Beefy Boxes and Bandwidth Generously Provided by pair Networks
Come for the quick hacks, stay for the epiphanies.
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

At this node PerlApp decompile? a fellow monk chinman has asked for the help of the perl monks. He has compiled a script usiing PerlApp from Active State. His problem is that he has lost the source code. Decompiling the app is trivial and generates 4 source code files (amingst others) that chinman wishes to retrieve. Having established to my satisfaction that the afore mentioned monk did indeed generate this app (he correctly names all the component scripts, etc) the challenge is now to regenerate his original source. Now Active State has encoded the script data so that it is no longer simple ASCII so this is no gimmee.

But what is the encoding algorithm? To shed some light I asked him to encode this script:
#!"#$%&'()*+,-./0123456789:;<=>?@ #ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_` #abcdefghijklmnopqrstuvwxyz{|}~ #!"#$%&'()*+,-./0123456789:;<=>?@ #ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_` #abcdefghijklmnopqrstuvwxyz{|}~ #!"#$%&'()*+,-./0123456789:;<=>?@ #ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_` #abcdefghijklmnopqrstuvwxyz{|}~ print "Show me the encoding!\n";

The embedded encoded script is interesting. As it is binary encoded and unlikely to pass easily through PM i have used the following subto encode both the original and the embedded PerlApp script:

sub print_enc { my $file = shift; my $count = 0; open FILE, $file or die; binmode FILE; local $/; my $stuff = <FILE>; my @stuff = split //,$stuff; for (@stuff) { print ord($_),","; print "\n" unless ++$count %10; } print "\nCount $count\n"; }

Here is the unecoded and encoded data with a script to regenerate the original source data (note we are using WIN32 so we have CRLF -> chr 13 10. In the unencoded part you can easily see the ASCII series but in the embedded script it is gone. The ratio of 343:333 indicates that a simple 8:7 bitshift is not what has been done but what has? Nor does the pattern obviously repeat.

@unencoded = ( 35,33,34,35,36,37,38,39,40,41, 42,43,44,45,46,47,48,49,50,51, 52,53,54,55,56,57,58,59,60,61, 62,63,64,13,10,35,65,66,67,68, 69,70,71,72,73,74,75,76,77,78, 79,80,81,82,83,84,85,86,87,88, 89,90,91,92,93,94,95,96,13,10, 35,97,98,99,100,101,102,103,104,105, 106,107,108,109,110,111,112,113,114,115, 116,117,118,119,120,121,122,123,124,125, 126,13,10,35,33,34,35,36,37,38, 39,40,41,42,43,44,45,46,47,48, 49,50,51,52,53,54,55,56,57,58, 59,60,61,62,63,64,13,10,35,65, 66,67,68,69,70,71,72,73,74,75, 76,77,78,79,80,81,82,83,84,85, 86,87,88,89,90,91,92,93,94,95, 96,13,10,35,97,98,99,100,101,102, 103,104,105,106,107,108,109,110,111,112, 113,114,115,116,117,118,119,120,121,122, 123,124,125,126,13,10,35,33,34,35, 36,37,38,39,40,41,42,43,44,45, 46,47,48,49,50,51,52,53,54,55, 56,57,58,59,60,61,62,63,64,13, 10,35,65,66,67,68,69,70,71,72, 73,74,75,76,77,78,79,80,81,82, 83,84,85,86,87,88,89,90,91,92, 93,94,95,96,13,10,35,97,98,99, 100,101,102,103,104,105,106,107,108,109, 110,111,112,113,114,115,116,117,118,119, 120,121,122,123,124,125,126,13,10,112, 114,105,110,116,32,34,83,104,111,119, 32,109,101,32,116,104,101,32,101,110, 99,111,100,105,110,103,33,92,110,34, 59,13,10,); # Count 343 chars print chr($_) for @unencoded; print "\n###############\n"; @encoded = ( 96,78,82,90,86,76,65,79,92,9, 131,11,30,29,30,31,16,112,81,71, 93,67,83,100,76,88,78,94,28,105, 81,80,44,42,96,46,48,51,106,6, 41,55,49,59,35,44,36,57,110,230, 112,99,98,99,100,117,23,52,44,48, 44,62,15,41,63,43,5,42,119,14, 13,15,68,38,9,21,24,71,41,4, 28,20,28,6,23,25,6,83,221,85, 68,71,72,73,90,58,31,9,23,124, 70,114,86,66,80,64,6,115,71,70, 70,11,111,66,92,95,30,114,93,67, 77,71,95,80,80,77,26,146,28,15, 14,15,112,42,98,34,54,42,50,32, 21,51,41,61,47,107,24,34,33,35, 112,18,61,33,36,123,21,56,40,32, 40,50,59,53,42,127,201,42,17,81, 82,83,68,36,5,19,1,31,15,56, 24,12,26,10,80,37,29,28,24,85, 53,24,10,9,84,56,19,13,7,120, 74,70,74,87,4,140,6,21,24,25, 26,11,109,78,90,70,70,84,97,71, 85,65,83,23,108,86,85,87,28,126, 81,77,48,36,96,46,50,58,54,44, 33,47,60,105,227,107,126,125,126,127, 112,16,49,39,61,35,51,4,44,56, 46,62,124,9,49,48,12,42,96,14, 16,19,74,38,9,23,17,27,3,12, 4,25,78,198,80,67,66,67,68,85, 55,20,12,16,12,30,47,9,31,126, 21,82,61,1,27,76,2,16,7,29, 7,14,46,10,80,13,26,12,71,13, 26,67,198,68,91,94,87,17,124,47, 65,79,99,); # Count 333 chars print chr($_) for @encoded;

Can you crack the code and help chinman? Perhaps more data will be required. I have asked for a linear string to check for repeats but this is what we have to work with currently.

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Edit Masem 2001-07-16 - READMORE moved per request


In reply to A real challenge by tachyon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others musing on the Monastery: (3)
As of 2024-04-19 05:53 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found