From b466bde5d0fd8daf989c3809f3def93369139d1a Mon Sep 17 00:00:00 2001
From: Daniel Pouzzner <douzzer@wolfssl.com>
Date: Tue, 4 Feb 2025 12:07:29 -0600
Subject: [PATCH] src/internal.c and src/ssl.c: in CheckcipherList() and
 ParseCipherList(), refactor "while (next++)" to "while (next)" to avoid
 clang21 UndefinedBehaviorSanitizer "applying non-zero offset 1 to null
 pointer".

---
 src/internal.c |  4 ++--
 src/ssl.c      | 13 +++++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/internal.c b/src/internal.c
index 3a375ccc4..0c8f34743 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -27822,6 +27822,7 @@ static int ParseCipherList(Suites* suites,
             }
             if (currLen == 0)
                 break;
+            ++next; /* increment to skip ':' */
         }
 
     #if defined(OPENSSL_EXTRA) || defined(OPENSSL_ALL)
@@ -28173,8 +28174,7 @@ static int ParseCipherList(Suites* suites,
                 break;
             }
         }
-    }
-    while (next++); /* increment to skip ':' */
+    } while (next);
 
     if (ret) {
         int keySz = 0;
diff --git a/src/ssl.c b/src/ssl.c
index babe37fe8..d684f19a9 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -9221,8 +9221,14 @@ static int CheckcipherList(const char* list)
 
         next   = XSTRSTR(next, ":");
 
-        current_length = (!next) ? (word32)XSTRLEN(current)
-                                 : (word32)(next - current);
+        if (next) {
+            current_length = (word32)(next - current);
+            ++next; /* increment to skip ':' */
+        }
+        else {
+            current_length = (word32)XSTRLEN(current);
+        }
+
         if (current_length == 0) {
             break;
         }
@@ -9279,8 +9285,7 @@ static int CheckcipherList(const char* list)
             /* list has mixed suites */
             return 0;
         }
-    }
-    while (next++); /* increment to skip ':' */
+    } while (next);
 
     if (findTLSv13Suites == 0 && findbeforeSuites == 1) {
         ret = 1;/* only before TLSv13 suites */