[pacman-dev] [PATCH] libmakepkg: reproducibilty for python packages

[Allan McRae]

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 at archlinux.org>
---

Despite effectively being a 1 line patch to add "export PYTHONHASHSEED=0",
I decided to add a libmakepkg submodule dedicated to reproducible packages.
This way anybody can drop in mdoules to test easily.

I'd like to include this for pacman-6.0.1.  It is a bit more than I would
usually like to include in a point release, but it is an easy win to for the 
reproducibile builds effort.

Any objections to including it?


 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 at 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 at 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
-- 
2.32.0