How to use LWP::Simpe inside a safe compartment?

[Anonymous Monk]

Hi,

I want to use LWP::Simple inside a safe compartment created with the Safe Module. But it ends up with errors like "Can't locate object method "new" via package "LWP::UserAgent" at line... or "Require trapped by operation mask..."

Here is how the code looks like (shortened ;-) ):

$codefromoutside='print wget "http://google.com";';

use LWP::Simple ();
sub wget { LWP::Simple::get $_[0] }

use Safe;
$safe=new Safe; $safe->share(qw(wget));

$safe->reval($codefromoutside);
print $@ if $@;

(There is a reason why I use "wget" instead of "get" directly because I have already a subroutine with the name "get" elsewhere)

I tried some other things but they all didn't work. Does anybody know how to use LWP::Simple::get inside a save compartment?

Thanks in advance,

best regards,

Christoph Bergmann

[jlongino]

First of all let me say that I know nothing about how Safe.pm works. However, I was able to run your program without errors with the following change:

  $codefromoutside='print wget "http://google.com";';

  use LWP::Simple ();
  sub wget { LWP::Simple::get $_[0] }

  use Safe;
  $safe=new Safe; 
  $safe->share(qw(LWP::Simple::get)); ## <- note change here

  $safe->reval($codefromoutside);
  print $@ if $@;

This may be inappropriate or not, I don't know, but maybe it helps.

--Jim

[Anonymous Monk]

Hi Jim...

Thanks for your try, but I didn't get any result with this code either. What should happen is that "googe.com" should be downloaded and printed out...

I tried:

$safe->share(qw(LWP::Simple::get wget));

but it gives

require trapped by operation mask at C:/Perl/5.00503/lib/IO/Socket.pm 
+line 9.

which means that LWP::Simple::get tries to load some stuff which is forbidden within the safe compartment.

Nobody any further ideas!?

Best regards,

Christoph Bergmann

[Anonymous Monk]

Take a look at http://perldoc.perl.org/Safe.html. You probably want to do a safe->permit('require').

I can't say that it will make your program work, but it will get you past that particular error.