app.c:440:65: error: implicit declaration of function 'UI_null' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
    if(ENGINE_ctrl_cmd(engine, "SET_USER_INTERFACE", 0, (void *)UI_null(), 0, 1) < 0) {
                                                                ^
app.c:440:57: error: cast to 'void *' from smaller integer type 'int' [-Werror,-Wint-to-void-pointer-cast]
    if(ENGINE_ctrl_cmd(engine, "SET_USER_INTERFACE", 0, (void *)UI_null(), 0, 1) < 0) {
                                                        ^~~~~~~~~~~~~~~~~
app.c:456:36: error: cast to 'UI_METHOD *' (aka 'struct ui_method_st *') from smaller integer type 'int' [-Werror,-Wint-to-pointer-cast]
                                   (UI_METHOD *)UI_null(),
                                   ^~~~~~~~~~~~~~~~~~~~~~
3 errors generated.
gmake[5]: *** [Makefile:625: libxmlsec1_openssl_la-app.lo] Error 1
gmake[5]: *** Waiting for unfinished jobs....
mv -f .deps/libxmlsec1_openssl_la-bn.Tpo .deps/libxmlsec1_openssl_la-bn.Plo
gmake[5]: Leaving directory '/usr/obj/usr/ports/security/xmlsec1/work/xmlsec1-1.2.34/src/openssl'
gmake[4]: *** [Makefile:688: all-recursive] Error 1
gmake[4]: Leaving directory '/usr/obj/usr/ports/security/xmlsec1/work/xmlsec1-1.2.34/src'
gmake[3]: *** [Makefile:742: all-recursive] Error 1
gmake[3]: Leaving directory '/usr/obj/usr/ports/security/xmlsec1/work/xmlsec1-1.2.34'
gmake[2]: *** [Makefile:560: all] Error 2
gmake[2]: Leaving directory '/usr/obj/usr/ports/security/xmlsec1/work/xmlsec1-1.2.34'
===> Compilation failed unexpectedly.