path: root/builtin
diff options
authorHans Jerry Illikainen <>2020-03-04 11:48:04 (GMT)
committerJunio C Hamano <>2020-03-15 16:46:28 (GMT)
commit67948981983b336eab2fa7e6a0e125d529391dfc (patch)
tree6365d127be157a4ae8061186e0a156cce7497014 /builtin
parentf1e3df316992d32b17ee27385e4c644ef7b66cc1 (diff)
gpg-interface: prefer check_signature() for GPG verification
This commit refactors the use of verify_signed_buffer() outside of gpg-interface.c to use check_signature() instead. It also turns verify_signed_buffer() into a file-local function since it's now only invoked internally by check_signature(). There were previously two globally scoped functions used in different parts of Git to perform GPG signature verification: verify_signed_buffer() and check_signature(). Now only check_signature() is used. The verify_signed_buffer() function doesn't guard against duplicate signatures as described by Michał Górny [1]. Instead it only ensures a non-erroneous exit code from GPG and the presence of at least one GOODSIG status field. This stands in contrast with check_signature() that returns an error if more than one signature is encountered. The lower degree of verification makes the use of verify_signed_buffer() problematic if callers don't parse and validate the various parts of the GPG status message themselves. And processing these messages seems like a task that should be reserved to gpg-interface.c with the function check_signature(). Furthermore, the use of verify_signed_buffer() makes it difficult to introduce new functionality that relies on the content of the GPG status lines. Now all operations that does signature verification share a single entry point to gpg-interface.c. This makes it easier to propagate changed or additional functionality in GPG signature verification to all parts of Git, without having odd edge-cases that don't perform the same degree of verification. [1] Signed-off-by: Hans Jerry Illikainen <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'builtin')
1 files changed, 7 insertions, 4 deletions
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 736f666..172dfbd 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -494,6 +494,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
enum object_type type;
unsigned long size, len;
char *buf = read_object_file(oid, &type, &size);
+ struct signature_check sigc = { 0 };
struct strbuf sig = STRBUF_INIT;
if (!buf || type != OBJ_TAG)
@@ -502,10 +503,12 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
if (size == len)
; /* merely annotated */
- else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
- if (!sig.len)
- strbuf_addstr(&sig, "gpg verification failed.\n");
- }
+ else if (check_signature(buf, len, buf + len, size - len, &sigc) &&
+ !sigc.gpg_output)
+ strbuf_addstr(&sig, "gpg verification failed.\n");
+ else
+ strbuf_addstr(&sig, sigc.gpg_output);
+ signature_check_clear(&sigc);
if (!tag_number++) {
fmt_tag_signature(&tagbuf, &sig, buf, len);