fsck: consider gpgsig headers expected in tags

When we're creating a tag, we want to make sure that gpgsig and
gpgsig-sha256 headers are allowed for the commit.  The default fsck
behavior is to ignore the fact that they're left over, but some of our
tests enable strict checking which flags them nonetheless.  Add
improved checking for these headers as well as documentation and several
tests.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/fsck-msgids.adoc b/Documentation/fsck-msgids.adoc
index 0ba4f9a..52d9a8a 100644 (file)
--- a/Documentation/fsck-msgids.adoc
+++ b/Documentation/fsck-msgids.adoc
@@ -10,6 +10,12 @@
 `badFilemode`::
        (INFO) A tree contains a bad filemode entry.
 
+`badGpgsig`::
+       (ERROR) A tag contains a bad (truncated) signature (e.g., `gpgsig`) header.
+
+`badHeaderContinuation`::
+       (ERROR) A continuation header (such as for `gpgsig`) is unexpectedly truncated.
+
 `badName`::
        (ERROR) An author/committer name is empty.
 

diff --git a/fsck.c b/fsck.c
index 171b424..341e100 100644 (file)
--- a/fsck.c
+++ b/fsck.c
@@ -1067,6 +1067,24 @@ int fsck_tag_standalone(const struct object_id *oid, const char *buffer,
        else
                ret = fsck_ident(&buffer, oid, OBJ_TAG, options);
 
+       if (buffer < buffer_end && (skip_prefix(buffer, "gpgsig ", &buffer) || skip_prefix(buffer, "gpgsig-sha256 ", &buffer))) {
+               eol = memchr(buffer, '\n', buffer_end - buffer);
+               if (!eol) {
+                       ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_GPGSIG, "invalid format - unexpected end after 'gpgsig' or 'gpgsig-sha256' line");
+                       goto done;
+               }
+               buffer = eol + 1;
+
+               while (buffer < buffer_end && starts_with(buffer, " ")) {
+                       eol = memchr(buffer, '\n', buffer_end - buffer);
+                       if (!eol) {
+                               ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_HEADER_CONTINUATION, "invalid format - unexpected end in 'gpgsig' or 'gpgsig-sha256' continuation line");
+                               goto done;
+                       }
+                       buffer = eol + 1;
+               }
+       }
+
        if (buffer < buffer_end && !starts_with(buffer, "\n")) {
                /*
                 * The verify_headers() check will allow

diff --git a/fsck.h b/fsck.h
index dd7df3d..c26616d 100644 (file)
--- a/fsck.h
+++ b/fsck.h
@@ -25,9 +25,11 @@ enum fsck_msg_type {
        FUNC(NUL_IN_HEADER, FATAL) \
        FUNC(UNTERMINATED_HEADER, FATAL) \
        /* errors */ \
+       FUNC(BAD_HEADER_CONTINUATION, ERROR) \
        FUNC(BAD_DATE, ERROR) \
        FUNC(BAD_DATE_OVERFLOW, ERROR) \
        FUNC(BAD_EMAIL, ERROR) \
+       FUNC(BAD_GPGSIG, ERROR) \
        FUNC(BAD_NAME, ERROR) \
        FUNC(BAD_OBJECT_SHA1, ERROR) \
        FUNC(BAD_PACKED_REF_ENTRY, ERROR) \

diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 5ae86c4..c4b651c 100755 (executable)
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -454,6 +454,60 @@ test_expect_success 'tag with NUL in header' '
        test_grep "error in tag $tag.*unterminated header: NUL at offset" out
 '
 
+test_expect_success 'tag accepts gpgsig header even if not validly signed' '
+       test_oid_cache <<-\EOF &&
+       header sha1:gpgsig-sha256
+       header sha256:gpgsig
+       EOF
+       header=$(test_oid header) &&
+       sha=$(git rev-parse HEAD) &&
+       cat >good-tag <<-EOF &&
+       object $sha
+       type commit
+       tag good
+       tagger T A Gger <tagger@example.com> 1234567890 -0000
+       $header -----BEGIN PGP SIGNATURE-----
+        Not a valid signature
+        -----END PGP SIGNATURE-----
+
+       This is a good tag.
+       EOF
+
+       tag=$(git hash-object --literally -t tag -w --stdin <good-tag) &&
+       test_when_finished "remove_object $tag" &&
+       git update-ref refs/tags/good $tag &&
+       test_when_finished "git update-ref -d refs/tags/good" &&
+       git -c fsck.extraHeaderEntry=error fsck --tags
+'
+
+test_expect_success 'tag rejects invalid headers' '
+       test_oid_cache <<-\EOF &&
+       header sha1:gpgsig-sha256
+       header sha256:gpgsig
+       EOF
+       header=$(test_oid header) &&
+       sha=$(git rev-parse HEAD) &&
+       cat >bad-tag <<-EOF &&
+       object $sha
+       type commit
+       tag good
+       tagger T A Gger <tagger@example.com> 1234567890 -0000
+       $header -----BEGIN PGP SIGNATURE-----
+        Not a valid signature
+        -----END PGP SIGNATURE-----
+       junk
+
+       This is a bad tag with junk at the end of the headers.
+       EOF
+
+       tag=$(git hash-object --literally -t tag -w --stdin <bad-tag) &&
+       test_when_finished "remove_object $tag" &&
+       git update-ref refs/tags/bad $tag &&
+       test_when_finished "git update-ref -d refs/tags/bad" &&
+       test_must_fail git -c fsck.extraHeaderEntry=error fsck --tags 2>out &&
+       test_grep "error in tag $tag.*invalid format - extra header" out
+'
+
 test_expect_success 'cleaned up' '
        git fsck >actual 2>&1 &&
        test_must_be_empty actual