openwrtv4/include/hardening.mk
Julien Dusser df0bd42fde build: add hardened builds with PIE (ASLR) support
Introduce a configuration option to build a "hardened" OpenWrt with
ASLR PIE support.

Add new option PKG_ASLR_PIE to enable Address Space Layout Randomization (ASLR)
by building Position Independent Executables (PIE). This new option protects
against "return-to-text" attacks.

Busybox need a special care, link is done with ld, not gcc, leading to
unknown flags. Set BUSYBOX_DEFAULT_PIE instead and disable PKG_ASLR_PIE.

If other failing packages were found, PKG_ASLR_PIE:=0 should be added to
their Makefiles.

Original Work by: Yongkui Han <yonhan@cisco.com>
Signed-off-by: Julien Dusser <julien.dusser@free.fr>
2018-01-27 16:46:45 +01:00

57 lines
1.4 KiB
Makefile

#
# Copyright (C) 2015 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#
PKG_CHECK_FORMAT_SECURITY ?= 1
PKG_ASLR_PIE ?= 1
PKG_SSP ?= 1
PKG_FORTIFY_SOURCE ?= 1
PKG_RELRO ?= 1
ifdef CONFIG_PKG_CHECK_FORMAT_SECURITY
ifeq ($(strip $(PKG_CHECK_FORMAT_SECURITY)),1)
TARGET_CFLAGS += -Wformat -Werror=format-security
endif
endif
ifdef CONFIG_PKG_ASLR_PIE
ifeq ($(strip $(PKG_ASLR_PIE)),1)
TARGET_CFLAGS += -fPIC
TARGET_LDFLAGS += -specs=$(INCLUDE_DIR)/hardened-ld-pie.specs
endif
endif
ifdef CONFIG_PKG_CC_STACKPROTECTOR_REGULAR
ifeq ($(strip $(PKG_SSP)),1)
TARGET_CFLAGS += -fstack-protector
endif
endif
ifdef CONFIG_PKG_CC_STACKPROTECTOR_STRONG
ifeq ($(strip $(PKG_SSP)),1)
TARGET_CFLAGS += -fstack-protector-strong
endif
endif
ifdef CONFIG_PKG_FORTIFY_SOURCE_1
ifeq ($(strip $(PKG_FORTIFY_SOURCE)),1)
TARGET_CFLAGS += -D_FORTIFY_SOURCE=1
endif
endif
ifdef CONFIG_PKG_FORTIFY_SOURCE_2
ifeq ($(strip $(PKG_FORTIFY_SOURCE)),1)
TARGET_CFLAGS += -D_FORTIFY_SOURCE=2
endif
endif
ifdef CONFIG_PKG_RELRO_PARTIAL
ifeq ($(strip $(PKG_RELRO)),1)
TARGET_CFLAGS += -Wl,-z,relro
TARGET_LDFLAGS += -zrelro
endif
endif
ifdef CONFIG_PKG_RELRO_FULL
ifeq ($(strip $(PKG_RELRO)),1)
TARGET_CFLAGS += -Wl,-z,now -Wl,-z,relro
TARGET_LDFLAGS += -znow -zrelro
endif
endif