40 lines
1.5 KiB
Python
40 lines
1.5 KiB
Python
# MIT License
|
|
#
|
|
# Copyright (c) 2022 Mark Qvist / unsigned.io
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
# of this software and associated documentation files (the "Software"), to deal
|
|
# in the Software without restriction, including without limitation the rights
|
|
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
# copies of the Software, and to permit persons to whom the Software is
|
|
# furnished to do so, subject to the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be included in all
|
|
# copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
# SOFTWARE.
|
|
|
|
class PKCS7:
|
|
BLOCKSIZE = 16
|
|
|
|
@staticmethod
|
|
def pad(data, bs=BLOCKSIZE):
|
|
l = len(data)
|
|
n = bs-l%bs
|
|
v = bytes([n])
|
|
return data+v*n
|
|
|
|
@staticmethod
|
|
def unpad(data, bs=BLOCKSIZE):
|
|
l = len(data)
|
|
n = data[-1]
|
|
if n > bs:
|
|
raise ValueError("Cannot unpad, invalid padding length of "+str(n)+" bytes")
|
|
else:
|
|
return data[:l-n] |