Only look at tsig.error in responses

lib/dns/tsig.c

@@ -9,9 +9,6 @@
  * information regarding copyright ownership.
  */
 
-/*
- * $Id$
- */
 /*! \file */
 #include <config.h>
 
@@ -1427,8 +1424,9 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
 			goto cleanup_context;
 		}
 		msg->verified_sig = 1;
-	} else if (tsig.error != dns_tsigerror_badsig &&
-		   tsig.error != dns_tsigerror_badkey) {
+	} else if (!response || (tsig.error != dns_tsigerror_badsig &&
+				 tsig.error != dns_tsigerror_badkey))
+	{
 		tsig_log(msg->tsigkey, 2, "signature was empty");
 		return (DNS_R_TSIGVERIFYFAILURE);
 	}
@@ -1484,7 +1482,7 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
 		}
 	}
 
-	if (tsig.error != dns_rcode_noerror) {
+	if (response && tsig.error != dns_rcode_noerror) {
 		msg->tsigstatus = tsig.error;
 		if (tsig.error == dns_tsigerror_badtime)
 			ret = DNS_R_CLOCKSKEW;