def deserialize(serialized_material_description):
# type: (dynamodb_types.BINARY_ATTRIBUTE) -> Dict[Text, Text]
"""Deserialize a serialized material description attribute into a material description dictionary.
:param dict serialized_material_description: DynamoDB attribute value containing serialized material description.
:returns: Material description dictionary
:rtype: dict
:raises InvalidMaterialDescriptionError: if malformed version
:raises InvalidMaterialDescriptionVersionError: if unknown version is found
"""
try:
_raw_material_description = serialized_material_description[Tag.BINARY.dynamodb_tag]
material_description_bytes = io.BytesIO(_raw_material_description)
total_bytes = len(_raw_material_description)
except (TypeError, KeyError):
message = 'Invalid material description'
_LOGGER.exception(message)
raise InvalidMaterialDescriptionError(message)
# We don't currently do anything with the version, but do check to make sure it is the one we know about.
_read_version(material_description_bytes)
material_description = {}
try:
while material_description_bytes.tell() < total_bytes:
name = to_str(decode_value(material_description_bytes))
value = to_str(decode_value(material_description_bytes))
material_description[name] = value
except struct.error:
message = 'Invalid material description'
_LOGGER.exception(message)
raise InvalidMaterialDescriptionError(message)
return material_description
def encryption_materials(self, encryption_context):
# type: (EncryptionContext) -> RawEncryptionMaterials
"""Provide encryption materials.
:param EncryptionContext encryption_context: Encryption context for request
:returns: Encryption materials
:rtype: RawEncryptionMaterials
"""
initial_material, encrypted_initial_material = self._generate_initial_material(
encryption_context)
encryption_material_description = encryption_context.material_description.copy(
)
encryption_material_description.update({
_COVERED_ATTR_CTX_KEY:
_KEY_COVERAGE,
MaterialDescriptionKeys.CONTENT_KEY_WRAPPING_ALGORITHM.value:
"kms",
MaterialDescriptionKeys.CONTENT_ENCRYPTION_ALGORITHM.value:
self._content_key_info.description,
MaterialDescriptionKeys.ITEM_SIGNATURE_ALGORITHM.value:
self._signing_key_info.description,
MaterialDescriptionKeys.WRAPPED_DATA_KEY.value:
to_str(base64.b64encode(encrypted_initial_material)),
})
return RawEncryptionMaterials(
signing_key=self._mac_key(initial_material,
self._signing_key_info),
encryption_key=self._encryption_key(initial_material,
self._content_key_info),
material_description=encryption_material_description,
)
def _transform_number_value(value):
# (bytes) -> dynamodb_types.STRING
"""Transforms a serialized number value.
:param bytes value: Raw deserialized value
:rtype: dynamodb_encryption_sdk.internal.dynamodb_types.STRING
"""
raw_value = codecs.decode(value, TEXT_ENCODING)
decimal_value = Decimal(to_str(raw_value)).normalize()
return "{0:f}".format(decimal_value)
def test_to_str(data, expected_output):
test = to_str(data)
assert test == expected_output