# -*- coding: UTF-8 -*-

"""XOR Codec - XOR-with-1-byte content encoding.

This codec:

- en/decodes strings from str to str

- en/decodes strings from bytes to bytes

- decodes file content to str (read)

- encodes file content from str to bytes (write)

"""

from ..__common__ import *

__examples__ = {

'enc(xor0|xor--10|xor256|xor300)': None,

'enc(xor3|xor-3|xor_3)': {'this is a test': "wkjp#jp#b#wfpw"},

'enc(xor3|xor-3|xor_3)': {'wkjp#jp#b#wfpw': "this is a test"},

'enc(xor6|xor-6|xor_6)': {'this is a test': "rnou&ou&g&rcur"},

}

__guess__ = ["xor-%d" % i for i in range(1, 256)]

def _xorn(text, n=1):

return "".join(chr(ord(c) ^ (n % 256)) for c in text)

def xor_byte_encode(i):

def encode(text, errors="strict"):

r = _xorn(ensure_str(text), i)

return r, len(r)

return encode

add("xor", xor_byte_encode, xor_byte_encode, r"^xor[-_]?([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$",

transitive=True)