Initial commit

package/system/urandom-seed/Makefile

@@ -0,0 +1,32 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=urandom-seed
+PKG_RELEASE:=3
+PKG_LICENSE:=GPL-2.0-only
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/urandom-seed
+  SECTION:=base
+  CATEGORY:=Base system
+  DEPENDS:=+getrandom
+  TITLE:=/etc/urandom.seed handling for OpenWrt
+  URL:=https://openwrt.org/
+endef
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+endef
+
+define Build/Quilt
+endef
+
+define Build/Compile/Default
+endef
+Build/Compile = $(Build/Compile/Default)
+
+define Package/urandom-seed/install
+	$(CP) ./files/* $(1)/
+endef
+
+$(eval $(call BuildPackage,urandom-seed))

package/system/urandom-seed/files/etc/init.d/urandom_seed

@@ -0,0 +1,12 @@
+#!/bin/sh /etc/rc.common
+
+START=99
+USE_PROCD=1
+
+start_service() {
+    procd_open_instance "urandom_seed"
+    procd_set_param command "/sbin/urandom_seed"
+    procd_set_param stdout 1
+    procd_set_param stderr 1
+    procd_close_instance
+}

package/system/urandom-seed/files/lib/preinit/81_urandom_seed

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+log_urandom_seed() {
+    echo "urandom-seed: $1" > /dev/kmsg
+}
+
+_do_urandom_seed() {
+    [ -f "$1" ] || { log_urandom_seed "Seed file not found ($1)"; return; }
+    [ -O "$1" -a -G "$1" -a ! -x "$1" ] || { log_urandom_seed "Wrong owner / permissions for $1"; return; }
+
+    log_urandom_seed "Seeding with $1"
+    cat "$1" > /dev/urandom
+}
+
+do_urandom_seed() {
+    [ -c /dev/urandom ] || { log_urandom_seed "Something is wrong with /dev/urandom"; return; }
+
+    _do_urandom_seed "/etc/urandom.seed"
+
+    SEED="$(uci -q get system.@system[0].urandom_seed)"
+    [ "${SEED:0:1}" = "/" -a "$SEED" != "/etc/urandom.seed" ] && _do_urandom_seed "$SEED"
+}
+
+boot_hook_add preinit_main do_urandom_seed

package/system/urandom-seed/files/sbin/urandom_seed

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -e
+
+trap '[ "$?" -eq 0 ] || echo "An error occured" >&2' EXIT
+
+save() {
+    touch "$1.tmp"
+    chown root:root "$1.tmp"
+    chmod 600 "$1.tmp"
+    getrandom 512 > "$1.tmp"
+    mv "$1.tmp" "$1"
+    echo "Seed saved ($1)"
+}
+
+SEED="$(uci -q get system.@system[0].urandom_seed || true)"
+[ "${SEED:0:1}" = "/" ] && save "$SEED"
+
+SEED=/etc/urandom.seed
+[ ! -f $SEED ] && save "$SEED"
+true