1 files changed, 56 insertions, 0 deletions
diff --git a/perl/mul.pl b/perl/mul.pl
new file mode 100644
index 0000000000..611a760625
--- /dev/null
+++ b/perl/mul.pl
@@ -0,0 +1,56 @@
+#!/usr/bin/perl
+
+use ExtUtils::testlib;
+
+use SSLeay;
+
+
+sub mul
+	{
+	my($ab,$cd,$num)=@_;
+
+	if ($num <= 4096)
+		{
+		return($ab*$cd);
+		}
+	else
+		{
+		my($a,$b,$c,$d,$n,$ac,$bd,$m,$t1,$t2);
+
+		$n=$num/2;
+
+		$a=$ab->mask_bits($n);
+		$b=$ab->rshift($n);
+		$c=$cd->mask_bits($n);
+		$d=$cd->rshift($n);
+
+		$t1=($b-$a);
+		$t2=($c-$d);
+		$m= &mul($t1,$t2,$n);
+		$ac=&mul($a,$c,$n);
+		$bd=&mul($b,$d,$n);
+		$m=$m+$ac+$bd;
+		$m=$m->lshift($n);
+		$bd=$bd->lshift($num);
+
+		$r=$ac+$m+$bd;
+		return($r);
+		}
+	}
+
+$num=4096*32;
+$a=SSLeay::BN::rand($num);
+$b=SSLeay::BN::rand($num);
+
+#for (1 .. 10)
+	{
+	$r=&mul($a,$b,$num);
+	}
+
+#for (1 .. 10)
+	{
+	$rr=$a*$b;
+	}
+
+$res=$rr-$r;
+print $res->bn2hex()."\n";