From 1c5a56884f8796ae29ffa46b3d8152c389ca0827 Mon Sep 17 00:00:00 2001
From: Allan McRae <allan@archlinux.org>
Date: Sun, 8 Aug 2021 22:49:32 +1000
Subject: [PATCH] libmakepkg: reproducibilty for python packages

Arch Linux has been setting PYTHONHASHSEED=0 to create deterministic
.pyc files.  After a thorough review by the Arch Security Team, setting
this variable was determined not to generated vulnerable .pyc files, as
when the loader loads the .pyc file and unmarshalls it, the internal
runtime will just populate the unordered data structures and use a new
runtime hash for them.

Signed-off-by: Allan McRae <allan@archlinux.org>
---
 scripts/libmakepkg/meson.build               |  1 +
 scripts/libmakepkg/reproducible.sh.in        | 29 ++++++++++++++++++++
 scripts/libmakepkg/reproducible/meson.build  | 17 ++++++++++++
 scripts/libmakepkg/reproducible/python.sh.in | 29 ++++++++++++++++++++
 4 files changed, 76 insertions(+)
 create mode 100644 scripts/libmakepkg/reproducible.sh.in
 create mode 100644 scripts/libmakepkg/reproducible/meson.build
 create mode 100644 scripts/libmakepkg/reproducible/python.sh.in

diff --git a/scripts/libmakepkg/meson.build b/scripts/libmakepkg/meson.build
index b0697f78..50eb905b 100644
--- a/scripts/libmakepkg/meson.build
+++ b/scripts/libmakepkg/meson.build
@@ -5,6 +5,7 @@ libmakepkg_modules = [
   { 'name' : 'lint_config',   'has_subdir' : true },
   { 'name' : 'lint_package',  'has_subdir' : true },
   { 'name' : 'lint_pkgbuild', 'has_subdir' : true },
+  { 'name' : 'reproducible',  'has_subdir' : true },
   { 'name' : 'source',        'has_subdir' : true },
   { 'name' : 'srcinfo',                           },
   { 'name' : 'tidy',          'has_subdir' : true },
diff --git a/scripts/libmakepkg/reproducible.sh.in b/scripts/libmakepkg/reproducible.sh.in
new file mode 100644
index 00000000..7db2a3cc
--- /dev/null
+++ b/scripts/libmakepkg/reproducible.sh.in
@@ -0,0 +1,29 @@
+#!/bin/bash
+#
+#   reproducible.sh - utilities for improving package reproducibility
+#
+#   Copyright (c) 2021 Pacman Development Team <pacman-dev@archlinux.org>
+#
+#   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 2 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/>.
+#
+
+[[ -n "$LIBMAKEPKG_REPRODUCIBLE_SH" ]] && return
+LIBMAKEPKG_REPRODUCIBLE_SH=1
+
+LIBRARY=${LIBRARY:-'@libmakepkgdir@'}
+
+
+for lib in "$LIBRARY/reproducible/"*.sh; do
+	source "$lib"
+done
diff --git a/scripts/libmakepkg/reproducible/meson.build b/scripts/libmakepkg/reproducible/meson.build
new file mode 100644
index 00000000..0738fe9c
--- /dev/null
+++ b/scripts/libmakepkg/reproducible/meson.build
@@ -0,0 +1,17 @@
+libmakepkg_module = 'reproducible'
+
+sources = [
+  'python.sh.in',
+]
+
+foreach src : sources
+  output_dir = join_paths(get_option('datadir'), 'makepkg', libmakepkg_module)
+
+  custom_target(
+    libmakepkg_module + '_' + src.underscorify(),
+    command : [ SCRIPT_EDITOR, '@INPUT@', '@OUTPUT@' ],
+    input : src,
+    output : '@BASENAME@',
+    install : true,
+    install_dir : output_dir)
+endforeach
diff --git a/scripts/libmakepkg/reproducible/python.sh.in b/scripts/libmakepkg/reproducible/python.sh.in
new file mode 100644
index 00000000..45fd4521
--- /dev/null
+++ b/scripts/libmakepkg/reproducible/python.sh.in
@@ -0,0 +1,29 @@
+#!/bin/bash
+#
+#   python.sh - creating reproducible python packages
+#
+#   Copyright (c) 2021 Pacman Development Team <pacman-dev@archlinux.org>
+#
+#   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 2 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/>.
+#
+
+[[ -n "$LIBMAKEPKG_REPRODUCIBLE_PYTHON_SH" ]] && return
+LIBMAKEPKG_REPRODUCIBLE_PYTHON_SH=1
+
+
+LIBRARY=${LIBRARY:-'@libmakepkgdir@'}
+
+
+# disable hash randomization when creating .pyc files
+export PYTHONHASHSEED=0