Avoid undefined operation in rotation operations

1 files changed, 4 insertions, 0 deletions

diff --git a/src/utils/rotate.h b/src/utils/rotate.h
index 465746e0b..2593010b4 100644
--- a/src/utils/rotate.h
+++ b/src/utils/rotate.h
@@ -20,6 +20,8 @@ namespace Botan {
 */
 template<typename T> inline T rotate_left(T input, size_t rot)
    {
+   if(rot == 0)
+      return input;
    return static_cast<T>((input << rot) | (input >> (8*sizeof(T)-rot)));;
    }
 
@@ -31,6 +33,8 @@ template<typename T> inline T rotate_left(T input, size_t rot)
 */
 template<typename T> inline T rotate_right(T input, size_t rot)
    {
+   if(rot == 0)
+      return input;
    return static_cast<T>((input >> rot) | (input << (8*sizeof(T)-rot)));
    }