From 9be6f384bae8ebeabc129ede9f8a597de12835d3 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Thu, 25 Jul 2019 10:58:40 +0300
Subject: [PATCH] Simplify mgm/incr

---
 src/cypherpunks.ru/gogost/mgm/mode.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/cypherpunks.ru/gogost/mgm/mode.go b/src/cypherpunks.ru/gogost/mgm/mode.go
index 2781cbb..20f77c7 100644
--- a/src/cypherpunks.ru/gogost/mgm/mode.go
+++ b/src/cypherpunks.ru/gogost/mgm/mode.go
@@ -101,10 +101,11 @@ func (mgm *MGM) Overhead() int {
 }
 
 func incr(data []byte) {
-	if len(data) == 4 {
-		binary.BigEndian.PutUint32(data, binary.BigEndian.Uint32(data)+1)
-	} else {
-		binary.BigEndian.PutUint64(data, binary.BigEndian.Uint64(data)+1)
+	for i := len(data) - 1; i >= 0; i-- {
+		data[i]++
+		if data[i] != 0 {
+			return
+		}
 	}
 }
 
-- 
2.44.0