Re: Controlling licensed software?

[prev] [thread] [next] [Date index for 2005/02/24]

> On Sun, 20 Feb 2005 20:26:07 -0500
> Stas Bekman <stas@xxxxxx.xxx> wrote:
> 
> > Adi Fairbank wrote:
> > > Take a look at Crypt::License on CPAN.  I used it a couple years
> > > back to do exactly what you are trying to do.  It encrypts your 
Perl
> > > source code and then decrypts it on the fly.  There is a slight
> > > overhead for the decryption, but if running under mod_perl, that
> > > should be negligible since it would only need to decrypt on 
apache
> > > startup.
> > 
> > Just be aware that if perl sees the decrypted code, the user can 
see
> > it too. It's not trivial but certainly doable, for example while
> > running under perl debugger. I wonder why Crypt::License docs don't
> > include any warning. Or do I miss something? I haven't tried this
> > particular module, but all the previous discussions about similar
> > modules had the conclusion that you can really hide the code, other
> > than making it harder to get to it.
> > 
> 
> Yes, it's fairly easy (for any programmer) to intercept the perl code
> after it is decrypted and before it's sent to the perl interpreter. 
> It
> would not be easy for the average user though (depending on who your
> users are).
> 
> But with Crypt::License, you will only be able to decrypt *if* you 
> have
> a valid license key.  That may not make a difference, if you are
> offering free trial versions, for example.
> 
> Stas, I'm sure you didn't miss anything in the Crypt::License docs..
> As
> I remember, the docs were very minimal and it took me a while just to
> figure out how to get it to work- and I had to look through the
> source
> quite a bit.
> 

I'm more than happy to accept donated documentation to add to the 
module :-)  I'm not a great writer (or tech writer) so any contribution
of "actual documentation" would be appreciated and accepted.

Michael