verify-tag: factor out signature detection

into tag.h/c for later reuse and modification.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/tag.c b/tag.c
index 28641cf85..d4f3080e3 100644
--- a/tag.c
+++ b/tag.c
@@ -4,6 +4,8 @@
 #include "tree.h"
 #include "blob.h"
 
+#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
+
 const char *tag_type = "tag";
 
 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
@@ -133,3 +135,14 @@ int parse_tag(struct tag *item)
 	free(data);
 	return ret;
 }
+
+size_t parse_signature(const char *buf, unsigned long size)
+{
+	char *eol;
+	size_t len = 0;
+	while (len < size && prefixcmp(buf + len, PGP_SIGNATURE)) {
+		eol = memchr(buf + len, '\n', size - len);
+		len += eol ? eol - (buf + len) + 1 : size - len;
+	}
+	return len;
+}