lib/crypto/bytes.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Mix of utilities and services related to bytes
  16 module bytes
  17
  18 redef class Bytes
  19         # PKCS#7 padding.
  20         #
  21         # Extends `self` by appending the number of bytes of padding to the end of the block.
  22         #
  23         #     assert "YELLOW SUBMARINE".to_bytes.pkcs7(20) == "YELLOW SUBMARINE\x04\x04\x04\x04".to_bytes
  24         fun pkcs7(blocksize: Int): Bytes
  25         do
  26                 var mod = length % blocksize
  27                 if mod == 0 then return self
  28                 var pad = blocksize - mod
  29                 var byte = pad
  30                 for i in [0..pad[ do add byte
  31                 return self
  32         end
  33 end