Re: [PATCH 3/6] ssh signing: verify-commit/check_signature with commit date

+	if (payload_timestamp) {
+		strbuf_addf(&verify_time, "-Overify-time=%s",
+			    show_date(payload_timestamp, 0, &verify_date_mode));
+	}

@@ -482,6 +495,7 @@ static int verify_ssh_signed_buffer(struct signature_check *sigc,
 		error(_("ssh-keygen -Y find-principals/verify is needed for ssh signature verification (available in openssh version 8.2p1+)"));
 		goto out;
 	}
+
 	if (ret || !ssh_principals_out.len) {
 		/*
 		 * We did not find a matching principal in the allowedSigners

+int parse_signed_buffer_metadata(const char *payload, const char *signer_header,
+				 timestamp_t *payload_timestamp,
+				 struct strbuf *payload_signer)
+{
+	const char *ident_line = NULL;
+	size_t ident_len;
+	struct ident_split ident;
+
+	ident_line = find_commit_header(payload, signer_header, &ident_len);
+	if (ident_line && ident_len) {
+		if (!split_ident_line(&ident, ident_line, ident_len)) {
+			if (payload_timestamp && ident.date_begin &&
+			    ident.date_end)
+				*payload_timestamp = parse_timestamp(
+					ident.date_begin, NULL, 10);
+			if (payload_signer)
+				strbuf_add(payload_signer, ident.mail_begin,
+					(ident.mail_end - ident.mail_begin));
+
+			return 0;
+		}
+	}
+
+	return 1;
+}