commit 1ced222120c00854865c5b16e89838235ed549ee
parent 6ddd4bf6ac04ae0b8ba39fb4124e844afc49b5a9
Author: Sergey M․ <dstftw@gmail.com>
Date:   Wed, 27 Nov 2019 02:26:42 +0700

[utils] Add generic caesar cipher and rot47

Diffstat:
Mtest/test_utils.py | 16++++++++++++++++
Myoutube_dl/utils.py | 13+++++++++++++
2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/test/test_utils.py b/test/test_utils.py @@ -19,6 +19,7 @@ from youtube_dl.utils import ( age_restricted, args_to_str, encode_base_n, + caesar, clean_html, date_from_str, DateRange, @@ -69,6 +70,7 @@ from youtube_dl.utils import ( remove_start, remove_end, remove_quotes, + rot47, shell_quote, smuggle_url, str_to_int, @@ -1369,6 +1371,20 @@ Line 1 self.assertRaises(ValueError, encode_base_n, 0, 70) self.assertRaises(ValueError, encode_base_n, 0, 60, custom_table) + def test_caesar(self): + self.assertEqual(caesar('ace', 'abcdef', 2), 'cea') + self.assertEqual(caesar('cea', 'abcdef', -2), 'ace') + self.assertEqual(caesar('ace', 'abcdef', -2), 'eac') + self.assertEqual(caesar('eac', 'abcdef', 2), 'ace') + self.assertEqual(caesar('ace', 'abcdef', 0), 'ace') + self.assertEqual(caesar('xyz', 'abcdef', 2), 'xyz') + self.assertEqual(caesar('abc', 'acegik', 2), 'ebg') + self.assertEqual(caesar('ebg', 'acegik', -2), 'abc') + + def test_rot47(self): + self.assertEqual(rot47('youtube-dl'), r'J@FEF36\5=') + self.assertEqual(rot47('YOUTUBE-DL'), r'*~&%&qt\s{') + def test_urshift(self): self.assertEqual(urshift(3, 1), 1) self.assertEqual(urshift(-3, 1), 2147483646) diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py @@ -5383,6 +5383,19 @@ def decode_packed_codes(code): obfucasted_code) +def caesar(s, alphabet, shift): + if shift == 0: + return s + l = len(alphabet) + return ''.join( + alphabet[(alphabet.index(c) + shift) % l] if c in alphabet else c + for c in s) + + +def rot47(s): + return caesar(s, r'''!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~''', 47) + + def parse_m3u8_attributes(attrib): info = {} for (key, val) in re.findall(r'(?P<key>[A-Z0-9-]+)=(?P<val>"[^"]+"|[^",]+)(?:,|$)', attrib):