From de124dcafac678351366b0572938398ea7ae93e4 Mon Sep 17 00:00:00 2001
From: Guillem Jover <guillem@hadrons.org>
Date: Tue, 20 Feb 2024 04:28:01 +0100
Subject: [PATCH] build: Make digest function checks conditional on their use

The digest function checks where unconditionally requiring the functions
to exist or they would error out. But these functions are not required
on all systems, they depend on the ABI to be exposed.
---
 configure.ac | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 91e8fbf..a6e63db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,7 +44,7 @@ need_err=yes
 need_errc=yes
 need_fpurge=yes
 need_funopen=yes
-need_md5=yes
+need_md5=no
 need_name_from_id=yes
 need_nlist=yes
 need_progname=yes
@@ -169,20 +169,28 @@ AM_CONDITIONAL([HAVE_LIBTESTU01],
   [test "x$ac_cv_lib_testu01_unif01_CreateExternGenBits" = "xyes"])
 
 saved_LIBS="$LIBS"
-AC_SEARCH_LIBS([MD5Update], [md], [
-  AS_IF([test "x$ac_cv_search_MD5Update" != "xnone required"], [
-    MD5_LIBS="$MD5_LIBS $ac_cv_search_MD5Update"
-    need_transparent_libmd=yes
+AS_IF([test "$need_md5" = "yes"], [
+  AC_SEARCH_LIBS([MD5Update], [md], [
+    AS_IF([test "x$ac_cv_search_MD5Update" != "xnone required"], [
+      MD5_LIBS="$MD5_LIBS $ac_cv_search_MD5Update"
+      need_transparent_libmd=yes
+    ])
+  ], [
+    AC_MSG_ERROR([cannot find required MD5 functions in libc or libmd])
   ])
-], [
-  AC_MSG_ERROR([cannot find required MD5 functions in libc or libmd])
 ])
-AC_SEARCH_LIBS([SHA512Update], [md], [
-  AS_IF([test "x$ac_cv_search_SHA512Update" != "xnone required"], [
-    LIBBSD_LIBS="$LIBBSD_LIBS $ac_cv_search_SHA512Update"
+AS_IF([test "$need_arc4random" = "yes"], [
+  AC_CHECK_FUNCS([getentropy])
+
+  AS_IF([test "$ac_cv_func_getentropy" != "yes"], [
+    AC_SEARCH_LIBS([SHA512Update], [md], [
+      AS_IF([test "x$ac_cv_search_SHA512Update" != "xnone required"], [
+        LIBBSD_LIBS="$SHA512_LIBS $ac_cv_search_SHA512Update"
+      ])
+    ], [
+      AC_MSG_ERROR([cannot find required SHA-2 functions in libc or libmd])
+    ])
   ])
-], [
-  AC_MSG_ERROR([cannot find required SHA-2 functions in libc or libmd])
 ])
 LIBS="$saved_LIBS"