mitmproxy/libmproxy/contrib/jsbeautifier/unpackers/javascriptobfuscator.py
Aldo Cortesi 2240d2a6a5 Pretty view now indents Javascript.
Thanks to the JSBeautifier project, which is now included in the contrib directory.
2012-03-25 10:56:45 +13:00

59 lines
1.7 KiB
Python

#
# simple unpacker/deobfuscator for scripts messed up with
# javascriptobfuscator.com
#
# written by Einar Lielmanis <einar@jsbeautifier.org>
# rewritten in Python by Stefano Sanfilippo <a.little.coder@gmail.com>
#
# Will always return valid javascript: if `detect()` is false, `code` is
# returned, unmodified.
#
# usage:
#
# if javascriptobfuscator.detect(some_string):
# some_string = javascriptobfuscator.unpack(some_string)
#
"""deobfuscator for scripts messed up with JavascriptObfuscator.com"""
import re
PRIORITY = 1
def smartsplit(code):
"""Split `code` at " symbol, only if it is not escaped."""
strings = []
pos = 0
while pos < len(code):
if code[pos] == '"':
word = '' # new word
pos += 1
while pos < len(code):
if code[pos] == '"':
break
if code[pos] == '\\':
word += '\\'
pos += 1
word += code[pos]
pos += 1
strings.append('"%s"' % word)
pos += 1
return strings
def detect(code):
"""Detects if `code` is JavascriptObfuscator.com packed."""
# prefer `is not` idiom, so that a true boolean is returned
return (re.search(r'^var _0x[a-f0-9]+ ?\= ?\[', code) is not None)
def unpack(code):
"""Unpacks JavascriptObfuscator.com packed code."""
if detect(code):
matches = re.search(r'var (_0x[a-f\d]+) ?\= ?\[(.*?)\];', code)
if matches:
variable = matches.group(1)
dictionary = smartsplit(matches.group(2))
code = code[len(matches.group(0)):]
for key, value in enumerate(dictionary):
code = code.replace(r'%s[%s]' % (variable, key), value)
return code