crypto: Use getrandom for qcrypto_random_bytes

Prefer it to direct use of /dev/urandom.

Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 17 insertions, 1 deletions

diff --git a/configure b/configure
index 54fa78c4dc..f3526a5bca 100755
--- a/configure
+++ b/configure
@@ -5816,6 +5816,20 @@ if compile_prog "" "" ; then
 fi
 
 ##########################################
+# check for getrandom()
+
+have_getrandom=no
+cat > $TMPC << EOF
+#include <sys/random.h>
+int main(void) {
+    return getrandom(0, 0, GRND_NONBLOCK);
+}
+EOF
+if compile_prog "" "" ; then
+    have_getrandom=yes
+fi
+
+##########################################
 # checks for sanitizers
 
 have_asan=no
@@ -7204,7 +7218,9 @@ fi
 if test "$have_utmpx" = "yes" ; then
   echo "HAVE_UTMPX=y" >> $config_host_mak
 fi
-
+if test "$have_getrandom" = "yes" ; then
+  echo "CONFIG_GETRANDOM=y" >> $config_host_mak
+fi
 if test "$ivshmem" = "yes" ; then
   echo "CONFIG_IVSHMEM=y" >> $config_host_mak
 fi