1 /* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> 2 * SPDX-License-Identifier: GPL-3.0-or-later 3 */ 4 5 #pragma once 6 7 #include <libknot/packet/pkt.h> 8 9 /** High numbers in NSEC3 iterations don't really help security 10 * 11 * ...so we avoid doing all the work. The value is a current compromise; 12 * zones shooting over get downgraded to insecure status. 13 * 14 * Original restriction wasn't that strict: 15 https://datatracker.ietf.org/doc/html/rfc5155#section-10.3 16 * but there is discussion about officially lowering the limits: 17 https://tools.ietf.org/id/draft-hardaker-dnsop-nsec3-guidance-02.html#section-2.3 18 */ 19 #define KR_NSEC3_MAX_ITERATIONS 150 20 21 /** 22 * Name error response check (RFC5155 7.2.2). 23 * @note No RRSIGs are validated. 24 * @param pkt Packet structure to be processed. 25 * @param section_id Packet section to be processed. 26 * @param sname Name to be checked. 27 * @return 0 or error code. 28 */ 29 int kr_nsec3_name_error_response_check(const knot_pkt_t *pkt, knot_section_t section_id, 30 const knot_dname_t *sname); 31 32 /** 33 * Wildcard answer response check (RFC5155 7.2.6). 34 * @param pkt Packet structure to be processed. 35 * @param section_id Packet section to be processed. 36 * @param sname Name to be checked. 37 * @param trim_to_next Number of labels to remove to obtain next closer name. 38 * @return 0 or error code: 39 * KNOT_ERANGE - NSEC3 RR that covers a wildcard 40 * has been found, but has opt-out flag set; 41 * otherwise - error. 42 * Records over KR_NSEC3_MAX_ITERATIONS are skipped, so you probably get kr_error(ENOENT). 43 */ 44 int kr_nsec3_wildcard_answer_response_check(const knot_pkt_t *pkt, knot_section_t section_id, 45 const knot_dname_t *sname, int trim_to_next); 46 47 /** 48 * Authenticated denial of existence according to RFC5155 8.5 and 8.7. 49 * @note No RRSIGs are validated. 50 * @param pkt Packet structure to be processed. 51 * @param section_id Packet section to be processed. 52 * @param sname Queried domain name. 53 * @param stype Queried type. 54 * @return 0 or error code: 55 * DNSSEC_NOT_FOUND - neither ds nor nsec records 56 * were not found. 57 * KNOT_ERANGE - denial of existence can't be proven 58 * due to opt-out, otherwise - bogus. 59 */ 60 int kr_nsec3_no_data(const knot_pkt_t *pkt, knot_section_t section_id, 61 const knot_dname_t *sname, uint16_t stype); 62 63 /** 64 * Referral to unsigned subzone check (RFC5155 8.9). 65 * @note No RRSIGs are validated. 66 * @param pkt Packet structure to be processed. 67 * @return 0 or error code: 68 * KNOT_ERANGE - denial of existence can't be proven 69 * due to opt-out. 70 * EEXIST - ds record was found. 71 * EINVAL - bogus. 72 */ 73 int kr_nsec3_ref_to_unsigned(const knot_pkt_t *pkt); 74 75 /** 76 * Checks whether supplied NSEC3 RR matches the supplied name and NS type. 77 * @param nsec3 NSEC3 RR. 78 * @param name Name to be checked. 79 * @param type Type to be checked. Only use with NS! TODO 80 * @return 0 or error code. 81 */ 82 int kr_nsec3_matches_name_and_type(const knot_rrset_t *nsec3, 83 const knot_dname_t *name, uint16_t type); 84