commit 8f81d8a3053ad0ef874cc015df13fca6ae1e583e
author David Horstmann <david.horstmann@arm.com> Wed Feb 15 13:46:53 2023 +0000
committer David Horstmann <david.horstmann@arm.com> Mon Feb 20 14:44:18 2023 +0000
tree 61ba7eeb4d0dbaef78d3adc3b12a770a27e2ddb2
parent b91ba4b7bf8d8ebeeae9fbebf159b6e1e5c19a09

Make overflow checks more readable

Signed-off-by: David Horstmann <david.horstmann@arm.com>

library/oid.c

diff --git a/library/oid.c b/library/oid.c
index fb4caad..e36caf2 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -806,7 +806,7 @@
 
     while (i < oid->len && ((oid->p[i] & 0x80) != 0)) {
         /* Prevent overflow in value. */
-        if (((value << 7) >> 7) != value) {
+        if (value > (UINT_MAX >> 7)) {
             return MBEDTLS_ERR_OID_BUF_TOO_SMALL;
         }
 
@@ -835,7 +835,7 @@
     value = 0;
     for (; i < oid->len; i++) {
         /* Prevent overflow in value. */
-        if (((value << 7) >> 7) != value) {
+        if (value > (UINT_MAX >> 7)) {
             return MBEDTLS_ERR_OID_BUF_TOO_SMALL;
         }
         if ((value == 0) && ((oid->p[i]) == 0x80)) {