encodejs.py

#!/usr/bin/env python
# Usage: encodejs.py <fileToEncode>
#
# Encodes a js file using percent encoding.
# Resulting file calls unescape() and eval() to decode and execute the encoded string.
#
# Discovered while trying to get anonym.to's anonymize.js (http://js.anonym.to/anonym/anonymize.js)
#   to anonymize https links as well as http. Thought it was a goofy and unnecessary
#   obfuscation strategy. So I wrote up an encoder.
# Modified anonymize.js script at https://gist.github.com/phracker/b952b618e19a01a623de

import sys,os

es = "eval(unescape('"

def usage():
  print "Usage: encodejs.py <fileToEncode>"

args = sys.argv
del args[0]
if(len(args) != 1):
  usage()
  sys.exit()

fPath = os.path.expanduser(args[0])
fPathName, fPathExt = os.path.splitext(fPath)

if(fPathExt != ".js"):
  print "Not a .js file. Aborting."
  usage()
  sys.exit()

o = open(fPathName + ".enc" + fPathExt,"w")

with open(fPath) as f:
  while True:
    c = f.read(1)
    if not c:
      es = es + "'));"
      o.write(es)
      o.close()
      f.close()
      print "Success! File written to: " + fPathName + ".enc" + fPathExt
      break
    ec = "%" + hex(ord(c)).split('x')[1]
    es = es + ec