From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 5 Nov 2018 18:37:36 +0000 (+0300)
Subject: Fix 34.10 degree sanitizing
X-Git-Tag: 3.15~17
X-Git-Url: http://www.git.cypherpunks.ru/?p=pygost.git;a=commitdiff_plain;h=8e4df72ed17eebfcf9ba782bf8b8bf4def619608;ds=sidebyside

Fix 34.10 degree sanitizing
---

diff --git a/news.texi b/news.texi
index 68e672d..a0ca9d1 100644
--- a/news.texi
+++ b/news.texi
@@ -8,6 +8,9 @@
     @itemize
     @item Added mode argument to @code{pygost.gost3410_vko.kek_34102012256},
         because 256-bit private keys can be used with that algorithm too.
+    @item Fix incorrect degree sanitizing in
+        @code{pygost.gost3410.GOST3410Curve.exp} preventing using of
+        @code{UKM=1} in @code{pygost.gost3410_vko.kek_*} functions.
     @end itemize
 
 @anchor{Release 3.11}
diff --git a/pygost/gost3410.py b/pygost/gost3410.py
index 50de479..f608912 100644
--- a/pygost/gost3410.py
+++ b/pygost/gost3410.py
@@ -164,9 +164,9 @@ class GOST3410Curve(object):
         y = y or self.y
         tx = x
         ty = y
-        degree -= 1
         if degree == 0:
             raise ValueError("Bad degree value")
+        degree -= 1
         while degree != 0:
             if degree & 1 == 1:
                 tx, ty = self._add(tx, ty, x, y)