[pacman-dev] [PATCH 3/3] makepkg: Introduce validpgpkeys array

[Thomas Bächler]

If validpgpkeys is set in the PKGBUILD, signature checking fails if
the fingerprint of the key used to create the signature is not listed
in the array.

The key's trust value is ignored.
---
 doc/PKGBUILD.5.txt    |  7 +++++++
 scripts/makepkg.sh.in | 16 ++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/doc/PKGBUILD.5.txt b/doc/PKGBUILD.5.txt
index 50d8347..7a1e924 100644
--- a/doc/PKGBUILD.5.txt
+++ b/doc/PKGBUILD.5.txt
@@ -128,6 +128,13 @@ Files in the source array with extensions `.sig`, `.sign` or, `.asc` are
 recognized by makepkg as PGP signatures and will be automatically used to verify
 the integrity of the corresponding source file.
 
+*validpgpkeys (array)*::
+	An array of PGP fingerprints. If this array is non-empty, makepkg will
+	only accept signatures from the keys listed here and will ignore the
+	trust values from the keyring.
++
+Fingerprints must be uppercase and must not contain whitespace characters.
+
 *noextract (array)*::
 	An array of file names corresponding to those from the source array. Files
 	listed here will not be extracted with the rest of the source files. This
diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
index 015bdd7..6eb6d11 100644
--- a/scripts/makepkg.sh.in
+++ b/scripts/makepkg.sh.in
@@ -1244,6 +1244,15 @@ check_checksums() {
 	fi
 }
 
+is_valid_pgpkey() {
+	local pubkey
+
+	pubkey=$(grep VALIDSIG "$statusfile" | sed -nr 's/.* VALIDSIG ([A-Z0-9]*) .*/\1/p;')
+	echo "$pubkey"
+	in_array "$pubkey" ${validpgpkeys[@]}
+	return $?
+}
+
 check_pgpsigs() {
 	(( SKIPPGPCHECK )) && return 0
 	! source_has_signatures && return 0
@@ -1303,9 +1312,12 @@ check_pgpsigs() {
 			if grep -q "REVKEYSIG" "$statusfile"; then
 				printf '%s (%s)' "$(gettext "FAILED")" "$(gettext "the key has been revoked.")" >&2
 				errors=1
-			elif grep -q -e "TRUST_UNDEFINED" -e "TRUST_NEVER" "$statusfile"; then
+			elif (( ${#validpgpkeys[@]} == 0 )) && grep -q -e "TRUST_UNDEFINED" -e "TRUST_NEVER" "$statusfile"; then
 				printf '%s (%s)' "$(gettext "FAILED")" "$(gettext "the key is not trusted")" >&2
 				errors=1
+			elif (( ${#validpgpkeys[@]} > 0 )) && ! pubkey=$(is_valid_pgpkey "$statusfile"); then
+				printf "%s (%s $pubkey)" "$(gettext "FAILED")" "$(gettext "invalid key")"
+				errors=1
 			else
 				printf '%s' "$(gettext "Passed")" >&2
 				if grep -q "EXPSIG" "$statusfile"; then
@@ -2810,7 +2822,7 @@ fi
 
 unset pkgname pkgbase pkgver pkgrel epoch pkgdesc url license groups provides
 unset md5sums replaces depends conflicts backup source install changelog build
-unset makedepends optdepends options noextract
+unset makedepends optdepends options noextract validpgpkeys
 
 BUILDFILE=${BUILDFILE:-$BUILDSCRIPT}
 if [[ ! -f $BUILDFILE ]]; then
-- 
1.9.0