def primitive(self, primitive_class: Type[P]) -> P:
"""Returns a wrapped primitive from this KeysetHandle.
Uses the KeyManager and the PrimitiveWrapper objects in the global
registry.Registry
to create the primitive. This function is the most common way of creating a
primitive.
Args:
primitive_class: The class of the primitive.
Returns:
The primitive.
Raises:
tink.TinkError if creation of the primitive fails, for example if
primitive_class cannot be used with this KeysetHandle.
"""
_validate_keyset(self._keyset)
pset = primitive_set.PrimitiveSet(primitive_class)
for key in self._keyset.key:
if key.status == tink_pb2.ENABLED:
primitive = registry.Registry.primitive(
key.key_data, primitive_class)
entry = pset.add_primitive(primitive, key)
if key.key_id == self._keyset.primary_key_id:
pset.set_primary(entry)
return registry.Registry.wrap(pset)
def register_primitive_wrapper(
cls, wrapper: primitive_wrapper.PrimitiveWrapper) -> None:
"""Tries to register a PrimitiveWrapper.
Args:
wrapper: A PrimitiveWrapper object.
Raises:
Error if a different wrapper has already been registered for the same
Primitive.
"""
if (wrapper.primitive_class() in cls._wrappers and type(
cls._wrappers[wrapper.primitive_class()]) != type(wrapper)): # pylint: disable=unidiomatic-typecheck
raise tink_error.TinkError(
'A wrapper for primitive {} has already been added.'.format(
wrapper.primitive_class().__name__))
wrapped = wrapper.wrap(
pset_module.PrimitiveSet(wrapper.primitive_class()))
if not isinstance(wrapped, wrapper.primitive_class()):
raise tink_error.TinkError(
'Wrapper for primitive {} generates incompatible primitive of type {}'
.format(wrapper.primitive_class().__name__,
type(wrapped).__name__))
cls._wrappers[wrapper.primitive_class()] = wrapper
