Format Windows error message in Unicode

- We assume that all text passed to the management interface and written to log file are in Unicode (UTF-8). This is broken by the use of the ANSI version of FormatMessage() for Windows error messages. Fix by using FormatMessageW() and converting the UTF-16 result to UTF-8. v2: assign return value of FormatMessageW() to DWORD, not int Github: fixes OpenVPN/openvpn#319 Signed-off-by: Selva Nair <[email protected]> Acked-by: Frank Lichtenheld <[email protected]> Message-Id: <[email protected]> URL: https://www.mail-archive.com/[email protected]/msg26598.html Signed-off-by: Gert Doering <[email protected]>
cron2 · May 4, 2023 · fed6764 · fed6764
1 parent 7b21c69
commit fed6764
Showing 1 changed file with 10 additions and 5 deletions.
diff --git a/src/openvpn/error.c b/src/openvpn/error.c
@@ -970,19 +970,24 @@ strerror_win32(DWORD errnum, struct gc_arena *gc)
 
     /* format a windows error message */
     {
-        char message[256];
+        wchar_t wmessage[256];
+        char *message = NULL;
         struct buffer out = alloc_buf_gc(256, gc);
-        const int status =  FormatMessage(
+        const DWORD status =  FormatMessageW(
             FORMAT_MESSAGE_IGNORE_INSERTS
             | FORMAT_MESSAGE_FROM_SYSTEM
             | FORMAT_MESSAGE_ARGUMENT_ARRAY,
             NULL,
             errnum,
             0,
-            message,
-            sizeof(message),
+            wmessage,
+            SIZE(wmessage),
             NULL);
-        if (!status)
+        if (status)
+        {
+            message = utf16to8(wmessage, gc);
+        }
+        if (!status || !message)
         {
             buf_printf(&out, "[Unknown Win32 Error]");
         }