commit 759a6c7b4d25900b15c4a118937f1669c967691e
from: Martijn van Duren <martijn@openbsd.org>
date: Thu Mar 24 12:59:51 2022 UTC

return early if there are missing tags in DKIM-Signature

commit - 8015d1bca797db805913f3c7bf404de4a249bc3b
commit + 759a6c7b4d25900b15c4a118937f1669c967691e
blob - 2c9c58e9eeb74963eee77589703a751132203164
blob + e3054ed42860f51f2f3643c04692b1546dc4f3a2
--- main.c
+++ main.c
@@ -475,6 +475,8 @@ dkim_signature_parse(struct header *header)
 		dkim_signature_state(sig, DKIM_PERMERROR, "Missing h tag");
 	else if (sig->s[0] == '\0')
 		dkim_signature_state(sig, DKIM_PERMERROR, "Missing s tag");
+	if (sig->state != DKIM_UNKNOWN)
+		return;
 
 	if ((size_t)snprintf(subdomain, sizeof(subdomain), "%s._domainkey.%s",
 	    sig->s, sig->d) >= sizeof(subdomain)) {