git.zerfleddert.de Git - fhem-stuff/blob - HMLAN/HMLAN_CRYPT.pm

   1 package HMLAN_CRYPT;
   2
   3 use Crypt::Rijndael;
   4
   5 sub decrypt(@)
   6 {
   7         my ($self, $ciphertext) = @_;
   8         my $plaintext = '';
   9
  10         while($ciphertext) {
  11                 if($self->{'keystream'}) {
  12                         my $len;
  13
  14                         if (length($self->{'keystream'}) > length($ciphertext)) {
  15                                 $len = length($ciphertext);
  16                         } else {
  17                                 $len = length($self->{'keystream'});
  18                         }
  19
  20                         my $cpart = substr($ciphertext, 0, $len);
  21                         my $kpart = substr($self->{'keystream'}, 0, $len);
  22
  23                         $ciphertext = substr($ciphertext, $len);
  24                         $self->{'keystream'} = substr($self->{'keystream'}, $len);
  25
  26                         $self->{'ciphertext'} .= $cpart;
  27
  28                         $plaintext .= $cpart ^ $kpart;
  29                 } else {
  30                         $self->{'keystream'} = $self->{'cipher'}->encrypt($self->{'ciphertext'});
  31                         $self->{'ciphertext'}='';
  32                 }
  33         }
  34
  35         $plaintext;
  36 }
  37
  38 sub encrypt(@)
  39 {
  40         my ($self, $plaintext) = @_;
  41         my $ciphertext = '';
  42
  43         while($plaintext) {
  44                 if($self->{'keystream'}) {
  45                         my $len;
  46
  47                         if (length($self->{'keystream'}) > length($plaintext)) {
  48                                 $len = length($plaintext);
  49                         } else {
  50                                 $len = length($self->{'keystream'});
  51                         }
  52
  53                         my $ppart = substr($plaintext, 0, $len);
  54                         my $kpart = substr($self->{'keystream'}, 0, $len);
  55
  56                         $plaintext = substr($plaintext, $len);
  57                         $self->{'keystream'} = substr($self->{'keystream'}, $len);
  58
  59                         $self->{'ciphertext'} .= $ppart ^ $kpart;
  60
  61                         $ciphertext .= $ppart ^ $kpart;
  62                 } else {
  63                         $self->{'keystream'} = $self->{'cipher'}->encrypt($self->{'ciphertext'});
  64                         $self->{'ciphertext'}='';
  65                 }
  66         }
  67
  68         $ciphertext;
  69 }
  70
  71 sub new
  72 {
  73         my $class = shift;
  74         my $key = shift;
  75         my $iv = shift;
  76
  77         my $self = {
  78                 cipher          => Crypt::Rijndael->new($key, Crypt::Rijndael::MODE_ECB()),
  79                 keystream       => '',
  80                 ciphertext      => $iv,
  81         };
  82
  83         bless $self, $class;
  84 }
  85
  86 1;