[ActiveLock-Development] First security hole spotted (and sealed - hopefully)

[Thanh H. T. <th...@sy...>]

Just to let everyone know, Dan Sanders (wizzardme2000) found the first =
gaping hole with my md5 checksum bit. Turns out someone can write a fake =
ALCrypto.dll with a dummy md5_hash function which can return the =
epxected checksum for ActiveLock2.dll, effectively fooling the app into =
thinking that ActiveLock2.dll is authentic when in fact it may  have =
been tampered. Looks like I'm going to have resort to the =
MapFileAndCheckSum() API call suggested on the forum by vbclassicforever =
a while back.
Round of applause for Dan. :-) Hack on, bro! Now it gets a little =
interesting.

Anyway, below are the excerpts from our conversation, if anyone's =
interested.
Cheers,
Thanh.
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02/08/2003  12:38:23 AM  Dan  Thanh  Are you working on the multiple =
lock-types thing, or am I still on that?=20
02/08/2003  12:38:42 AM  Thanh  Dan  i'll take it from here...thanks=20
02/08/2003  12:38:53 AM  Dan  Thanh  ok, cause I have free time now=20
02/08/2003  12:39:20 AM  Thanh  Dan  ok=20
02/08/2003  12:40:18 AM  Thanh  Dan  if you have time...may be you can =
play with softice/smartcheck some more to see if you can crack it....=20
02/08/2003  12:41:36 AM  Dan  Thanh  ok... and just to let you know, you =
dont have to "if (lockto and lockhd) =3D lockhd then"... you can use "if =
lockto and lock hd then". It has the same effect, but it seem a little =
more english=20
02/08/2003  12:42:10 AM  Thanh  Dan  yeah i figured as much....just that =
it's easier to read=20
02/08/2003  12:53:51 AM  Dan  Thanh  I think I found the kind of hole =
you were looking for...=20
02/08/2003  1:05:30 AM  Dan  Thanh  All you have to do to use a fake =
activelock2.dll is make a fake alcrypto.dll that works properly on md5 =
hashes, and checks if its testing a dll, then returns a fake hash so =
that the program wont know. I don't know what to do to fix it, but =
something along the lines of adding md5 dll hashing functions to the =
actual apps so that they can chack alcrypto and activelock2 themselves =
might be in order.=20