[tor-commits] [torsocks/master] Add hardening compile and linker flags
dgoulet at torproject.org
dgoulet at torproject.org
Fri Apr 4 22:40:27 UTC 2014
commit 006178a0362b08252fccf5e1a7981e1f089616d1
Author: David Goulet <dgoulet at ev0ke.net>
Date: Tue Nov 12 00:21:09 2013 -0500
Add hardening compile and linker flags
Signed-off-by: David Goulet <dgoulet at ev0ke.net>
---
.gitignore | 4 ++-
config/ax_check_compile_flag.m4 | 72 +++++++++++++++++++++++++++++++++++++++
config/ax_check_link_flag.m4 | 71 ++++++++++++++++++++++++++++++++++++++
configure.ac | 18 ++++++++++
4 files changed, 164 insertions(+), 1 deletion(-)
diff --git a/.gitignore b/.gitignore
index 9739a6f..eb70007 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,7 +32,9 @@ missing
stamp-h1
tags
-config/*
+config/
+!config/ax_check_compile_flag.m4
+!config/ax_check_link_flag .m4
doc/torsocks.1
doc/torsocks.8
diff --git a/config/ax_check_compile_flag.m4 b/config/ax_check_compile_flag.m4
new file mode 100644
index 0000000..c3a8d69
--- /dev/null
+++ b/config/ax_check_compile_flag.m4
@@ -0,0 +1,72 @@
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the current language's compiler
+# or gives an error. (Warnings, however, are ignored)
+#
+# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+# success/failure.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod at gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans at gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 2
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+ ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+ _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS
diff --git a/config/ax_check_link_flag.m4 b/config/ax_check_link_flag.m4
new file mode 100644
index 0000000..e2d0d36
--- /dev/null
+++ b/config/ax_check_link_flag.m4
@@ -0,0 +1,71 @@
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the linker or gives an error.
+# (Warnings, however, are ignored)
+#
+# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+# success/failure.
+#
+# If EXTRA-FLAGS is defined, it is added to the linker's default flags
+# when the check is done. The check is thus made with the flags: "LDFLAGS
+# EXTRA-FLAGS FLAG". This can for example be used to force the linker to
+# issue an error when a bad flag is given.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod at gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans at gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 2
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+ ax_check_save_flags=$LDFLAGS
+ LDFLAGS="$LDFLAGS $4 $1"
+ AC_LINK_IFELSE([AC_LANG_PROGRAM()],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ LDFLAGS=$ax_check_save_flags])
+AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS
diff --git a/configure.ac b/configure.ac
index 7cdf462..3cfda8f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -144,6 +144,24 @@ AC_SUBST(TESTLDFLAGS)
# Version information for libtorsocks
TORSOCKSLDFLAGS="$LDFLAGS -version-info 1:0:0"
+# Check for the gcc hardening flags.
+AX_CHECK_COMPILE_FLAG([-fPIE],[CFLAGS="$CFLAGS -fPIE"],[],[])
+AX_CHECK_COMPILE_FLAG([-fwrapv],[CFLAGS="$CFLAGS -fwrapv"],[],[])
+AX_CHECK_COMPILE_FLAG([--param ssp-buffer-size=1],
+ [CFLAGS="$CFLAGS --param ssp-buffer-size=1"],[],[])
+AX_CHECK_COMPILE_FLAG([-fstack-protector-all],
+ [CFLAGS="$CFLAGS -fstack-protector-all"],[],[]
+)
+AX_CHECK_COMPILE_FLAG([-fno-strict-overflow],
+ [CFLAGS="$CFLAGS -fno-strict-overflow"],[],[]
+)
+
+dnl Add hardening linker flags
+AX_CHECK_LINK_FLAG([-pie],[LDFLAGS="$LDFLAGS -pie"],[],[])
+AX_CHECK_LINK_FLAG([-z relro],[LDFLAGS="$LDFLAGS -z relro"],[],[])
+AX_CHECK_LINK_FLAG([-z now],[LDFLAGS="$LDFLAGS -z now"],[],[])
+LDFLAGS="$LDFLAGS -D_FORTIFY_SOURCE=2"
+
dnl Linker checks for Mac OSX, which uses DYLD_INSERT_LIBRARIES
dnl instead of LD_PRELOAD
case "$host_os" in
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