From 658056aee65aacb27c3f08fb2f0517d7d140f56d Mon Sep 17 00:00:00 2001
From: xnumad <34810600+xnumad@users.noreply.github.com>
Date: Thu, 8 Feb 2024 12:18:26 +0100
Subject: [PATCH] Generate secret_key at compilation

Requires Python >=3.6, which is already EOL, so not noteworthy
https://github.com/RIOT-OS/RIOT/pull/20370#discussion_r1498370589
---
 sys/net/gnrc/Makefile.dep | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sys/net/gnrc/Makefile.dep b/sys/net/gnrc/Makefile.dep
index 8e36e56ecdb29..f521fec1a3efa 100644
--- a/sys/net/gnrc/Makefile.dep
+++ b/sys/net/gnrc/Makefile.dep
@@ -441,6 +441,21 @@ ifneq (,$(filter gnrc_ipv6_nib,$(USEMODULE)))
   USEMODULE += random
 endif
 
+#This checks if the option is being set via Kconfig or CFLAGS
+ifneq (,$(or $(CONFIG_GNRC_IPV6_STABLE_PRIVACY),$(filter -DCONFIG_GNRC_IPV6_STABLE_PRIVACY=1,$(CFLAGS))))
+  # Set another macro that is needed for this option.
+
+  ##prepare value
+  stable_privacy_secret_key != python3 -c "import secrets; print(','.join([f'0x{byte:02x}' for byte in secrets.token_bytes(16)]))"
+
+  ##set macro
+  CFLAGS += -DSTABLE_PRIVACY_SECRET_KEY=$(stable_privacy_secret_key)
+
+  # dependencies
+  USEMODULE += hashes ##include "hashes/sha256.h"
+  USEMODULE += ztimer_msec
+endif
+
 ifneq (,$(filter gnrc_udp,$(USEMODULE)))
   DEFAULT_MODULE += auto_init_gnrc_udp
   USEMODULE += gnrc_nettype_udp