/*
* validator/val_nsec.h - validator NSEC denial of existence functions.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains helper functions for the validator module.
* The functions help with NSEC checking, the different NSEC proofs
* for denial of existence, and proofs for presence of types.
*/
#ifndef VALIDATOR_VAL_NSEC_H
#define VALIDATOR_VAL_NSEC_H
#include "util/data/packed_rrset.h"
struct val_env;
struct module_env;
struct ub_packed_rrset_key;
struct reply_info;
struct query_info;
struct key_entry_key;
/**
* Check DS absence.
* There is a NODATA reply to a DS that needs checking.
* NSECs can prove this is not a delegation point, or successfully prove
* that there is no DS. Or this fails.
*
* @param env: module env for rrsig verification routines.
* @param ve: validator env for rrsig verification routines.
* @param qinfo: the DS queried for.
* @param rep: reply received.
* @param kkey: key entry to use for verification of signatures.
* @param proof_ttl: if secure, the TTL of how long this proof lasts.
* @param reason: string explaining why bogus.
* @return security status.
* SECURE: proved absence of DS.
* INSECURE: proved that this was not a delegation point.
* BOGUS: crypto bad, or no absence of DS proven.
* UNCHECKED: there was no way to prove anything (no NSECs, unknown algo).
*/
enum sec_status val_nsec_prove_nodata_dsreply(struct module_env* env,
struct val_env* ve, struct query_info* qinfo,
struct reply_info* rep, struct key_entry_key* kkey,
time_t* proof_ttl, char** reason);
/**
* nsec typemap check, takes an NSEC-type bitmap as argument, checks for type.
* @param bitmap: pointer to the bitmap part of wireformat rdata.
* @param len: length of the bitmap, in bytes.
* @param type: the type (in host order) to check for.
* @return true if the type bit was set in the bitmap. false if not, or
* if the bitmap was malformed in some way.
*/
int nsecbitmap_has_type_rdata(uint8_t* bitmap, size_t len, uint16_t type);
/**
* Check if type is present in the NSEC typemap
* @param nsec: the nsec RRset.
* If there are multiple RRs, then each must have the same typemap,
* since the typemap represents the types at this domain node.
* @param type: type to check for, host order.
* @return true if present
*/
int nsec_has_type(struct ub_packed_rrset_key* nsec, uint16_t type);
/**
* Determine if a NSEC proves the NOERROR/NODATA conditions. This will also
* handle the empty non-terminal (ENT) case and partially handle the
* wildcard case. If the ownername of 'nsec' is a wildcard, the validator
* must still be provided proof that qname did not directly exist and that
* the wildcard is, in fact, *.closest_encloser.
*
* @param nsec: the nsec record to check against.
* @param qinfo: the query info.
* @param wc: if the nodata is proven for a wildcard match, the wildcard
* closest encloser is returned, else NULL (wc is unchanged).
* This closest encloser must then match the nameerror given for the
* nextcloser of qname.
* @return true if NSEC proves this.
*/
int nsec_proves_nodata(struct ub_packed_rrset_key* nsec,
struct query_info* qinfo, uint8_t** wc);
/**
* Determine if the given NSEC proves a NameError (NXDOMAIN) for a given
* qname.
*
* @param nsec: the nsec to check
* @param qname: what was queried.
* @return true if proven.
*/
int val_nsec_proves_name_error(struct ub_packed_rrset_key* nsec,
uint8_t* qname);
/**
* Determine if the given NSEC proves a positive wildcard response.
* @param nsec: the nsec to check
* @param qinf: what was queried.
* @param wc: wildcard (without *. label)
* @return true if proven.
*/
int val_nsec_proves_positive_wildcard(struct ub_packed_rrset_key* nsec,
struct query_info* qinf, uint8_t* wc);
/**
* Determine closest encloser of a query name and the NSEC that covers it
* (and thus disproved it).
* A name error must have been proven already, otherwise this will be invalid.
* @param qname: the name queried for.
* @param nsec: the nsec RRset.
* @return closest encloser dname or NULL on error (bad nsec RRset).
*/
uint8_t* nsec_closest_encloser(uint8_t* qname,
struct ub_packed_rrset_key* nsec);
/**
* Determine if the given NSEC proves that a wildcard match does not exist.
*
* @param nsec: the nsec RRset.
* @param qname: the name queried for.
* @param qnamelen: length of qname.
* @return true if proven.
*/
int val_nsec_proves_no_wc(struct ub_packed_rrset_key* nsec, uint8_t* qname,
size_t qnamelen);
/**
* Determine the DLV result, what to do with NSEC DLV reply.
* @param qinfo: what was queried for.
* @param rep: the nonpositive reply.
* @param nm: dlv lookup name, to adjust for new lookup name (if needed).
* @param nm_len: length of lookup name.
* @return 0 on error, 1 if a higher point is found.
* If the higher point is above the dlv repo anchor, the qname does
* not exist.
*/
int val_nsec_check_dlv(struct query_info* qinfo,
struct reply_info* rep, uint8_t** nm, size_t* nm_len);
/**
* Determine if an nsec proves an insecure delegation towards the qname.
* @param nsec: nsec rrset.
* @param qinfo: what was queries for.
* @return 0 if not, 1 if an NSEC that signals an insecure delegation to
* the qname.
*/
int val_nsec_proves_insecuredelegation(struct ub_packed_rrset_key* nsec,
struct query_info* qinfo);
#endif /* VALIDATOR_VAL_NSEC_H */
