

            return self._attr_obj

    class _NameAttributeMapping(MutableMapping):

        """Provides dict-like access to RFC 6680 Name attributes."""
        def __init__(self, name):
            self._name = name

        def __getitem__(self, key):
            if isinstance(key, six.text_type):
                key = key.encode(_utils._get_encoding())

            res = rname_rfc6680.get_name_attribute(self._name, key)
            return tuples.GetNameAttributeResult(frozenset(res.values),
                                                 frozenset(res.display_values),
                                                 res.authenticated,
                                                 res.complete)

        def __setitem__(self, key, value):
            if isinstance(key, six.text_type):
                key = key.encode(_utils._get_encoding())

            rname_rfc6680.delete_name_attribute(self._name, key)

            if isinstance(value, tuples.GetNameAttributeResult):
                complete = value.complete
                value = value.values
            elif isinstance(value, tuple) and len(value) == 2:
                complete = value[1]
                value = value[0]
            else:
                complete = False

            if (isinstance(value, (six.string_types, bytes)) or
                    not isinstance(value, Iterable)):
                # NB(directxman12): this allows us to easily assign a single
                # value, since that's a common case
                value = [value]

                rname_rfc6680.set_name_attribute(self._name, key, value,
                                                 complete=complete)

        def __delitem__(self, key):
            if isinstance(key, six.text_type):
                key = key.encode(_utils._get_encoding())

            rname_rfc6680.delete_name_attribute(self._name, key)

        def __iter__(self):
            return iter(self._name._inquire(attrs=True).attrs)

        def __len__(self):
            return len(self._name._inquire(attrs=True).attrs)