- Fix negative cache NSEC3 parameter compares for zero length NSEC3

  salt.

doc/Changelog

@@ -1,3 +1,7 @@
+30 September 2024: Wouter
+	- Fix negative cache NSEC3 parameter compares for zero length NSEC3
+	  salt.
+
 25 September 2024: Wouter
 	- Fix #1144: [FR] log timestamps in ISO8601 format with timezone.
 	  This adds the option `log-time-iso: yes` that logs in ISO8601

validator/val_neg.c

@@ -823,7 +823,8 @@ void neg_insert_data(struct val_neg_cache* neg,
 			it <= neg->nsec3_max_iter &&
 			(h != zone->nsec3_hash || it != zone->nsec3_iter ||
 			slen != zone->nsec3_saltlen || 
-			memcmp(zone->nsec3_salt, s, slen) != 0)) {
+			(slen != 0 && zone->nsec3_salt && s
+			  && memcmp(zone->nsec3_salt, s, slen) != 0))) {
 
 			if(slen > 0) {
 				uint8_t* sa = memdup(s, slen);
@@ -1206,7 +1207,8 @@ neg_params_ok(struct val_neg_zone* zone, struct ub_packed_rrset_key* rrset)
 		return 0;
 	return (h == zone->nsec3_hash && it == zone->nsec3_iter &&
 		slen == zone->nsec3_saltlen &&
-		memcmp(zone->nsec3_salt, s, slen) == 0);
+		(slen != 0 && zone->nsec3_salt && s
+		  && memcmp(zone->nsec3_salt, s, slen) == 0));
 }
 
 /** get next closer for nsec3 proof */

validator/val_nsec3.c

@@ -565,7 +565,8 @@ nsec3_get_hashed(sldns_buffer* buf, uint8_t* nm, size_t nmlen, int algo,
 	sldns_buffer_clear(buf);
 	sldns_buffer_write(buf, nm, nmlen);
 	query_dname_tolower(sldns_buffer_begin(buf));
-	sldns_buffer_write(buf, salt, saltlen);
+	if(saltlen != 0)
+		sldns_buffer_write(buf, salt, saltlen);
 	sldns_buffer_flip(buf);
 	hash_len = nsec3_hash_algo_size_supported(algo);
 	if(hash_len == 0) {
@@ -580,7 +581,8 @@ nsec3_get_hashed(sldns_buffer* buf, uint8_t* nm, size_t nmlen, int algo,
 	for(i=0; i<iter; i++) {
 		sldns_buffer_clear(buf);
 		sldns_buffer_write(buf, res, hash_len);
-		sldns_buffer_write(buf, salt, saltlen);
+		if(saltlen != 0)
+			sldns_buffer_write(buf, salt, saltlen);
 		sldns_buffer_flip(buf);
 		if(!secalgo_nsec3_hash(algo,
 			(unsigned char*)sldns_buffer_begin(buf),