Add function to generate random identifier
The function is a wrapper on top of getrandom() (if available via glibc) or
corresponding syscall. If neither is available than failure is always
returned.
It's intended to generate small random data good enough for session
identifiers and keys. To generate long-term cryptographic keys it's
better to use special crypto libraries (like GnuTLS for example)
instead.
As an example it's used to replace old insecure random number generator
in osmo-auc-gen utility.
Change-Id: I0241b814ea4c4ce1458f7ad76e31d390383c2048
Related: OS#1694
diff --git a/configure.ac b/configure.ac
index 33c151e..d9390cf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -73,6 +73,9 @@
AC_PATH_PROG(DOXYGEN,doxygen,false)
AM_CONDITIONAL(HAVE_DOXYGEN, test $DOXYGEN != false && test "x$doxygen" = "xyes")
+# check for syscal fallback on glibc < 2.25 - can be removed once glibc version requirement is bumped
+AC_CHECK_DECLS([SYS_getrandom], [], [], [[#include <sys/syscall.h>]])
+
# The following test is taken from WebKit's webkit.m4
saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fvisibility=hidden "