Serialization

tuf.api.serialization module provides abstract base classes and concrete implementations to serialize and deserialize TUF metadata.

Any custom de/serialization implementations should inherit from the abstract base classes defined in this module. The implementations can use the to_dict()/from_dict() implementations available in the Metadata API objects.

Metadata de/serializers are used to convert to and from wireline formats.
Signed serializers are used to canonicalize data for cryptographic signatures generation and verification.

exception DeserializationError

Error during deserialization.

add_note(): Exception.add_note(note) – add a note to the exception

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class MetadataDeserializer

Abstract base class for deserialization of Metadata objects.

abstractmethod deserialize(raw_data)

Deserialize bytes to Metadata object.

Parameters:: raw_data (bytes)
Return type:: Metadata

class MetadataSerializer

Abstract base class for serialization of Metadata objects.

abstractmethod serialize(metadata_obj)

Serialize Metadata object to bytes.

Parameters:: metadata_obj (Metadata)
Return type:: bytes

exception SerializationError

Error during serialization.

add_note(): Exception.add_note(note) – add a note to the exception

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class SignedSerializer

Abstract base class for serialization of Signed objects.

abstractmethod serialize(signed_obj)

Serialize Signed object to bytes.

Parameters:: signed_obj (Signed)
Return type:: bytes

JSON serialization

tuf.api.serialization.json module provides concrete implementations to serialize and deserialize TUF role metadata to and from the JSON wireline format for transportation, and to serialize the ‘signed’ part of TUF role metadata to the OLPC Canonical JSON format for signature generation and verification.

class CanonicalJSONSerializer

Bases: SignedSerializer

Provides Signed to OLPC Canonical JSON serialize method.

serialize(signed_obj)

Serialize Signed object into utf-8 encoded OLPC Canonical JSON bytes.

Parameters:: signed_obj (Signed)
Return type:: bytes

class JSONDeserializer

Bases: MetadataDeserializer

Provides JSON to Metadata deserialize method.

deserialize(raw_data)

Deserialize utf-8 encoded JSON bytes into Metadata object.

Parameters:: raw_data (bytes)
Return type:: Metadata

class JSONSerializer(compact=False, validate=False)

Bases: MetadataSerializer

Provides Metadata to JSON serialize method.

Parameters:

compact (bool) – A boolean indicating if the JSON bytes generated in ‘serialize’ should be compact by excluding whitespace.
validate (bool | None) – Check that the metadata object can be deserialized again without change of contents and thus find common mistakes. This validation might slow down serialization significantly.

serialize(metadata_obj)

Serialize Metadata object into utf-8 encoded JSON bytes.

Parameters:: metadata_obj (Metadata)
Return type:: bytes