HMLAN AES-CFB implementation

[fhem-stuff] / HMLAN / HMLAN_CRYPT.pm

diff --git a/HMLAN/HMLAN_CRYPT.pm b/HMLAN/HMLAN_CRYPT.pm
new file mode 100644 (file)
index 0000000..12604b1
--- /dev/null
+++ b/HMLAN/HMLAN_CRYPT.pm
@@ -0,0 +1,86 @@
+package HMLAN_CRYPT;
+
+use Crypt::Rijndael;
+
+sub decrypt(@)
+{
+       my ($self, $ciphertext) = @_;
+       my $plaintext = '';
+
+       while($ciphertext) {
+               if($self->{'keystream'}) {
+                       my $len;
+
+                       if (length($self->{'keystream'}) > length($ciphertext)) {
+                               $len = length($ciphertext);
+                       } else {
+                               $len = length($self->{'keystream'});
+                       }
+
+                       my $cpart = substr($ciphertext, 0, $len);
+                       my $kpart = substr($self->{'keystream'}, 0, $len);
+
+                       $ciphertext = substr($ciphertext, $len);
+                       $self->{'keystream'} = substr($self->{'keystream'}, $len);
+
+                       $self->{'ciphertext'} .= $cpart;
+
+                       $plaintext .= $cpart ^ $kpart;
+               } else {
+                       $self->{'keystream'} = $self->{'cipher'}->encrypt($self->{'ciphertext'});
+                       $self->{'ciphertext'}='';
+               }
+       }
+
+       $plaintext;
+}
+
+sub encrypt(@)
+{
+       my ($self, $plaintext) = @_;
+       my $ciphertext = '';
+
+       while($plaintext) {
+               if($self->{'keystream'}) {
+                       my $len;
+
+                       if (length($self->{'keystream'}) > length($plaintext)) {
+                               $len = length($plaintext);
+                       } else {
+                               $len = length($self->{'keystream'});
+                       }
+
+                       my $ppart = substr($plaintext, 0, $len);
+                       my $kpart = substr($self->{'keystream'}, 0, $len);
+
+                       $plaintext = substr($plaintext, $len);
+                       $self->{'keystream'} = substr($self->{'keystream'}, $len);
+
+                       $self->{'ciphertext'} .= $ppart ^ $kpart;
+
+                       $ciphertext .= $ppart ^ $kpart;
+               } else {
+                       $self->{'keystream'} = $self->{'cipher'}->encrypt($self->{'ciphertext'});
+                       $self->{'ciphertext'}='';
+               }
+       }
+
+       $ciphertext;
+}
+
+sub new
+{
+       my $class = shift;
+       my $key = shift;
+       my $iv = shift;
+
+       my $self = {
+               cipher          => Crypt::Rijndael->new($key, Crypt::Rijndael::MODE_ECB()),
+               keystream       => '',
+               ciphertext      => $iv,
+       };
+
+       bless $self, $class;
+}
+
+1;