Initial Commit

database/perl/vendor/lib/Digest/OMAC2.pm

@@ -0,0 +1,64 @@
+package Digest::OMAC2;
+
+use base qw(Digest::OMAC::Base);
+
+use strict;
+#use warnings;
+use Carp;
+use MIME::Base64;
+
+# we still call it Lu2 even though it's actually no longer squared ;-)
+
+sub _lu2 {
+	my ( $self, $blocksize,  $L ) = @_;
+	$self->_shift_lu2( $L, $self->_lu2_constant($blocksize) );
+}
+
+sub _shift_lu2 {
+	my ( $self, $L, $constant ) = @_;
+
+	# used to do Bit::Vector's shift_left but that's broken
+	my $unpacked = unpack("B*",$L);
+	my $lsb = chop $unpacked;
+	my $Lt = pack("B*", "0" . $unpacked);
+
+	if ( $lsb ) {
+		return $Lt ^ $constant;
+	} else {
+		return $Lt;
+	}
+}
+
+sub _lu2_constant {
+	my ( $self, $blocksize ) = @_;
+
+	if ( $blocksize == 16 ) { # 128
+		return ("\x80" . ("\x00" x 14) . "\x43");
+	} elsif ( $blocksize == 8 ) { # 64
+		return ("\x80" . ("\x00" x 6) . "\x0d");
+	} else {
+		die "Blocksize $blocksize is not supported by OMAC";
+	}
+}
+
+1;
+__END__
+
+=pod
+
+=head1 NAME
+
+Digest::OMAC2 - OMAC 2 implementation
+
+=head1 SYNOPSIS
+
+	use Digest::OMAC2;
+
+	my $d = Digest::OMAC2->new( $key, $cipher );
+
+=head1 DESCRIPTION
+
+OMAC 2 is a variant of the CMAC/OMAC 1 algorithm. The initialization routines
+are slightly different. OMAC2 actually precedes OMAC1, so
+L<Digest::CMAC>/L<Digest::OMAC1> is the reccomended version. Supposedly OMAC1
+was more rigorously analyzed.