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.

class MetadataDeserializer

Abstract base class for deserialization of Metadata objects.

abstract 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.

abstract serialize(metadata_obj)

Serialize Metadata object to bytes.

Parameters:

metadata_obj (Metadata) –

Return type:

bytes

exception SerializationError

Error during serialization.

class SignedSerializer

Abstract base class for serialization of Signed objects.

abstract 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