From 7f8c2476ae775cfe27be5a216cebb6ad35432185 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 18 Oct 2019 22:15:46 +0100
Subject: [PATCH] ec.c (eccurve_pyrichcompare): Check that second operand has
 correct type.

A segfault waiting to happen, which has been lurking since the
beginning.
---
 ec.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/ec.c b/ec.c
index c8cdebe..0df218b 100644
--- a/ec.c
+++ b/ec.c
@@ -788,7 +788,11 @@ static PyTypeObject ecptcurve_pytype_skel = {
 
 static PyObject *eccurve_pyrichcompare(PyObject *x, PyObject *y, int op)
 {
-  int b = ec_samep(ECCURVE_C(x), ECCURVE_C(y));
+  int b;
+
+  assert(ECCURVE_PYCHECK(x));
+  if (!ECCURVE_PYCHECK(y)) RETURN_NOTIMPL;
+  b = ec_samep(ECCURVE_C(x), ECCURVE_C(y));
   switch (op) {
     case Py_EQ: break;
     case Py_NE: b = !b; break;
-- 
2.11.0