def _parse_iv(self, byte_array, off):
length = len(byte_array) - off
if length < self._iv_length:
raise exceptions.ParseError('Not enough bytes to parse IV')
self.iv = byte_array[off:off + self._iv_length]
return self._iv_length
def _parse_encryption_context(self, byte_array, off):
length = len(byte_array) - off
if length < self._encryption_context_length:
raise exceptions.ParseError(
'Not enough bytes to parse encryption context')
self._encryption_context = _EncryptionContext()
parsed_bytes = self._encryption_context.deserialize(byte_array, off)
self.encryption_context = self._encryption_context.to_dict()
if parsed_bytes != self._encryption_context_length:
raise exceptions.ParseError(
'Did not properly parse encryption context')
return self._encryption_context_length
def _parse_encrypted_data_key(self, byte_array, off):
length = len(byte_array) - off
if length < self._encrypted_data_key_length:
raise exceptions.ParseError(
'Not enough bytes to parse encrypted data key')
self.encrypted_data_key = byte_array[off:off +
self._encrypted_data_key_length]
return self._encrypted_data_key_length
def _parse_key_provider_info(self, byte_array, off):
length = len(byte_array) - off
if length < self._key_provider_info_length:
raise exceptions.ParseError(
'Not enough bytes to parse key provider info')
self.key_provider_info = byte_array[off:off +
self._key_provider_info_length]
return self._key_provider_info_length
def _parse_authentication_tag(self, byte_array, off):
length = len(byte_array) - off
if length < self._authentication_tag_length:
raise exceptions.ParseError(
'Not enough bytes to parse authentication tag')
self.authentication_tag = byte_array[off:off +
self._authentication_tag_length]
return self._authentication_tag_length
def deserialize(self, byte_array, off):
"""Loads information from ``byte_array`` into this object."""
parsed_bytes = 0
self.header = Header()
parsed_bytes += self.header.deserialize(byte_array, off + parsed_bytes)
if self.header.content_type == 2:
self.body = FrameBody(header=self.header)
parsed_bytes += self.body.deserialize(byte_array,
off + parsed_bytes)
else:
raise NotImplementedError('Non-framed content not supported yet')
if len(byte_array) - parsed_bytes > 0:
self.footer = Footer()
parsed_bytes += self.footer.deserialize(byte_array,
off + parsed_bytes)
if parsed_bytes != len(byte_array):
raise exceptions.ParseError('Did not parse all the bytes')
return parsed_bytes
def _parse_signature(self, byte_array, off):
length = len(byte_array) - off
if length < self._signature_length:
raise exceptions.ParseError('Not enough bytes to parse signature')
self.signature = byte_array[off:off + self._signature_length]
return self._signature_length