Re: Writing highly obfuscated code in Perl

[cLive ;-)]

This is the shell of what I use. I actually build %replace_key manually. This version only works if you ensure that all subs and vars are unlikely to appear as words (or part of word) you print. Eg, don't use a var called $time if your script outputs something like:

print "The time is $time\n";

OK, here's the meat (unobfuscated, and well commented :)...

#!/usr/bin/perl
use strict;

print "Enter path to script: ";

my $script_path = (<STDIN>);

# read in script
open (SCRIPT, $script_path) || die("Can't find script $script_path - $
+!");
my $script_text = join '', (&lt;SCRIPT&gt;);
close(SCRIPT);

my %replace_key;

# read in vars of at least 2 chars - well, I always use $i anyway :)
while ($script_text =~ /\$(\w\w+)/gs) {
    $replace_key{$1} = 1;
}

# read in subs
while ($script_text =~ /sub (\w+)/gs) {
    $replace_key{$1} = 1;
}

my $i=1;
for (keys %replace_key) {
    my $replace    = unpack ("B32", pack("N", $i)); # get binary of $i
    $replace     =~ s/^0+(?=\d)//;               # remove trailing zer
+oes
    $replace     =~ s/0/I/g;                     # change 0 -> I
    $replace     =~ s/1/l/g;                     # change 1 -> l (lowe
+rcase L)
    $i++;
    $script_text =~ s/$_/$replace/gs;            # obfuscate

}

# remove extraneous CRs
$script_text =~ s/;\s*\n\s*/;\n/gis;

# now screw up tab spacing
$script_text =~ s/\t+/"\t" x (int(rand 6))/ges;

# take a look at your handywork
print $script_text;
exit(0);

Depending on the consistancy of your coding style, you can add other obfuscations. EG, I always mark comments as:

# ## comment

so I can rip them all out with

s/# ##[^\n]+\n\s*/\n/g;

I also use the following:

s/\{/n/ /g;
s/\}\s+elsif/} elsif/g;
s/;\s+my/; my/g;

That leaves your code totally readable, but when you run it through the obfuscater and let it loose... ;-)

Any othet s/obfuscation/pattern/ suggestions welcomed :)

later

cLive ;-)