index/index.py

   1 #!/usr/bin/env python
   2 import sys, md5, os, mmap
   3 from struct import unpack
   4
   5 #
   6 # We can brute force everything
   7 #
   8
   9 def xfferr (msg):
  10     sys.stderr.write (msg)
  11     sys.exit (1)
  12
  13 digs = {}
  14 def ent (map, pos):
  15     buf = map[pos:pos+20*4]
  16     D = unpack ("<20I", buf)
  17
  18     def r4 (off):
  19         return map[pos+off:pos+off+4]
  20
  21     if not buf[0:4] in ["xff\x00", "xff2"]:
  22         return None
  23
  24     if D[1] <> 0:
  25         return None
  26
  27     if D[2] <> 0:
  28         return None
  29
  30     size = D[5]
  31     entr = D[19]
  32
  33     buf = r4 (0x50 + 3*4)
  34     sechdroff = unpack ("<I", buf)[0] + 8 * 4
  35     secoff = unpack ("<I", r4 (sechdroff + 7*4))[0]
  36     buf = r4 (secoff + entr)
  37     if buf ==  "\x01\x00\x00\x00":
  38         return (size, "skb")
  39     elif buf == "\x0c\x00\x00\x00":
  40         return (size, "anb")
  41     elif buf == "NMO\x00":
  42         return (size, "nmo")
  43     elif buf == "NTO2":
  44         return (size, "nto")
  45     else:
  46         return None
  47
  48 def findname (map, pos, ext):
  49     startpos = pos - 16384
  50     if startpos < 0:
  51         startpos = 0
  52     buf = map[startpos:pos]
  53     pos = buf.rfind ("." + ext)
  54     if pos == -1:
  55         return None
  56     else:
  57         pos1 = buf[:pos].rfind ("\x00")
  58         if pos1 == -1:
  59             pos1 = 0
  60         return buf[pos1+1:pos+4]
  61
  62 def main (path):
  63     x = open (path, "rb")
  64     x.seek (0, 2)
  65     s = x.tell ()
  66     m = mmap.mmap (x.fileno (), s, mmap.MAP_PRIVATE, mmap.PROT_READ)
  67     h = {}
  68
  69     pos = 0
  70     chunk = 40000
  71     while pos < s:
  72         buf = m[pos:pos+chunk]
  73         off = buf.find ("xff\x00")
  74
  75         if off == -1:
  76             pos += chunk
  77             continue
  78
  79         pos += off
  80         tup = ent (m, pos)
  81         if tup == None:
  82             pos += 1
  83             continue
  84
  85         size, ext = tup
  86         name = findname (m, pos, ext)
  87         if not name in h:
  88             if name != None and name[0] <> 0x80:             # oh well
  89                 print "%x %10d %s" % (pos, size, name)
  90             h[name] = True
  91         pos += size
  92
  93 main (sys.argv[1])