#!/usr/local/bin/perl
use warnings;
use strict;
use Crypt::CBC;
use Crypt::DES;			# give compile-time error if uninstalled
use Digest::MD5 qw/md5/;

die "$0: Gimme a password in environment variable PASSWD\n"
  unless exists $ENV{PASSWD};
my $cr = new Crypt::CBC ({ key => $ENV{PASSWD},
			   cipher => 'DES',
			 });
$cr->start('encrypting');

my $hdr =  <<'END_HEADER';
    #!/usr/local/bin/perl
    use warnings;
    use strict;
    use Crypt::CBC;
    use Crypt::DES;		# give compile-time error if uninstalled
    use Digest::MD5 qw/md5/;
    
    my $cr = new Crypt::CBC ({ key => $ENV{PASSWD},
                               cipher => 'DES',
                             });
    $cr->start('decrypting');
    eval join '', (map {$cr->crypt(unpack 'u',$_)} <DATA>), $cr->finish;
    __END__
END_HEADER

$hdr =~ s/^ {4}//mg;
print $hdr;

while (<>) {
  print pack 'u', $cr->crypt($_);
}
print pack 'u', $cr->finish;