mirror of
https://github.com/theupdateframework/python-tuf
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5d71aab9ec
The pylint warning W0703:broad-except was raised only when six was used and python 2 was still supported. The warning is no longer raised, the exceptions are handled/raised correctly and the disabling can be removed. Signed-off-by: Teodora Sechkova <tsechkova@vmware.com>
89 lines
2.8 KiB
Python
89 lines
2.8 KiB
Python
# Copyright New York University and the TUF contributors
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# SPDX-License-Identifier: MIT OR Apache-2.0
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"""TUF role metadata JSON serialization and deserialization.
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This module provides concrete implementations to serialize and deserialize TUF
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role metadata to and from the JSON wireline format for transportation, and
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to serialize the 'signed' part of TUF role metadata to the OLPC Canonical JSON
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format for signature generation and verification.
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"""
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import json
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from securesystemslib.formats import encode_canonical
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# pylint: disable=cyclic-import
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# ... to allow de/serializing Metadata and Signed objects here, while also
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# creating default de/serializers there (see metadata local scope imports).
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# NOTE: A less desirable alternative would be to add more abstraction layers.
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from tuf.api.metadata import Metadata, Signed
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from tuf.api.serialization import (
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DeserializationError,
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MetadataDeserializer,
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MetadataSerializer,
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SerializationError,
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SignedSerializer,
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)
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class JSONDeserializer(MetadataDeserializer):
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"""Provides JSON to Metadata deserialize method."""
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def deserialize(self, raw_data: bytes) -> Metadata:
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"""Deserialize utf-8 encoded JSON bytes into Metadata object."""
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try:
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json_dict = json.loads(raw_data.decode("utf-8"))
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metadata_obj = Metadata.from_dict(json_dict)
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except Exception as e:
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raise DeserializationError from e
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return metadata_obj
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class JSONSerializer(MetadataSerializer):
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"""Provides Metadata to JSON serialize method.
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Attributes:
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compact: A boolean indicating if the JSON bytes generated in
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'serialize' should be compact by excluding whitespace.
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"""
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def __init__(self, compact: bool = False) -> None:
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self.compact = compact
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def serialize(self, metadata_obj: Metadata) -> bytes:
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"""Serialize Metadata object into utf-8 encoded JSON bytes."""
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try:
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indent = None if self.compact else 1
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separators = (",", ":") if self.compact else (",", ": ")
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json_bytes = json.dumps(
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metadata_obj.to_dict(),
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indent=indent,
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separators=separators,
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sort_keys=True,
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).encode("utf-8")
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except Exception as e:
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raise SerializationError from e
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return json_bytes
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class CanonicalJSONSerializer(SignedSerializer):
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"""Provides Signed to OLPC Canonical JSON serialize method."""
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def serialize(self, signed_obj: Signed) -> bytes:
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"""Serialize Signed object into utf-8 encoded OLPC Canonical JSON
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bytes.
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"""
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try:
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signed_dict = signed_obj.to_dict()
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canonical_bytes = encode_canonical(signed_dict).encode("utf-8")
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except Exception as e:
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raise SerializationError from e
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return canonical_bytes
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