1 #!/bin/sh
2 # Copyright (c) 2014-2019 The Limenka developers
3 # Distributed under the MIT software license, see the accompanying
4 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 6 export LC_ALL=C
7 INPUT=$(cat /dev/stdin)
8 if [ "$LIMENKA_VERIFY_COMMITS_ALLOW_SHA1" = 1 ]; then
9 printf '%s\n' "$INPUT" | gpg --trust-model always "$@" 2>/dev/null
10 exit $?
11 else
12 # Note how we've disabled SHA1 with the --weak-digest option, disabling
13 # signatures - including selfsigs - that use SHA1. While you might think that
14 # collision attacks shouldn't be an issue as they'd be an attack on yourself,
15 # in fact because what's being signed is a commit object that's
16 # semi-deterministically generated by untrusted input (the pull-req) in theory
17 # an attacker could construct a pull-req that results in a commit object that
18 # they've created a collision for. Not the most likely attack, but preventing
19 # it is pretty easy so we do so as a "belt-and-suspenders" measure.
20 for LINE in $(gpg --version); do
21 case "$LINE" in
22 "gpg (GnuPG) 1.4.1"*|"gpg (GnuPG) 2.0."*)
23 echo "Please upgrade to at least gpg 2.1.10 to check for weak signatures" > /dev/stderr
24 printf '%s\n' "$INPUT" | gpg --trust-model always "$@" 2>/dev/null
25 exit $?
26 ;;
27 # We assume if you're running 2.1+, you're probably running 2.1.10+
28 # gpg will fail otherwise
29 # We assume if you're running 1.X, it is either 1.4.1X or 1.4.20+
30 # gpg will fail otherwise
31 esac
32 done
33 printf '%s\n' "$INPUT" | gpg --trust-model always --weak-digest sha1 "$@" 2>/dev/null
34 exit $?
35 fi
36