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@poizan42 poizan42/revenc.py
Last active Sep 4, 2019

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What would you like to do?
A tool for finding encodings that encodes a given string to a given binary value, or for finding possible combinations of encoding+decoding that would convert a string to a given mojibake
#/usr/bin/env python3
import re
import sys
import encodings
import pkgutil
all_encodings = set()
for _, modname, _ in pkgutil.iter_modules(
encodings.__path__, encodings.__name__ + '.',
):
try:
mod = __import__(modname, fromlist=[str('__trash')])
except (ImportError, LookupError):
# A few encodings are platform specific: mcbs, cp65001
# print('skip {}'.format(modname))
continue
try:
enc = mod.getregentry()
try:
if not enc._is_text_encoding:
continue
except AttributeError:
try:
''.encode(enc.name)
except LookupError:
continue
all_encodings.add(enc.name)
except AttributeError as e:
# the `aliases` module doensn't actually provide a codec
# print('skip {}'.format(modname))
if 'regentry' not in str(e):
raise
all_encodings -= set(['unicode-internal', 'undefined', 'mbcs', 'oem', 'raw-unicode-escape', 'unicode-escape', 'charmap'])
try:
import ebcdic
all_encodings |= set(ebcdic.codec_names)
except ModuleNotFoundError:
pass
try:
import cbmcodecs
all_encodings |= {'petscii-c64en-lc', 'petscii-c64en-uc', 'petscii-vic20en-lc', 'petscii-vic20en-uc', 'screencode-c64-lc', 'screencode-c64-uc'}
except ModuleNotFoundError:
pass
all_encodings = sorted(all_encodings)
found = False
if sys.argv[1] == '-f':
strseen = sys.argv[2]
strreal = sys.argv[3]
for enc_s in all_encodings:
try:
seen_enc = strseen.encode(enc_s)
except (LookupError, UnicodeError):
continue
for enc_r in all_encodings:
try:
real_enc = strreal.encode(enc_r)
except (LookupError, UnicodeError):
continue
if seen_enc == real_enc:
print('Found candidate: {}, {}'.format(enc_s, enc_r))
found = True
if not found:
print('No candidates found')
else:
strdata = sys.argv[1]
sval = sys.argv[2]
sval = re.sub(r'\s', '', sval)
if len(sval) % 2 == 1:
sval = u'0' + sval
val = bytes([int(sval[i:i+2], 16) for i in range(0, len(sval), 2)])
for enc in all_encodings:
try:
strenc = strdata.encode(enc)
except (LookupError, UnicodeError):
continue
if strenc == val:
print('Encoding match: ' + enc)
found = True
if not found:
print('No matching encoding found')
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