Merge branch 'bc/signed-objects-with-both-hashes'

Signed commits and tags now allow verification of objects, whose
two object names (one in SHA-1, the other in SHA-256) are both
signed.

* bc/signed-objects-with-both-hashes:
  gpg-interface: remove other signature headers before verifying
  ref-filter: hoist signature parsing
  commit: allow parsing arbitrary buffers with headers
  gpg-interface: improve interface for parsing tags
  commit: ignore additional signatures when parsing signed commits
  ref-filter: switch some uses of unsigned long to size_t

1 files changed, 25 insertions, 0 deletions

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 943a7d5c1d..400b83a49e 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -20,6 +20,13 @@ tag_exists () {
 	git show-ref --quiet --verify refs/tags/"$1"
 }
 
+test_expect_success 'setup' '
+	test_oid_cache <<-EOM
+	othersigheader sha1:gpgsig-sha256
+	othersigheader sha256:gpgsig
+	EOM
+'
+
 test_expect_success 'listing all tags in an empty tree should succeed' '
 	git tag -l &&
 	git tag
@@ -1374,6 +1381,24 @@ test_expect_success GPG \
 	'test_config gpg.program echo &&
 	 test_must_fail git tag -s -m tail tag-gpg-failure'
 
+# try to produce invalid signature
+test_expect_success GPG 'git verifies tag is valid with double signature' '
+	git tag -s -m tail tag-gpg-double-sig &&
+	git cat-file tag tag-gpg-double-sig >tag &&
+	othersigheader=$(test_oid othersigheader) &&
+	sed -ne "/^\$/q;p" tag >new-tag &&
+	cat <<-EOM >>new-tag &&
+	$othersigheader -----BEGIN PGP SIGNATURE-----
+	 someinvaliddata
+	 -----END PGP SIGNATURE-----
+	EOM
+	sed -e "1,/^tagger/d" tag >>new-tag &&
+	new_tag=$(git hash-object -t tag -w new-tag) &&
+	git update-ref refs/tags/tag-gpg-double-sig $new_tag &&
+	git verify-tag tag-gpg-double-sig &&
+	git fsck
+'
+
 # try to sign with bad user.signingkey
 test_expect_success GPGSM \
 	'git tag -s fails if gpgsm is misconfigured (bad key)' \