The test code should initialize impersonation level in a NT CreateAndX request. A SMB server may return BAD_IMPERSONATION_LEVEL (specified in SMB doc) if a random value is used.

The following code is taken from torture_samba3_checkfsp() in source4/torture/raw/samba3misc.c

        /* Open the directory */
        {
                union smb_open io;
                io.generic.level = RAW_OPEN_NTCREATEX;
                io.ntcreatex.in.flags = NTCREATEX_FLAGS_EXTENDED;
                io.ntcreatex.in.root_fid = 0;
                io.ntcreatex.in.security_flags = 0;
                io.ntcreatex.in.open_disposition = NTCREATEX_DISP_CREATE;
                io.ntcreatex.in.access_mask = SEC_RIGHTS_FILE_ALL;
                io.ntcreatex.in.alloc_size = 0;
                io.ntcreatex.in.file_attr = FILE_ATTRIBUTE_DIRECTORY;
                io.ntcreatex.in.share_access = NTCREATEX_SHARE_ACCESS_NONE;
                io.ntcreatex.in.open_disposition = NTCREATEX_DISP_OPEN;
                io.ntcreatex.in.create_options = 0;
                io.ntcreatex.in.impersonation = 0;
                io.ntcreatex.in.fname = dirname;
                status = smb_raw_open(cli->tree, mem_ctx, &io);
                if (!NT_STATUS_IS_OK(status)) {
                        d_printf("smb_open on the directory failed: %s\n",
                                 nt_errstr(status));
                        ret = false;
                        goto done;
                }
                fnum = io.ntcreatex.out.file.fnum;
        }

the code should set io.ntcreatex.in.impersonation to a value before calling smb_raw_open.