diff --git a/ChangeLog b/ChangeLog
index e36812e2..c5c9ef20 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2005-06-04  Alan Coopersmith  <alan.coopersmith@sun.com>
+
+	* configure.ac: 
+	Add --enable-secure-rpc flag and checks for needed functions for
+	Secure RPC ("SUN-DES-1") authentication method
+
 2005-05-27  Matthieu Herrb  <matthieu.herrb@laas.fr>
 
 	* nls/C/Makefile.am:
diff --git a/configure.ac b/configure.ac
index e0e22887..8ee999f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,6 +36,31 @@ AC_SUBST(XDMCP_LIBS)
 # Transport selection macro from xtrans.m4
 XTRANS_CONNECTION_FLAGS
 
+# Check for Secure RPC functions - must come after XTRANS_CONNECTION_FLAGS
+# so that any necessary networking libraries are already found
+AC_ARG_ENABLE(secure-rpc, 
+	AC_HELP_STRING([--enable-secure-rpc],[Enable Secure RPC]),
+        [SECURE_RPC=$enableval], [SECURE_RPC="try"])
+
+if test "x$SECURE_RPC" == "xyes" -o "x$SECURE_RPC" == "xtry" ; then
+	FOUND_SECURE_RPC="no"
+	AC_CHECK_FUNCS([authdes_seccreate authdes_create],
+			[FOUND_SECURE_RPC="yes"])
+	if test "x$FOUND_SECURE_RPC" == "xno" ; then
+		if test "x$SECURE_RPC" == "xyes" ; then
+	AC_MSG_ERROR([Secure RPC requested, but required functions not found])
+		fi	
+		SECURE_RPC="no"
+	else
+		SECURE_RPC="yes"
+	fi
+fi
+AC_MSG_CHECKING([if Secure RPC authentication ("SUN-DES-1") should be supported for X11 clients])
+if test "x$SECURE_RPC" == "xyes" ; then
+	AC_DEFINE(SECURE_RPC, 1, [Support Secure RPC ("SUN-DES-1") authentication for X11 clients])
+fi
+AC_MSG_RESULT($SECURE_RPC)
+
 # Check for dlopen
 AC_SEARCH_LIBS(dlopen,[dl svld])
 if test "x$ac_cv_search_dlopen" = xno; then