test for and use system explicit_bzero if it exists

ok beck@ guenther@

2 files changed, 10 insertions, 1 deletions

diff --git a/configure.ac.tpl b/configure.ac.tpl
index 84d2f69..ac66565 100644
--- a/configure.ac.tpl
+++ b/configure.ac.tpl
@@ -105,6 +105,11 @@ AC_CHECK_FUNC(strtonum,[AC_SEARCH_LIBS(write,, [NO_STRTONUM=],
 AC_SUBST(NO_STRTONUM)
 AM_CONDITIONAL(NO_STRTONUM, test "x$NO_STRTONUM" = "xyes")
 
+AC_CHECK_FUNC(explicit_bzero,[AC_SEARCH_LIBS(write,, [NO_EXPLICIT_BZERO=],
+                          [NO_EXPLICIT_BZERO=yes])], [NO_EXPLICIT_BZERO=yes])
+AC_SUBST(NO_EXPLICIT_BZERO)
+AM_CONDITIONAL(NO_EXPLICIT_BZERO, test "x$NO_EXPLICIT_BZERO" = "xyes")
+
 AC_CHECK_FUNC(getauxval, AC_DEFINE(HAVE_GETAUXVAL))
 
 AC_CHECK_FUNC(funopen, AC_DEFINE(HAVE_FUNOPEN))
diff --git a/crypto/Makefile.am.tpl b/crypto/Makefile.am.tpl
index ac87a77..6e1c423 100644
--- a/crypto/Makefile.am.tpl
+++ b/crypto/Makefile.am.tpl
@@ -14,7 +14,11 @@ noinst_LTLIBRARIES = libcompat.la libcompatnoopt.la
 
 # compatibility functions that need to be built without optimizations
 libcompatnoopt_la_CFLAGS = -O0
-libcompatnoopt_la_SOURCES = compat/explicit_bzero.c
+libcompatnoopt_la_SOURCES =
+
+if NO_EXPLICIT_BZERO
+libcompatnoopt_la_SOURCES += compat/explicit_bzero.c
+endif
 
 # other compatibility functions
 libcompat_la_CFLAGS = $(CFLAGS) $(USER_CFLAGS)