diff --git a/cf/auth-modules.m4 b/cf/auth-modules.m4
new file mode 100644
index 000000000..7fbbac94e
--- /dev/null
+++ b/cf/auth-modules.m4
@@ -0,0 +1,27 @@
+dnl $Id$
+dnl
+dnl Figure what authentication modules should be built
+
+AC_DEFUN(AC_AUTH_MODULES,[
+AC_MSG_CHECKING(which authentication modules should be built)
+
+LIB_AUTH_SUBDIRS=
+
+if test "$ac_cv_header_siad_h" = yes; then
+	LIB_AUTH_SUBDIRS="$LIB_AUTH_SUBDIRS sia"
+fi
+
+if test "$ac_cv_header_security_pam_modules_h" = yes -a "$enable_shared" = yes; then
+	LIB_AUTH_SUBDIRS="$LIB_AUTH_SUBDIRS pam"
+fi
+
+case "${host}" in
+changequote(,)dnl
+*-*-irix[56]*) LIB_AUTH_SUBDIRS="$LIB_AUTH_SUBDIRS afskauthlib" ;;
+changequote([,])dnl
+esac
+
+AC_MSG_RESULT($LIB_AUTH_SUBDIRS)
+
+AC_SUBST(LIB_AUTH_SUBDIRS)dnl
+])