RE: [SLUG] Anyone used Perl's Filter package !!

[education]

Hi Angus:

My replies under [Louis].

 -Original Message-
 From: Angus Lees [mailto:[EMAIL PROTECTED]
 Sent: Tuesday, 28 October 2003 20:37
 To: [EMAIL PROTECTED]
 Cc: [EMAIL PROTECTED]
 Subject: Re: [SLUG] Anyone used Perl's Filter package !!


 At Mon, 27 Oct 2003 13:17:11 +1100 (EST), education  wrote:
  I download the package Filter-1.26 from CPAN. I'm having problems
  understanding how to use this package to get Perl code to
 go through
  the filter before compilation.

  Also does this method clearly prevents anyone from seeing
 the source
  code of a Perl script ?

 Unless it uses some form of encryption, then all you've done
 is obscured the code - anyone who can use the same filter can
 read the source code.

 See Embperl for an example of a module which *does* do
 encrypted source code - you compile a private key into the
 embperl module and then use it to encrypt source code files
 (see crypto/README in Embperl source).


[Louis] This is not installed on my server. I will get it installed to
play with. However I have just read about it from CPAN from the reference
you gave. I have some questions about this.
Here goes:

Q1. This may sound basic. I suppose if I encrypt the file, then if I run
it on another server, does it just needs EmbPerl (same version or any
version) installed ?

I read from the README that the epcrypto_config.h file needs to be
edited to enable encryption and choose the algorithm to use.

Q2. Does the setup for this part on the other server have to be the same ?
i.e for the other server to decrypt the binary and run the perl script the
header file has to be edited and recompiled to use the exact algorithm ?
Can't EmbPerl detect what algorithm to use when decrypting ?

Q3. When encrypting the file from the epcrypto program, can I name the
destination filename as a .pl script ?

Q4. As this is a Perl script I am trying to encrypt, does the path to perl
have to be in the source before encryption ? Will the script work if I add
the path to perl manually in the destination filename ?

Q5. Finally I suppose all I distribute is the destination encrypted files,
and DO NOT give out the source files from the crypto directory ?

Once I get it installed I will play with it a little bit. If I need more
help I'll post again.

Cheers.


-- 
SLUG - Sydney Linux User's Group - http://slug.org.au/
More Info: http://lists.slug.org.au/listinfo/slug

Re: [SLUG] Anyone used Perl's Filter package !!

[Angus Lees]

At Mon, 27 Oct 2003 13:17:11 +1100 (EST), education  wrote:
 I download the package Filter-1.26 from CPAN. I'm having problems
 understanding how to use this package to get Perl code to go through the
 filter before compilation.

 Also does this method clearly prevents anyone from seeing the source code
 of a Perl script ?

Unless it uses some form of encryption, then all you've done is
obscured the code - anyone who can use the same filter can read the
source code.

See Embperl for an example of a module which *does* do encrypted
source code - you compile a private key into the embperl module and
then use it to encrypt source code files (see crypto/README in Embperl
source).


Be aware that a determined person with access to the files and the
ability to run them can always find out what it does.  You'd have to
have some peculiar needs to make this approach worth the effort (as
opposed to simple restrictive file permissions, for example).

-- 
 - Gus

-- 
SLUG - Sydney Linux User's Group - http://slug.org.au/
More Info: http://lists.slug.org.au/listinfo/slug