+PKG_CHECK_MODULES([OPENSSL], [openssl])
+AC_SUBST([OPENSSL_CFLAGS])
+AC_SUBST([OPENSSL_LIBS])
+
+AC_CHECK_HEADERS([gssapi/gssapi.h gssapi/gssapi_ext.h gssapi/gssapi_krb5.h],
+ ,[AC_MSG_ERROR([Could not find GSSAPI headers])])
+AC_CHECK_HEADERS([gssapi/gssapi_ntlmssp.h])