From 1d3c778147884cc5760e8339a4615713401cf2fb Mon Sep 17 00:00:00 2001
From: John-Mark Gurney <jmg@funkthat.com>
Date: Wed, 31 May 2023 23:40:44 -0700
Subject: [PATCH] implement / (division), use self.__class__ more..

---
 shamirss.py | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/shamirss.py b/shamirss.py
index 72ed64e..7d9f43f 100644
--- a/shamirss.py
+++ b/shamirss.py
@@ -164,8 +164,8 @@ class GF2p8:
 
 	# basic operations
 	def __add__(self, o):
-		if isinstance(o, int):
-			return self + self.__class__(o)
+		if not isinstance(o, self.__class__):
+			o = self.__class__(o)
 
 		return self.__class__(self._v ^ o._v)
 
@@ -180,7 +180,7 @@ class GF2p8:
 
 	def __mul__(self, o):
 
-		if isinstance(o, int):
+		if not isinstance(o, self.__class__):
 			o = self.__class__(o)
 
 		m = o._v
@@ -199,9 +199,21 @@ class GF2p8:
 	def __rmul__(self, o):
 		return self.__mul__(o)
 
+	def __truediv__(self, o):
+		if not isinstance(o, self.__class__):
+			o = self.__class__(o)
+
+		return self * (o ** -1)
+
+	def __rtruediv__(self, o):
+		if not isinstance(o, self.__class__):
+			o = self.__class__(o)
+
+		return o * (self ** -1)
+
 	def __pow__(self, x):
 		if x == -1 and self._invcache:
-			return GF2p8(self._invcache[self._v])
+			return self.__class__(self._invcache[self._v])
 
 		if x < 0:
 			x += 255
@@ -225,8 +237,8 @@ class GF2p8:
 		return r
 
 	def __eq__(self, o):
-		if isinstance(o, int):
-			return self._v == o
+		if not isinstance(o, self.__class__):
+			o = self.__class__(o)
 
 		return self._v == o._v
 
@@ -330,6 +342,10 @@ class TestShamirSS(unittest.TestCase):
 		self.assertRaises(ValueError, GF2p8, 40.5)
 		self.assertRaises(ValueError, GF2p8, -1)
 
+	def test_gf2p8_div(self):
+		self.assertEqual(GF2p8(10) / 11, GF2p8(11) ** -1 * GF2p8(10))
+		self.assertEqual(10 / GF2p8(11), GF2p8(11) ** -1 * GF2p8(10))
+
 	def test_gf2p8(self):
 		self.assertEqual(int(GF2p8(5)), 5)
 		self.assertEqual(repr(GF2p8(5)), 'GF2p8(5)')