Line Noise

[kilinrax]

#!/usr/bin/perl -w 
 
use strict; $\=$/;$_=q&&;s()/#?=>$":}\~>\\!;/;$/=~s~
~s{;};$")!{$"\\:<_!;~e;y{%*-.$'&(#-<}$@-~$s;{y(;-?)=
r-{)!=s;y$T-_$`-|$;y}{-~}l-\}};s{!}$Y<$g&&redo}print

Edit: chipmunk 2001-05-23

[ChemBoy]

This is really, really, cool. I'm going to desecrate it by deobfuscating it merely because it gave me a deeper appreciation of how cool it is (and because I feel somewhat clever for being able to).

First, let's make it a little more readable...

Read more... (8 kB)

[tachyon]

# line noise by kilinrax
#
# another read and run dissection by tachyon 
#
# I needed to rearrange the line breaks and add 
# a space between the = and r on at the begining 
# of the third line to make this run as shown below
 
use strict; $\=$/;$_=q&&;s()/#?=>$":}\~>\\!;/;$/=~
s~~s{;};$")!{$"\\:<_!;~e;y{%*-.$'&(#-<}$@-~$s;{y(;-?)
= r-{)!=s;y$T-_$`-|$;y}{-~}l-\}};s{!}$Y<$g&&redo}print;

# this is an awesome obfu, here is a quick dissect
# first the exact original code with some whitespace

use strict; 
$\=$/;
$_=q&&;
s()/#?=>$":}\~>\\!;/;
$/ =~ s~~s{;};$")!{$"\\:<_!;~e;
y{%*-.$'&(#-<}$@-~$s;
{
    y(;-?)= r-{)!=s;
    y$T-_$`-|$;
    y}{-~}l-\}};
    s{!}$Y<$g && redo
}
print;

# make it a bit more readable by using
# the usual / for our s and tr (y); also the
# bareblock rearranged, and now executes only once
# as s/!/Y</g is only true once and we can do it 
# before all the transliteration

use strict; 
$\="\n"; # set output rec sep to newline, neat trick!
$_='';
s//#?=>$":}\~>\\!;/;
$/ =~ s//s{;};$")!{$"\\:<_!;/e;
tr/%*-.$'&(#-</@-~/s;
while (s/!/Y</g){
    tr/;-?/ r-{)!/s;
    tr/T-_/`-|/;
    tr/{-~/l-\}/; 
}
print;

# here it is with the $/ =~ s///e simplified as we only
# want the effect of the code evaled in the second part 
# the unecessary while block has been removed
# the unecessary /s modifiers on the trs are gone
# as there are no duplicate chars to squash
# and some print statements show the secrets

use strict; 
$\="\n";
$_='';
s//#?=>$":}\~>\\!;/; print "1: $_";
s/;/$")!{$"\\:<_!/;  print "2: $_";
tr/%*-.$'&(#-</@-~/; print "3: $_";
s/!/Y</g;            print "4: $_";
tr/;-?/ r-{)!/;      print "5: $_";
tr/T-_/`-|/;         print "6: $_";
tr/{-~/l-\}/;        print "7: $_";
print;


# You can see what happens, the reason the changes 
# occur are that the - within the tr (y) has a special 
# meaning - it specifies a range of chars to 
# transliterate. Although A-Z is common *-. is OK
# too, and certainly less readable!
#
# This is an really unreadable obfu, even in this state
# Top effort!!!
#
# tachyon

[larryk]

I get the following as output

Jtrs anoshe
b

larryk

[chipmunk]

Try it now; there was an unwanted space character at the end of each line, which interfered with the operation of the code.

[larryk]

++ now