fixed a singular-point detection failure in replay check. (Bug-ID 1714644)

1 files changed, 5 insertions, 2 deletions

diff --git a/common.c b/common.c
index 0a41dad..dd1a098 100644
--- a/common.c
+++ b/common.c
@@ -663,8 +663,11 @@ dhcp6_auth_replaycheck(method, prev, current)
 	prev = ntohq(prev);
 	current = ntohq(current);
 
-	/* we call the singular point guilty */
-        if (prev == (current ^ 8000000000000000ULL)) {
+	/*
+	 * we call the singular point guilty, since we cannot guess
+	 * whether the serial number is increasing or not.
+	 */
+        if (prev == (current ^ 0x8000000000000000ULL)) {
 		dprintf(LOG_INFO, FNAME, "detected a singular point");
 		return (1);
 	}