Fortify

Robert S. Thau (rst@ai.mit.edu)
Mon, 2 Mar 1998 18:59:28 -0500 (EST)


Robert Harley writes:
> Hey dewdz!!1!
>
> I D/Led dem Fortify warez and munged Netscape for Intel Linux.
>
> Fortify appears to do what it claims. No probs. 128-bit RC4 seems to
> be working fine (running Netscape in the x86 emulator for Alpha Linux).
>
> Dis rewls!

If you don't trust Fortify, the complete theory of its operation is
explained in a recent NetlyNews column (www.netlynews.com). It turns
out that all shipped Netscape binaries have code to implement all the
encryption modes that Netscape has available; there's also a
compiled-in table which controls which of the modes a *particular*
binary will be willing to use.

This table is also, of course, stored in the binary. As ASCII
strings. Without checksums, signatures, or anything else. With the
names of the encryption modes and the words 'false' and 'true'
spelled out in plain English, for those otherwise too dense to take
the hint.

(Of course, scrambling and binarizing the table would have only gotten
them security through obscurity, and not much of that; you can always
trace the binary to figure out where the table is, and patch it to
disable whatever integrity checks they have installed. Remember, very
elaborate multilevel integrity-check schemes proved insufficient to
copy-protect then-valuable Apple II games from moderately adept
teenagers. So it's not clear that Netscape has anything to be
embarassed by here...).

rst