Enhance keyboxd to have new command for what keybox_set_flags does.

FWIW: There is actually a problem in the reference code: Having a
fixed size buffer inside a function and allowing the caller to provide
content at arbitrary length is bad coding style because the caller
needs to know internals of the called function (in a different source
file).

This is the original bug report to security at gnupg dated 2026-04-07:

Implemented for the Notepad and Sign/Encrypt Files. Can be tested with the certificates in T6702#216065.

In T8215#217199, @uwi wrote:

Anyway after reboot I could complete the update. The only think I had noticed was that Kleopatra's hair is blue now (it had been red in the past) ;-)

In T8215#216993, @ikloecker wrote:

By the way, your screenshot shows the wrong folder. That's why you didn't see the file that the error message mentions.

with VS-Desktop-3.3.97.11-Beta (GnuPG 2.2.54-beta9)

gpgsm does not support OAEP. Actually it does not make much sense to use this padding scheme at all. It has not advantage over PKCS#1. Thus I change this to a feature request to allow decryption using OAEP

Here is the change:

diff --git a/configure.ac b/configure.ac
index 30be86b5..ac2696e5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3073,7 +3073,8 @@ AC_CHECK_FUNCS(strtoul memmove stricmp atexit raise)
 AC_CHECK_FUNCS(strerror rand mmap getpagesize sysconf waitpid wait4)
 AC_CHECK_FUNCS(gettimeofday getrusage gethrtime clock_gettime syslog)
 AC_CHECK_FUNCS(syscall fcntl ftruncate flockfile getauxval elf_aux_info)
-AC_CHECK_FUNCS(explicit_bzero explicit_memset getentropy sysctlbyname)
+AC_CHECK_FUNCS(memset_explicit explicit_bzero explicit_memset)
+AC_CHECK_FUNCS(getentropy sysctlbyname)