old_contents: # Licensed to Tomaz Muraus under one or more
  # contributor license agreements.  See the NOTICE file distributed with
  # this work for additional information regarding copyright ownership.
  # Tomaz muraus licenses this file to You under the Apache License, Version 2.0
  # (the "License"); you may not use this file except in compliance with
  # the License.  You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  class HybridCryptoMixin(object):
      block_size = 16
      header_size = 4  # Encrypted message header size (in bytes)
      long_message_threshold = (2048 / 8) - 41  # When message can't be encryted
                                                # using only PKC and hybrid mode
                                                # is used
      aes_key_size = 256 / 8  # Size of the generated AES key (in bytes)
      delimiter = ':'
  
      def _pad_data(self, data):
          """
          Pad provided data using PKCS#7.
          """
          # Data needs to be padded with at least 1 byte
          pad_len = self.block_size - (len(data) % self.block_size)
          pad_byte = chr(pad_len)
          pad_value = pad_len * pad_byte
  
          padded_data = data + pad_value
          return padded_data
  
      def _unpad_data(self, data):
          """
          Unpad provided data using PKCS#7.
          """
          pad_len = ord(data[-1])
  
          if pad_len > len(data):
              raise ValueError('Corrupted data')
  
          unpadded_data = data[:-pad_len]
          return unpadded_data
  
      def _get_header(self, data):
          """
          Return header from the provided data.
          """
          if len(data) < self.header_size:
              raise ValueError('Corrupted data - missing or invalid header')
  
          header = data[:self.header_size]
          return header
  
      def _remove_header(self, data):
          """
          Remove header from the provided data.
          """
          if len(data) < self.header_size:
              raise ValueError('Corrupted data - missing or invalid header')
  
          data = data[self.header_size:]
          return data
  
new_contents: # Licensed to Tomaz Muraus under one or more
  # contributor license agreements.  See the NOTICE file distributed with
  # this work for additional information regarding copyright ownership.
  # Tomaz muraus licenses this file to You under the Apache License, Version 2.0
  # (the "License"); you may not use this file except in compliance with
  # the License.  You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  class HybridCryptoMixin(object):
      block_size = 16
      header_size = 4  # Encrypted message header size (in bytes)
      # When message can't be encryted using only PKC and hybrid mode
      # is used
      long_message_threshold = (2048 / 8) - 41
      aes_key_size = 256 / 8  # Size of the generated AES key (in bytes)
      delimiter = ':'
  
      def _pad_data(self, data):
          """
          Pad provided data using PKCS#7.
          """
          # Data needs to be padded with at least 1 byte
          pad_len = self.block_size - (len(data) % self.block_size)
          pad_byte = chr(pad_len)
          pad_value = pad_len * pad_byte
  
          padded_data = data + pad_value
          return padded_data
  
      def _unpad_data(self, data):
          """
          Unpad provided data using PKCS#7.
          """
          pad_len = ord(data[-1])
  
          if pad_len > len(data):
              raise ValueError('Corrupted data')
  
          unpadded_data = data[:-pad_len]
          return unpadded_data
  
      def _get_header(self, data):
          """
          Return header from the provided data.
          """
          if len(data) < self.header_size:
              raise ValueError('Corrupted data - missing or invalid header')
  
          header = data[:self.header_size]
          return header
  
      def _remove_header(self, data):
          """
          Remove header from the provided data.
          """
          if len(data) < self.header_size:
              raise ValueError('Corrupted data - missing or invalid header')
  
          data = data[self.header_size:]
          return data
  
subject: Fix lint.