From 7836eda2dea521f15eb59b08e940719790c74349 Mon Sep 17 00:00:00 2001
From: Michael Gernoth <michael@gernoth.net>
Date: Sun, 2 Jun 2013 11:46:13 +0200
Subject: [PATCH] HMLAN AES-CFB implementation

---
 HMLAN/HMLAN_CRYPT.pm      | 86 +++++++++++++++++++++++++++++++++++++++
 HMLAN/hmlan-crypt-test.pl | 59 +++++++++++++++++++++++++++
 2 files changed, 145 insertions(+)
 create mode 100644 HMLAN/HMLAN_CRYPT.pm
 create mode 100755 HMLAN/hmlan-crypt-test.pl

diff --git a/HMLAN/HMLAN_CRYPT.pm b/HMLAN/HMLAN_CRYPT.pm
new file mode 100644
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;
diff --git a/HMLAN/hmlan-crypt-test.pl b/HMLAN/hmlan-crypt-test.pl
new file mode 100755
index 0000000..e80bf6f
--- /dev/null
+++ b/HMLAN/hmlan-crypt-test.pl
@@ -0,0 +1,59 @@
+#!/usr/bin/perl -w
+
+my $key="RUTYOURSECRETHMLANSTICKERKEYHERE";
+my $hmlan="192.168.1.2";
+
+BEGIN {
+	use File::Basename;
+	push @INC, dirname($0);
+}
+
+use HMLAN_CRYPT;
+use IO::Socket::INET;
+use IO::Select;
+
+#This should be random...
+my $my_iv = '00112233445566778899AABBCCDDEEFF';
+my $hmlan_iv = '';
+
+my $sock = IO::Socket::INET->new(
+	PeerAddr => $hmlan,
+	PeerPort => 1000,
+	Proto => 'tcp',
+	Blocking => 0);
+
+my $read_set = new IO::Select();
+$read_set->add($sock);
+
+$read_set->can_read();
+
+chomp(my $iv = <$sock>);
+if ($iv =~ /^V(................................)\r$/) {
+	$hmlan_iv = $1;
+} else {
+	print STDERR "Unknown IV received: ${iv}\n";
+	exit(1);
+}
+
+print $sock "V${my_iv}\r\n";
+
+my $cipher_hmlan=HMLAN_CRYPT->new(pack("H*", $key), pack("H*", $my_iv));
+my $cipher_pc=HMLAN_CRYPT->new(pack("H*", $key), pack("H*", $hmlan_iv));
+
+$read_set->add(\*STDIN);
+
+while(1) {
+	my @ready = $read_set->can_read();
+	foreach my $r (@ready) {
+		if ($r == $sock) {
+			while(my $buf=<$r>) {
+				print $cipher_hmlan->decrypt($buf);
+			}
+		} else {
+			my $buf = <$r>;
+			exit(1) if (!$buf);
+
+			print $sock $cipher_pc->encrypt($buf);
+		}
+	}
+}
-- 
2.39.2