@@ -65,7 +65,7 @@ download_git() {
}
extract_git() {
- local netfile=$1
+ local netfile=$1 tagname
local fragment=$(get_uri_fragment "$netfile")
local repo=$(get_filename "$netfile")
@@ -110,6 +110,15 @@ extract_git() {
esac
fi
+ if [[ ${fragment%%=*} = tag ]]; then
+ tagname="$(git tag -l --format='%(tag)' "$ref")"
+ if [[ -n $tagname && $tagname != $ref ]]; then
+ error "$(gettext "Failure while checking out version %s, the git tag has been forged")" "$ref"
+ plain "$(gettext "Aborting...")"
+ exit 1
+ fi
+ fi
+
if [[ $ref != "origin/HEAD" ]] || (( updating )) ; then
if ! git checkout --force --no-track -B makepkg $ref; then
error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "git"
As per https://lists.archlinux.org/pipermail/arch-general/2017-July/043876.html git doesn't check that the tag name matches what an annotated tag object *thinks* it should be called. This is a bit of a theoretical attack and some would argue that we should always use commits since upstream can legitimately change a tag, but nevertheless this can result in a downgrade attack if the git download transport was manipulated or the upstream repository hacked. So, check the tag blob to make sure the tag actually matches the name we used for `git checkout`. This really should be fixed in git itself, rather than forcing all downstream users of git verify-tag to implement their own checks, but the git developers disagree, see the discussion surrounding https://public-inbox.org/git/xmqqk2hzldx8.fsf@gitster.mtv.corp.google.com/ Signed-off-by: Eli Schwartz <eschwartz@archlinux.org> --- scripts/libmakepkg/source/git.sh.in | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)