From 01ea3d4b9a3c6f3e0303c2d421a248715a96af99 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 24 May 2016 17:52:35 +0100 Subject: Fix handling of integer wraparound in megolm.c --- src/megolm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/megolm.c b/src/megolm.c index 6d8af08..a969b36 100644 --- a/src/megolm.c +++ b/src/megolm.c @@ -108,8 +108,12 @@ void megolm_advance_to(Megolm *megolm, uint32_t advance_to) { uint32_t mask = (~(uint32_t)0) << shift; int k; - /* how many times to we need to rehash this part? */ - int steps = (advance_to >> shift) - (megolm->counter >> shift); + /* how many times do we need to rehash this part? + * + * '& 0xff' ensures we handle integer wraparound correctly + */ + unsigned int steps = + ((advance_to >> shift) - (megolm->counter >> shift)) & 0xff; if (steps == 0) { continue; -- cgit v1.2.3