Acme-Steganography-Image-Png

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Png.pm  view on Meta::CPAN

use vars qw($VERSION @ISA);

use Imager;
require Class::Accessor;
use Carp;

@ISA = qw(Class::Accessor);

$VERSION = '0.06';

my @keys = qw(offset data section x y datum_length done filename_generator
	      suffix);

# What arguments can we accept to the constructor.
# Am I reinventing the wheel here?
my %keys;
@keys{@keys} = ();

sub _keys {
  return \%keys;
}

Acme::Steganography::Image::Png->mk_accessors(@keys);

# This will get refactored out at some point to support other formats.
sub generate_header {
    my ($self) = shift;
    my $section = $self->section;

    my $header = pack 'w', $section;
    if (!$section) {
	$header .= pack 'w', length ${$self->data};
    }
    $header;
}

sub default_filename_generator {
  my $state = shift;
  $state ||= 0;
  my $new_state = $state+1;
  # really unimaginative filenames by default

Png.pm  view on Meta::CPAN

    $datum .= substr ${$self->data()}, $offset, $grab;
    $self->offset($offset + $grab);

    if (length $datum < $datum_length) {
      # Need to pad it. NUL is so uninspiring.
      $datum .= "N" x ($datum_length - length $datum);
      $self->done(1);
    } elsif (length ${$self->data()} == $self->offset) {
      warn length $datum;
    }
    $self->section($self->section + 1);

    $self->make_image($datum);
}

sub new {
  my $class = shift;
  croak "Use a classname, not a reference for " . __PACKAGE__ . "::new"
    if ref $class;
  my $self = bless {}, $class;
  my %args = @_;

Png.pm  view on Meta::CPAN

  $self;
}

sub type {
  'png';
}

sub write_images {
  my $self = shift;
  $self->section(0);
  $self->offset(0);
  $self->datum_length($self->calculate_datum_length());
  my $type = $self->type;
  my $filename_generator
    = $self->filename_generator || \&default_filename_generator;

  my @filenames;

  my ($filename, $state);
  while (!$self->done()) {

Png.pm  view on Meta::CPAN

  my $class = shift;
  # This is intentionally a "sparse" array to avoid some "interesting" DOS
  # possibilities.
  my $length;
  my %got;
  foreach my $file (@_) {
    my $img = new Imager;
    $img->open(file => $file) or carp "Can't read '$file': " . $img->errstr;
    my $payload = $class->extract_payload($img);
    my $datum;
    my $section;
    ($section, $datum) = unpack "wa*", $payload;
    if ($section == 0) {
      # Oops. Strip off the length.
      ($length, $datum) = unpack "wa*", $datum;
    }
    $got{$section} = $datum;
  }
  carp "Did not find first section in files @_" unless defined $length;

  my $data = join '', map {$got{$_}} sort {$a <=> $b} keys %got;
  substr ($data, $length) = '';

  $data;
}

1;
__END__

Png.pm  view on Meta::CPAN

  my @filenames = $writer->write_images("Camouflage.jpg");
  # Returns a list of the filenames it wrote to

  # Then read them back.
  my $reread =
     Acme::Steganography::Image::Png::RGB::556->read_files(@files);

=head1 DESCRIPTION

Acme::Steganography::Image::Png is extremely ineffective at hiding your
secrets inside Png images.

There are 4 implementations

=over 4

=item Acme::Steganography::Image::Png::FlashingNeonSignGrey

Blatantly stuffs your data into greyscale PNG files with absolutely no attempt
to hide it.

README  view on Meta::CPAN

Acme::Steganography::Image::Png version 0.06
============================================


Acme::Steganography::Image::Png is extremely ineffective at hiding your
secrets inside Png images.

If you want real steganography, you're in the wrong place.

INSTALLATION

To install this module type the following:

   perl Makefile.PL
   make
   make test