7911e492f9
wildcard synthesized NSEC records. git-svn-id: https://unbound.nlnetlabs.nl/svn/trunk@4441 be551aaa-1e26-0410-a405-d3ace91eadb9
1436 lines
45 KiB
C
1436 lines
45 KiB
C
/*
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* validator/val_nsec3.c - validator NSEC3 denial of existence functions.
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*
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* Copyright (c) 2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file contains helper functions for the validator module.
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* The functions help with NSEC3 checking, the different NSEC3 proofs
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* for denial of existence, and proofs for presence of types.
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*/
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#include "config.h"
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#include <ctype.h>
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#include "validator/val_nsec3.h"
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#include "validator/val_secalgo.h"
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#include "validator/validator.h"
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#include "validator/val_kentry.h"
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#include "services/cache/rrset.h"
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#include "util/regional.h"
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#include "util/rbtree.h"
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#include "util/module.h"
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#include "util/net_help.h"
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#include "util/data/packed_rrset.h"
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#include "util/data/dname.h"
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#include "util/data/msgreply.h"
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/* we include nsec.h for the bitmap_has_type function */
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#include "validator/val_nsec.h"
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#include "sldns/sbuffer.h"
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/**
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* This function we get from ldns-compat or from base system
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* it returns the number of data bytes stored at the target, or <0 on error.
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*/
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int sldns_b32_ntop_extended_hex(uint8_t const *src, size_t srclength,
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char *target, size_t targsize);
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/**
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* This function we get from ldns-compat or from base system
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* it returns the number of data bytes stored at the target, or <0 on error.
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*/
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int sldns_b32_pton_extended_hex(char const *src, size_t hashed_owner_str_len,
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uint8_t *target, size_t targsize);
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/**
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* Closest encloser (ce) proof results
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* Contains the ce and the next-closer (nc) proof.
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*/
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struct ce_response {
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/** the closest encloser name */
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uint8_t* ce;
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/** length of ce */
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size_t ce_len;
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/** NSEC3 record that proved ce. rrset */
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struct ub_packed_rrset_key* ce_rrset;
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/** NSEC3 record that proved ce. rr number */
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int ce_rr;
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/** NSEC3 record that proved nc. rrset */
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struct ub_packed_rrset_key* nc_rrset;
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/** NSEC3 record that proved nc. rr*/
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int nc_rr;
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};
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/**
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* Filter conditions for NSEC3 proof
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* Used to iterate over the applicable NSEC3 RRs.
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*/
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struct nsec3_filter {
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/** Zone name, only NSEC3 records for this zone are considered */
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uint8_t* zone;
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/** length of the zonename */
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size_t zone_len;
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/** the list of NSEC3s to filter; array */
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struct ub_packed_rrset_key** list;
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/** number of rrsets in list */
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size_t num;
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/** class of records for the NSEC3, only this class applies */
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uint16_t fclass;
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};
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/** return number of rrs in an rrset */
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static size_t
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rrset_get_count(struct ub_packed_rrset_key* rrset)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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if(!d) return 0;
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return d->count;
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}
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/** return if nsec3 RR has unknown flags */
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static int
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nsec3_unknown_flags(struct ub_packed_rrset_key* rrset, int r)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+2)
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return 0; /* malformed */
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return (int)(d->rr_data[r][2+1] & NSEC3_UNKNOWN_FLAGS);
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}
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int
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nsec3_has_optout(struct ub_packed_rrset_key* rrset, int r)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+2)
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return 0; /* malformed */
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return (int)(d->rr_data[r][2+1] & NSEC3_OPTOUT);
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}
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/** return nsec3 RR algorithm */
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static int
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nsec3_get_algo(struct ub_packed_rrset_key* rrset, int r)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+1)
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return 0; /* malformed */
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return (int)(d->rr_data[r][2+0]);
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}
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/** return if nsec3 RR has known algorithm */
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static int
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nsec3_known_algo(struct ub_packed_rrset_key* rrset, int r)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+1)
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return 0; /* malformed */
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switch(d->rr_data[r][2+0]) {
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case NSEC3_HASH_SHA1:
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return 1;
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}
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return 0;
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}
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/** return nsec3 RR iteration count */
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static size_t
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nsec3_get_iter(struct ub_packed_rrset_key* rrset, int r)
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{
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uint16_t i;
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+4)
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return 0; /* malformed */
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memmove(&i, d->rr_data[r]+2+2, sizeof(i));
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i = ntohs(i);
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return (size_t)i;
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}
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/** return nsec3 RR salt */
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static int
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nsec3_get_salt(struct ub_packed_rrset_key* rrset, int r,
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uint8_t** salt, size_t* saltlen)
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{
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+5) {
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*salt = 0;
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*saltlen = 0;
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return 0; /* malformed */
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}
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*saltlen = (size_t)d->rr_data[r][2+4];
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if(d->rr_len[r] < 2+5+(size_t)*saltlen) {
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*salt = 0;
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*saltlen = 0;
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return 0; /* malformed */
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}
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*salt = d->rr_data[r]+2+5;
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return 1;
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}
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int nsec3_get_params(struct ub_packed_rrset_key* rrset, int r,
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int* algo, size_t* iter, uint8_t** salt, size_t* saltlen)
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{
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if(!nsec3_known_algo(rrset, r) || nsec3_unknown_flags(rrset, r))
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return 0;
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if(!nsec3_get_salt(rrset, r, salt, saltlen))
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return 0;
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*algo = nsec3_get_algo(rrset, r);
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*iter = nsec3_get_iter(rrset, r);
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return 1;
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}
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int
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nsec3_get_nextowner(struct ub_packed_rrset_key* rrset, int r,
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uint8_t** next, size_t* nextlen)
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{
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size_t saltlen;
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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if(d->rr_len[r] < 2+5) {
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*next = 0;
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*nextlen = 0;
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return 0; /* malformed */
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}
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saltlen = (size_t)d->rr_data[r][2+4];
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if(d->rr_len[r] < 2+5+saltlen+1) {
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*next = 0;
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*nextlen = 0;
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return 0; /* malformed */
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}
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*nextlen = (size_t)d->rr_data[r][2+5+saltlen];
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if(d->rr_len[r] < 2+5+saltlen+1+*nextlen) {
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*next = 0;
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*nextlen = 0;
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return 0; /* malformed */
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}
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*next = d->rr_data[r]+2+5+saltlen+1;
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return 1;
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}
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size_t nsec3_hash_to_b32(uint8_t* hash, size_t hashlen, uint8_t* zone,
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size_t zonelen, uint8_t* buf, size_t max)
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{
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/* write b32 of name, leave one for length */
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int ret;
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if(max < hashlen*2+1) /* quick approx of b32, as if hexb16 */
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return 0;
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ret = sldns_b32_ntop_extended_hex(hash, hashlen, (char*)buf+1, max-1);
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if(ret < 1)
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return 0;
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buf[0] = (uint8_t)ret; /* length of b32 label */
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ret++;
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if(max - ret < zonelen)
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return 0;
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memmove(buf+ret, zone, zonelen);
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return zonelen+(size_t)ret;
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}
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size_t nsec3_get_nextowner_b32(struct ub_packed_rrset_key* rrset, int r,
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uint8_t* buf, size_t max)
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{
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uint8_t* nm, *zone;
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size_t nmlen, zonelen;
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if(!nsec3_get_nextowner(rrset, r, &nm, &nmlen))
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return 0;
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/* append zone name; the owner name must be <b32>.zone */
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zone = rrset->rk.dname;
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zonelen = rrset->rk.dname_len;
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dname_remove_label(&zone, &zonelen);
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return nsec3_hash_to_b32(nm, nmlen, zone, zonelen, buf, max);
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}
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int
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nsec3_has_type(struct ub_packed_rrset_key* rrset, int r, uint16_t type)
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{
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uint8_t* bitmap;
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size_t bitlen, skiplen;
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struct packed_rrset_data* d = (struct packed_rrset_data*)
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rrset->entry.data;
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log_assert(d && r < (int)d->count);
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skiplen = 2+4;
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/* skip salt */
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if(d->rr_len[r] < skiplen+1)
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return 0; /* malformed, too short */
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skiplen += 1+(size_t)d->rr_data[r][skiplen];
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/* skip next hashed owner */
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if(d->rr_len[r] < skiplen+1)
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return 0; /* malformed, too short */
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skiplen += 1+(size_t)d->rr_data[r][skiplen];
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if(d->rr_len[r] < skiplen)
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return 0; /* malformed, too short */
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bitlen = d->rr_len[r] - skiplen;
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bitmap = d->rr_data[r]+skiplen;
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return nsecbitmap_has_type_rdata(bitmap, bitlen, type);
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}
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/**
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* Iterate through NSEC3 list, per RR
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* This routine gives the next RR in the list (or sets rrset null).
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* Usage:
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*
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* size_t rrsetnum;
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* int rrnum;
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* struct ub_packed_rrset_key* rrset;
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* for(rrset=filter_first(filter, &rrsetnum, &rrnum); rrset;
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* rrset=filter_next(filter, &rrsetnum, &rrnum))
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* do_stuff;
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*
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* Also filters out
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* o unknown flag NSEC3s
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* o unknown algorithm NSEC3s.
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* @param filter: nsec3 filter structure.
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* @param rrsetnum: in/out rrset number to look at.
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* @param rrnum: in/out rr number in rrset to look at.
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* @returns ptr to the next rrset (or NULL at end).
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*/
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static struct ub_packed_rrset_key*
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filter_next(struct nsec3_filter* filter, size_t* rrsetnum, int* rrnum)
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{
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size_t i;
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int r;
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uint8_t* nm;
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size_t nmlen;
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if(!filter->zone) /* empty list */
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return NULL;
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for(i=*rrsetnum; i<filter->num; i++) {
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/* see if RRset qualifies */
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if(ntohs(filter->list[i]->rk.type) != LDNS_RR_TYPE_NSEC3 ||
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ntohs(filter->list[i]->rk.rrset_class) !=
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filter->fclass)
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continue;
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/* check RRset zone */
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nm = filter->list[i]->rk.dname;
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nmlen = filter->list[i]->rk.dname_len;
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dname_remove_label(&nm, &nmlen);
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if(query_dname_compare(nm, filter->zone) != 0)
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continue;
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if(i == *rrsetnum)
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r = (*rrnum) + 1; /* continue at next RR */
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else r = 0; /* new RRset start at first RR */
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for(; r < (int)rrset_get_count(filter->list[i]); r++) {
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/* skip unknown flags, algo */
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if(nsec3_unknown_flags(filter->list[i], r) ||
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!nsec3_known_algo(filter->list[i], r))
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continue;
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/* this one is a good target */
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*rrsetnum = i;
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*rrnum = r;
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return filter->list[i];
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}
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}
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return NULL;
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}
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/**
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* Start iterating over NSEC3 records.
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* @param filter: the filter structure, must have been filter_init-ed.
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* @param rrsetnum: can be undefined on call, initialised.
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* @param rrnum: can be undefined on call, initialised.
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* @return first rrset of an NSEC3, together with rrnum this points to
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* the first RR to examine. Is NULL on empty list.
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*/
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static struct ub_packed_rrset_key*
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filter_first(struct nsec3_filter* filter, size_t* rrsetnum, int* rrnum)
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{
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*rrsetnum = 0;
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*rrnum = -1;
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return filter_next(filter, rrsetnum, rrnum);
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}
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/** see if at least one RR is known (flags, algo) */
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static int
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nsec3_rrset_has_known(struct ub_packed_rrset_key* s)
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{
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int r;
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for(r=0; r < (int)rrset_get_count(s); r++) {
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if(!nsec3_unknown_flags(s, r) && nsec3_known_algo(s, r))
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return 1;
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}
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return 0;
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}
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/**
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* Initialize the filter structure.
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* Finds the zone by looking at available NSEC3 records and best match.
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* (skips the unknown flag and unknown algo NSEC3s).
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*
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* @param filter: nsec3 filter structure.
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* @param list: list of rrsets, an array of them.
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* @param num: number of rrsets in list.
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* @param qinfo:
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* query name to match a zone for.
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* query type (if DS a higher zone must be chosen)
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* qclass, to filter NSEC3s with.
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*/
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static void
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filter_init(struct nsec3_filter* filter, struct ub_packed_rrset_key** list,
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size_t num, struct query_info* qinfo)
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{
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size_t i;
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uint8_t* nm;
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size_t nmlen;
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filter->zone = NULL;
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filter->zone_len = 0;
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filter->list = list;
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filter->num = num;
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filter->fclass = qinfo->qclass;
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for(i=0; i<num; i++) {
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/* ignore other stuff in the list */
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if(ntohs(list[i]->rk.type) != LDNS_RR_TYPE_NSEC3 ||
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ntohs(list[i]->rk.rrset_class) != qinfo->qclass)
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continue;
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/* skip unknown flags, algo */
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if(!nsec3_rrset_has_known(list[i]))
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continue;
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/* since NSEC3s are base32.zonename, we can find the zone
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* name by stripping off the first label of the record */
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nm = list[i]->rk.dname;
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nmlen = list[i]->rk.dname_len;
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dname_remove_label(&nm, &nmlen);
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/* if we find a domain that can prove about the qname,
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* and if this domain is closer to the qname */
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if(dname_subdomain_c(qinfo->qname, nm) && (!filter->zone ||
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dname_subdomain_c(nm, filter->zone))) {
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/* for a type DS do not accept a zone equal to qname*/
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if(qinfo->qtype == LDNS_RR_TYPE_DS &&
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query_dname_compare(qinfo->qname, nm) == 0 &&
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!dname_is_root(qinfo->qname))
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continue;
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filter->zone = nm;
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filter->zone_len = nmlen;
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}
|
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}
|
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}
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|
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/**
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* Find max iteration count using config settings and key size
|
|
* @param ve: validator environment with iteration count config settings.
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* @param bits: key size
|
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* @return max iteration count
|
|
*/
|
|
static size_t
|
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get_max_iter(struct val_env* ve, size_t bits)
|
|
{
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int i;
|
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log_assert(ve->nsec3_keyiter_count > 0);
|
|
/* round up to nearest config keysize, linear search, keep it small */
|
|
for(i=0; i<ve->nsec3_keyiter_count; i++) {
|
|
if(bits <= ve->nsec3_keysize[i])
|
|
return ve->nsec3_maxiter[i];
|
|
}
|
|
/* else, use value for biggest key */
|
|
return ve->nsec3_maxiter[ve->nsec3_keyiter_count-1];
|
|
}
|
|
|
|
/**
|
|
* Determine if any of the NSEC3 rrs iteration count is too high, from key.
|
|
* @param ve: validator environment with iteration count config settings.
|
|
* @param filter: what NSEC3s to loop over.
|
|
* @param kkey: key entry used for verification; used for iteration counts.
|
|
* @return 1 if some nsec3s are above the max iteration count.
|
|
*/
|
|
static int
|
|
nsec3_iteration_count_high(struct val_env* ve, struct nsec3_filter* filter,
|
|
struct key_entry_key* kkey)
|
|
{
|
|
size_t rrsetnum;
|
|
int rrnum;
|
|
struct ub_packed_rrset_key* rrset;
|
|
/* first determine the max number of iterations */
|
|
size_t bits = key_entry_keysize(kkey);
|
|
size_t max_iter = get_max_iter(ve, bits);
|
|
verbose(VERB_ALGO, "nsec3: keysize %d bits, max iterations %d",
|
|
(int)bits, (int)max_iter);
|
|
|
|
for(rrset=filter_first(filter, &rrsetnum, &rrnum); rrset;
|
|
rrset=filter_next(filter, &rrsetnum, &rrnum)) {
|
|
if(nsec3_get_iter(rrset, rrnum) > max_iter)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* nsec3_cache_compare for rbtree */
|
|
int
|
|
nsec3_hash_cmp(const void* c1, const void* c2)
|
|
{
|
|
struct nsec3_cached_hash* h1 = (struct nsec3_cached_hash*)c1;
|
|
struct nsec3_cached_hash* h2 = (struct nsec3_cached_hash*)c2;
|
|
uint8_t* s1, *s2;
|
|
size_t s1len, s2len;
|
|
int c = query_dname_compare(h1->dname, h2->dname);
|
|
if(c != 0)
|
|
return c;
|
|
/* compare parameters */
|
|
/* if both malformed, its equal, robustness */
|
|
if(nsec3_get_algo(h1->nsec3, h1->rr) !=
|
|
nsec3_get_algo(h2->nsec3, h2->rr)) {
|
|
if(nsec3_get_algo(h1->nsec3, h1->rr) <
|
|
nsec3_get_algo(h2->nsec3, h2->rr))
|
|
return -1;
|
|
return 1;
|
|
}
|
|
if(nsec3_get_iter(h1->nsec3, h1->rr) !=
|
|
nsec3_get_iter(h2->nsec3, h2->rr)) {
|
|
if(nsec3_get_iter(h1->nsec3, h1->rr) <
|
|
nsec3_get_iter(h2->nsec3, h2->rr))
|
|
return -1;
|
|
return 1;
|
|
}
|
|
(void)nsec3_get_salt(h1->nsec3, h1->rr, &s1, &s1len);
|
|
(void)nsec3_get_salt(h2->nsec3, h2->rr, &s2, &s2len);
|
|
if(s1len != s2len) {
|
|
if(s1len < s2len)
|
|
return -1;
|
|
return 1;
|
|
}
|
|
return memcmp(s1, s2, s1len);
|
|
}
|
|
|
|
size_t
|
|
nsec3_get_hashed(sldns_buffer* buf, uint8_t* nm, size_t nmlen, int algo,
|
|
size_t iter, uint8_t* salt, size_t saltlen, uint8_t* res, size_t max)
|
|
{
|
|
size_t i, hash_len;
|
|
/* prepare buffer for first iteration */
|
|
sldns_buffer_clear(buf);
|
|
sldns_buffer_write(buf, nm, nmlen);
|
|
query_dname_tolower(sldns_buffer_begin(buf));
|
|
sldns_buffer_write(buf, salt, saltlen);
|
|
sldns_buffer_flip(buf);
|
|
hash_len = nsec3_hash_algo_size_supported(algo);
|
|
if(hash_len == 0) {
|
|
log_err("nsec3 hash of unknown algo %d", algo);
|
|
return 0;
|
|
}
|
|
if(hash_len > max)
|
|
return 0;
|
|
if(!secalgo_nsec3_hash(algo, (unsigned char*)sldns_buffer_begin(buf),
|
|
sldns_buffer_limit(buf), (unsigned char*)res))
|
|
return 0;
|
|
for(i=0; i<iter; i++) {
|
|
sldns_buffer_clear(buf);
|
|
sldns_buffer_write(buf, res, hash_len);
|
|
sldns_buffer_write(buf, salt, saltlen);
|
|
sldns_buffer_flip(buf);
|
|
if(!secalgo_nsec3_hash(algo,
|
|
(unsigned char*)sldns_buffer_begin(buf),
|
|
sldns_buffer_limit(buf), (unsigned char*)res))
|
|
return 0;
|
|
}
|
|
return hash_len;
|
|
}
|
|
|
|
/** perform hash of name */
|
|
static int
|
|
nsec3_calc_hash(struct regional* region, sldns_buffer* buf,
|
|
struct nsec3_cached_hash* c)
|
|
{
|
|
int algo = nsec3_get_algo(c->nsec3, c->rr);
|
|
size_t iter = nsec3_get_iter(c->nsec3, c->rr);
|
|
uint8_t* salt;
|
|
size_t saltlen, i;
|
|
if(!nsec3_get_salt(c->nsec3, c->rr, &salt, &saltlen))
|
|
return -1;
|
|
/* prepare buffer for first iteration */
|
|
sldns_buffer_clear(buf);
|
|
sldns_buffer_write(buf, c->dname, c->dname_len);
|
|
query_dname_tolower(sldns_buffer_begin(buf));
|
|
sldns_buffer_write(buf, salt, saltlen);
|
|
sldns_buffer_flip(buf);
|
|
c->hash_len = nsec3_hash_algo_size_supported(algo);
|
|
if(c->hash_len == 0) {
|
|
log_err("nsec3 hash of unknown algo %d", algo);
|
|
return -1;
|
|
}
|
|
c->hash = (uint8_t*)regional_alloc(region, c->hash_len);
|
|
if(!c->hash)
|
|
return 0;
|
|
(void)secalgo_nsec3_hash(algo, (unsigned char*)sldns_buffer_begin(buf),
|
|
sldns_buffer_limit(buf), (unsigned char*)c->hash);
|
|
for(i=0; i<iter; i++) {
|
|
sldns_buffer_clear(buf);
|
|
sldns_buffer_write(buf, c->hash, c->hash_len);
|
|
sldns_buffer_write(buf, salt, saltlen);
|
|
sldns_buffer_flip(buf);
|
|
(void)secalgo_nsec3_hash(algo,
|
|
(unsigned char*)sldns_buffer_begin(buf),
|
|
sldns_buffer_limit(buf), (unsigned char*)c->hash);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/** perform b32 encoding of hash */
|
|
static int
|
|
nsec3_calc_b32(struct regional* region, sldns_buffer* buf,
|
|
struct nsec3_cached_hash* c)
|
|
{
|
|
int r;
|
|
sldns_buffer_clear(buf);
|
|
r = sldns_b32_ntop_extended_hex(c->hash, c->hash_len,
|
|
(char*)sldns_buffer_begin(buf), sldns_buffer_limit(buf));
|
|
if(r < 1) {
|
|
log_err("b32_ntop_extended_hex: error in encoding: %d", r);
|
|
return 0;
|
|
}
|
|
c->b32_len = (size_t)r;
|
|
c->b32 = regional_alloc_init(region, sldns_buffer_begin(buf),
|
|
c->b32_len);
|
|
if(!c->b32)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
nsec3_hash_name(rbtree_type* table, struct regional* region, sldns_buffer* buf,
|
|
struct ub_packed_rrset_key* nsec3, int rr, uint8_t* dname,
|
|
size_t dname_len, struct nsec3_cached_hash** hash)
|
|
{
|
|
struct nsec3_cached_hash* c;
|
|
struct nsec3_cached_hash looki;
|
|
#ifdef UNBOUND_DEBUG
|
|
rbnode_type* n;
|
|
#endif
|
|
int r;
|
|
looki.node.key = &looki;
|
|
looki.nsec3 = nsec3;
|
|
looki.rr = rr;
|
|
looki.dname = dname;
|
|
looki.dname_len = dname_len;
|
|
/* lookup first in cache */
|
|
c = (struct nsec3_cached_hash*)rbtree_search(table, &looki);
|
|
if(c) {
|
|
*hash = c;
|
|
return 1;
|
|
}
|
|
/* create a new entry */
|
|
c = (struct nsec3_cached_hash*)regional_alloc(region, sizeof(*c));
|
|
if(!c) return 0;
|
|
c->node.key = c;
|
|
c->nsec3 = nsec3;
|
|
c->rr = rr;
|
|
c->dname = dname;
|
|
c->dname_len = dname_len;
|
|
r = nsec3_calc_hash(region, buf, c);
|
|
if(r != 1)
|
|
return r;
|
|
r = nsec3_calc_b32(region, buf, c);
|
|
if(r != 1)
|
|
return r;
|
|
#ifdef UNBOUND_DEBUG
|
|
n =
|
|
#else
|
|
(void)
|
|
#endif
|
|
rbtree_insert(table, &c->node);
|
|
log_assert(n); /* cannot be duplicate, just did lookup */
|
|
*hash = c;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* compare a label lowercased
|
|
*/
|
|
static int
|
|
label_compare_lower(uint8_t* lab1, uint8_t* lab2, size_t lablen)
|
|
{
|
|
size_t i;
|
|
for(i=0; i<lablen; i++) {
|
|
if(tolower((unsigned char)*lab1) != tolower((unsigned char)*lab2)) {
|
|
if(tolower((unsigned char)*lab1) < tolower((unsigned char)*lab2))
|
|
return -1;
|
|
return 1;
|
|
}
|
|
lab1++;
|
|
lab2++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Compare a hashed name with the owner name of an NSEC3 RRset.
|
|
* @param flt: filter with zone name.
|
|
* @param hash: the hashed name.
|
|
* @param s: rrset with owner name.
|
|
* @return true if matches exactly, false if not.
|
|
*/
|
|
static int
|
|
nsec3_hash_matches_owner(struct nsec3_filter* flt,
|
|
struct nsec3_cached_hash* hash, struct ub_packed_rrset_key* s)
|
|
{
|
|
uint8_t* nm = s->rk.dname;
|
|
/* compare, does hash of name based on params in this NSEC3
|
|
* match the owner name of this NSEC3?
|
|
* name must be: <hashlength>base32 . zone name
|
|
* so; first label must not be root label (not zero length),
|
|
* and match the b32 encoded hash length,
|
|
* and the label content match the b32 encoded hash
|
|
* and the rest must be the zone name.
|
|
*/
|
|
if(hash->b32_len != 0 && (size_t)nm[0] == hash->b32_len &&
|
|
label_compare_lower(nm+1, hash->b32, hash->b32_len) == 0 &&
|
|
query_dname_compare(nm+(size_t)nm[0]+1, flt->zone) == 0) {
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Find matching NSEC3
|
|
* Find the NSEC3Record that matches a hash of a name.
|
|
* @param env: module environment with temporary region and buffer.
|
|
* @param flt: the NSEC3 RR filter, contains zone name and RRs.
|
|
* @param ct: cached hashes table.
|
|
* @param nm: name to look for.
|
|
* @param nmlen: length of name.
|
|
* @param rrset: nsec3 that matches is returned here.
|
|
* @param rr: rr number in nsec3 rrset that matches.
|
|
* @return true if a matching NSEC3 is found, false if not.
|
|
*/
|
|
static int
|
|
find_matching_nsec3(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, uint8_t* nm, size_t nmlen,
|
|
struct ub_packed_rrset_key** rrset, int* rr)
|
|
{
|
|
size_t i_rs;
|
|
int i_rr;
|
|
struct ub_packed_rrset_key* s;
|
|
struct nsec3_cached_hash* hash;
|
|
int r;
|
|
|
|
/* this loop skips other-zone and unknown NSEC3s, also non-NSEC3 RRs */
|
|
for(s=filter_first(flt, &i_rs, &i_rr); s;
|
|
s=filter_next(flt, &i_rs, &i_rr)) {
|
|
/* get name hashed for this NSEC3 RR */
|
|
r = nsec3_hash_name(ct, env->scratch, env->scratch_buffer,
|
|
s, i_rr, nm, nmlen, &hash);
|
|
if(r == 0) {
|
|
log_err("nsec3: malloc failure");
|
|
break; /* alloc failure */
|
|
} else if(r < 0)
|
|
continue; /* malformed NSEC3 */
|
|
else if(nsec3_hash_matches_owner(flt, hash, s)) {
|
|
*rrset = s; /* rrset with this name */
|
|
*rr = i_rr; /* matches hash with these parameters */
|
|
return 1;
|
|
}
|
|
}
|
|
*rrset = NULL;
|
|
*rr = 0;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
nsec3_covers(uint8_t* zone, struct nsec3_cached_hash* hash,
|
|
struct ub_packed_rrset_key* rrset, int rr, sldns_buffer* buf)
|
|
{
|
|
uint8_t* next, *owner;
|
|
size_t nextlen;
|
|
int len;
|
|
if(!nsec3_get_nextowner(rrset, rr, &next, &nextlen))
|
|
return 0; /* malformed RR proves nothing */
|
|
|
|
/* check the owner name is a hashed value . apex
|
|
* base32 encoded values must have equal length.
|
|
* hash_value and next hash value must have equal length. */
|
|
if(nextlen != hash->hash_len || hash->hash_len==0||hash->b32_len==0||
|
|
(size_t)*rrset->rk.dname != hash->b32_len ||
|
|
query_dname_compare(rrset->rk.dname+1+
|
|
(size_t)*rrset->rk.dname, zone) != 0)
|
|
return 0; /* bad lengths or owner name */
|
|
|
|
/* This is the "normal case: owner < next and owner < hash < next */
|
|
if(label_compare_lower(rrset->rk.dname+1, hash->b32,
|
|
hash->b32_len) < 0 &&
|
|
memcmp(hash->hash, next, nextlen) < 0)
|
|
return 1;
|
|
|
|
/* convert owner name from text to binary */
|
|
sldns_buffer_clear(buf);
|
|
owner = sldns_buffer_begin(buf);
|
|
len = sldns_b32_pton_extended_hex((char*)rrset->rk.dname+1,
|
|
hash->b32_len, owner, sldns_buffer_limit(buf));
|
|
if(len<1)
|
|
return 0; /* bad owner name in some way */
|
|
if((size_t)len != hash->hash_len || (size_t)len != nextlen)
|
|
return 0; /* wrong length */
|
|
|
|
/* this is the end of zone case: next <= owner &&
|
|
* (hash > owner || hash < next)
|
|
* this also covers the only-apex case of next==owner.
|
|
*/
|
|
if(memcmp(next, owner, nextlen) <= 0 &&
|
|
( memcmp(hash->hash, owner, nextlen) > 0 ||
|
|
memcmp(hash->hash, next, nextlen) < 0)) {
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* findCoveringNSEC3
|
|
* Given a name, find a covering NSEC3 from among a list of NSEC3s.
|
|
*
|
|
* @param env: module environment with temporary region and buffer.
|
|
* @param flt: the NSEC3 RR filter, contains zone name and RRs.
|
|
* @param ct: cached hashes table.
|
|
* @param nm: name to check if covered.
|
|
* @param nmlen: length of name.
|
|
* @param rrset: covering NSEC3 rrset is returned here.
|
|
* @param rr: rr of cover is returned here.
|
|
* @return true if a covering NSEC3 is found, false if not.
|
|
*/
|
|
static int
|
|
find_covering_nsec3(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, uint8_t* nm, size_t nmlen,
|
|
struct ub_packed_rrset_key** rrset, int* rr)
|
|
{
|
|
size_t i_rs;
|
|
int i_rr;
|
|
struct ub_packed_rrset_key* s;
|
|
struct nsec3_cached_hash* hash;
|
|
int r;
|
|
|
|
/* this loop skips other-zone and unknown NSEC3s, also non-NSEC3 RRs */
|
|
for(s=filter_first(flt, &i_rs, &i_rr); s;
|
|
s=filter_next(flt, &i_rs, &i_rr)) {
|
|
/* get name hashed for this NSEC3 RR */
|
|
r = nsec3_hash_name(ct, env->scratch, env->scratch_buffer,
|
|
s, i_rr, nm, nmlen, &hash);
|
|
if(r == 0) {
|
|
log_err("nsec3: malloc failure");
|
|
break; /* alloc failure */
|
|
} else if(r < 0)
|
|
continue; /* malformed NSEC3 */
|
|
else if(nsec3_covers(flt->zone, hash, s, i_rr,
|
|
env->scratch_buffer)) {
|
|
*rrset = s; /* rrset with this name */
|
|
*rr = i_rr; /* covers hash with these parameters */
|
|
return 1;
|
|
}
|
|
}
|
|
*rrset = NULL;
|
|
*rr = 0;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* findClosestEncloser
|
|
* Given a name and a list of NSEC3s, find the candidate closest encloser.
|
|
* This will be the first ancestor of 'name' (including itself) to have a
|
|
* matching NSEC3 RR.
|
|
* @param env: module environment with temporary region and buffer.
|
|
* @param flt: the NSEC3 RR filter, contains zone name and RRs.
|
|
* @param ct: cached hashes table.
|
|
* @param qinfo: query that is verified for.
|
|
* @param ce: closest encloser information is returned in here.
|
|
* @return true if a closest encloser candidate is found, false if not.
|
|
*/
|
|
static int
|
|
nsec3_find_closest_encloser(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, struct query_info* qinfo, struct ce_response* ce)
|
|
{
|
|
uint8_t* nm = qinfo->qname;
|
|
size_t nmlen = qinfo->qname_len;
|
|
|
|
/* This scans from longest name to shortest, so the first match
|
|
* we find is the only viable candidate. */
|
|
|
|
/* (David:) FIXME: modify so that the NSEC3 matching the zone apex need
|
|
* not be present. (Mark Andrews idea).
|
|
* (Wouter:) But make sure you check for DNAME bit in zone apex,
|
|
* if the NSEC3 you find is the only NSEC3 in the zone, then this
|
|
* may be the case. */
|
|
|
|
while(dname_subdomain_c(nm, flt->zone)) {
|
|
if(find_matching_nsec3(env, flt, ct, nm, nmlen,
|
|
&ce->ce_rrset, &ce->ce_rr)) {
|
|
ce->ce = nm;
|
|
ce->ce_len = nmlen;
|
|
return 1;
|
|
}
|
|
dname_remove_label(&nm, &nmlen);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Given a qname and its proven closest encloser, calculate the "next
|
|
* closest" name. Basically, this is the name that is one label longer than
|
|
* the closest encloser that is still a subdomain of qname.
|
|
*
|
|
* @param qname: query name.
|
|
* @param qnamelen: length of qname.
|
|
* @param ce: closest encloser
|
|
* @param nm: result name.
|
|
* @param nmlen: length of nm.
|
|
*/
|
|
static void
|
|
next_closer(uint8_t* qname, size_t qnamelen, uint8_t* ce,
|
|
uint8_t** nm, size_t* nmlen)
|
|
{
|
|
int strip = dname_count_labels(qname) - dname_count_labels(ce) -1;
|
|
*nm = qname;
|
|
*nmlen = qnamelen;
|
|
if(strip>0)
|
|
dname_remove_labels(nm, nmlen, strip);
|
|
}
|
|
|
|
/**
|
|
* proveClosestEncloser
|
|
* Given a List of nsec3 RRs, find and prove the closest encloser to qname.
|
|
* @param env: module environment with temporary region and buffer.
|
|
* @param flt: the NSEC3 RR filter, contains zone name and RRs.
|
|
* @param ct: cached hashes table.
|
|
* @param qinfo: query that is verified for.
|
|
* @param prove_does_not_exist: If true, then if the closest encloser
|
|
* turns out to be qname, then null is returned.
|
|
* If set true, and the return value is true, then you can be
|
|
* certain that the ce.nc_rrset and ce.nc_rr are set properly.
|
|
* @param ce: closest encloser information is returned in here.
|
|
* @return bogus if no closest encloser could be proven.
|
|
* secure if a closest encloser could be proven, ce is set.
|
|
* insecure if the closest-encloser candidate turns out to prove
|
|
* that an insecure delegation exists above the qname.
|
|
*/
|
|
static enum sec_status
|
|
nsec3_prove_closest_encloser(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, struct query_info* qinfo, int prove_does_not_exist,
|
|
struct ce_response* ce)
|
|
{
|
|
uint8_t* nc;
|
|
size_t nc_len;
|
|
/* robust: clean out ce, in case it gets abused later */
|
|
memset(ce, 0, sizeof(*ce));
|
|
|
|
if(!nsec3_find_closest_encloser(env, flt, ct, qinfo, ce)) {
|
|
verbose(VERB_ALGO, "nsec3 proveClosestEncloser: could "
|
|
"not find a candidate for the closest encloser.");
|
|
return sec_status_bogus;
|
|
}
|
|
log_nametypeclass(VERB_ALGO, "ce candidate", ce->ce, 0, 0);
|
|
|
|
if(query_dname_compare(ce->ce, qinfo->qname) == 0) {
|
|
if(prove_does_not_exist) {
|
|
verbose(VERB_ALGO, "nsec3 proveClosestEncloser: "
|
|
"proved that qname existed, bad");
|
|
return sec_status_bogus;
|
|
}
|
|
/* otherwise, we need to nothing else to prove that qname
|
|
* is its own closest encloser. */
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/* If the closest encloser is actually a delegation, then the
|
|
* response should have been a referral. If it is a DNAME, then
|
|
* it should have been a DNAME response. */
|
|
if(nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_NS) &&
|
|
!nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_SOA)) {
|
|
if(!nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_DS)) {
|
|
verbose(VERB_ALGO, "nsec3 proveClosestEncloser: "
|
|
"closest encloser is insecure delegation");
|
|
return sec_status_insecure;
|
|
}
|
|
verbose(VERB_ALGO, "nsec3 proveClosestEncloser: closest "
|
|
"encloser was a delegation, bad");
|
|
return sec_status_bogus;
|
|
}
|
|
if(nsec3_has_type(ce->ce_rrset, ce->ce_rr, LDNS_RR_TYPE_DNAME)) {
|
|
verbose(VERB_ALGO, "nsec3 proveClosestEncloser: closest "
|
|
"encloser was a DNAME, bad");
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
/* Otherwise, we need to show that the next closer name is covered. */
|
|
next_closer(qinfo->qname, qinfo->qname_len, ce->ce, &nc, &nc_len);
|
|
if(!find_covering_nsec3(env, flt, ct, nc, nc_len,
|
|
&ce->nc_rrset, &ce->nc_rr)) {
|
|
verbose(VERB_ALGO, "nsec3: Could not find proof that the "
|
|
"candidate encloser was the closest encloser");
|
|
return sec_status_bogus;
|
|
}
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/** allocate a wildcard for the closest encloser */
|
|
static uint8_t*
|
|
nsec3_ce_wildcard(struct regional* region, uint8_t* ce, size_t celen,
|
|
size_t* len)
|
|
{
|
|
uint8_t* nm;
|
|
if(celen > LDNS_MAX_DOMAINLEN - 2)
|
|
return 0; /* too long */
|
|
nm = (uint8_t*)regional_alloc(region, celen+2);
|
|
if(!nm) {
|
|
log_err("nsec3 wildcard: out of memory");
|
|
return 0; /* alloc failure */
|
|
}
|
|
nm[0] = 1;
|
|
nm[1] = (uint8_t)'*'; /* wildcard label */
|
|
memmove(nm+2, ce, celen);
|
|
*len = celen+2;
|
|
return nm;
|
|
}
|
|
|
|
/** Do the name error proof */
|
|
static enum sec_status
|
|
nsec3_do_prove_nameerror(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, struct query_info* qinfo)
|
|
{
|
|
struct ce_response ce;
|
|
uint8_t* wc;
|
|
size_t wclen;
|
|
struct ub_packed_rrset_key* wc_rrset;
|
|
int wc_rr;
|
|
enum sec_status sec;
|
|
|
|
/* First locate and prove the closest encloser to qname. We will
|
|
* use the variant that fails if the closest encloser turns out
|
|
* to be qname. */
|
|
sec = nsec3_prove_closest_encloser(env, flt, ct, qinfo, 1, &ce);
|
|
if(sec != sec_status_secure) {
|
|
if(sec == sec_status_bogus)
|
|
verbose(VERB_ALGO, "nsec3 nameerror proof: failed "
|
|
"to prove a closest encloser");
|
|
else verbose(VERB_ALGO, "nsec3 nameerror proof: closest "
|
|
"nsec3 is an insecure delegation");
|
|
return sec;
|
|
}
|
|
log_nametypeclass(VERB_ALGO, "nsec3 nameerror: proven ce=", ce.ce,0,0);
|
|
|
|
/* At this point, we know that qname does not exist. Now we need
|
|
* to prove that the wildcard does not exist. */
|
|
log_assert(ce.ce);
|
|
wc = nsec3_ce_wildcard(env->scratch, ce.ce, ce.ce_len, &wclen);
|
|
if(!wc || !find_covering_nsec3(env, flt, ct, wc, wclen,
|
|
&wc_rrset, &wc_rr)) {
|
|
verbose(VERB_ALGO, "nsec3 nameerror proof: could not prove "
|
|
"that the applicable wildcard did not exist.");
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
|
|
verbose(VERB_ALGO, "nsec3 nameerror proof: nc has optout");
|
|
return sec_status_insecure;
|
|
}
|
|
return sec_status_secure;
|
|
}
|
|
|
|
enum sec_status
|
|
nsec3_prove_nameerror(struct module_env* env, struct val_env* ve,
|
|
struct ub_packed_rrset_key** list, size_t num,
|
|
struct query_info* qinfo, struct key_entry_key* kkey)
|
|
{
|
|
rbtree_type ct;
|
|
struct nsec3_filter flt;
|
|
|
|
if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
|
|
return sec_status_bogus; /* no valid NSEC3s, bogus */
|
|
rbtree_init(&ct, &nsec3_hash_cmp); /* init names-to-hash cache */
|
|
filter_init(&flt, list, num, qinfo); /* init RR iterator */
|
|
if(!flt.zone)
|
|
return sec_status_bogus; /* no RRs */
|
|
if(nsec3_iteration_count_high(ve, &flt, kkey))
|
|
return sec_status_insecure; /* iteration count too high */
|
|
log_nametypeclass(VERB_ALGO, "start nsec3 nameerror proof, zone",
|
|
flt.zone, 0, 0);
|
|
return nsec3_do_prove_nameerror(env, &flt, &ct, qinfo);
|
|
}
|
|
|
|
/*
|
|
* No code to handle qtype=NSEC3 specially.
|
|
* This existed in early drafts, but was later (-05) removed.
|
|
*/
|
|
|
|
/** Do the nodata proof */
|
|
static enum sec_status
|
|
nsec3_do_prove_nodata(struct module_env* env, struct nsec3_filter* flt,
|
|
rbtree_type* ct, struct query_info* qinfo)
|
|
{
|
|
struct ce_response ce;
|
|
uint8_t* wc;
|
|
size_t wclen;
|
|
struct ub_packed_rrset_key* rrset;
|
|
int rr;
|
|
enum sec_status sec;
|
|
|
|
if(find_matching_nsec3(env, flt, ct, qinfo->qname, qinfo->qname_len,
|
|
&rrset, &rr)) {
|
|
/* cases 1 and 2 */
|
|
if(nsec3_has_type(rrset, rr, qinfo->qtype)) {
|
|
verbose(VERB_ALGO, "proveNodata: Matching NSEC3 "
|
|
"proved that type existed, bogus");
|
|
return sec_status_bogus;
|
|
} else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_CNAME)) {
|
|
verbose(VERB_ALGO, "proveNodata: Matching NSEC3 "
|
|
"proved that a CNAME existed, bogus");
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
/*
|
|
* If type DS: filter_init zone find already found a parent
|
|
* zone, so this nsec3 is from a parent zone.
|
|
* o can be not a delegation (unusual query for normal name,
|
|
* no DS anyway, but we can verify that).
|
|
* o can be a delegation (which is the usual DS check).
|
|
* o may not have the SOA bit set (only the top of the
|
|
* zone, which must have been above the name, has that).
|
|
* Except for the root; which is checked by itself.
|
|
*
|
|
* If not type DS: matching nsec3 must not be a delegation.
|
|
*/
|
|
if(qinfo->qtype == LDNS_RR_TYPE_DS && qinfo->qname_len != 1
|
|
&& nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA) &&
|
|
!dname_is_root(qinfo->qname)) {
|
|
verbose(VERB_ALGO, "proveNodata: apex NSEC3 "
|
|
"abused for no DS proof, bogus");
|
|
return sec_status_bogus;
|
|
} else if(qinfo->qtype != LDNS_RR_TYPE_DS &&
|
|
nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS) &&
|
|
!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
|
|
if(!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_DS)) {
|
|
verbose(VERB_ALGO, "proveNodata: matching "
|
|
"NSEC3 is insecure delegation");
|
|
return sec_status_insecure;
|
|
}
|
|
verbose(VERB_ALGO, "proveNodata: matching "
|
|
"NSEC3 is a delegation, bogus");
|
|
return sec_status_bogus;
|
|
}
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/* For cases 3 - 5, we need the proven closest encloser, and it
|
|
* can't match qname. Although, at this point, we know that it
|
|
* won't since we just checked that. */
|
|
sec = nsec3_prove_closest_encloser(env, flt, ct, qinfo, 1, &ce);
|
|
if(sec == sec_status_bogus) {
|
|
verbose(VERB_ALGO, "proveNodata: did not match qname, "
|
|
"nor found a proven closest encloser.");
|
|
return sec_status_bogus;
|
|
} else if(sec==sec_status_insecure && qinfo->qtype!=LDNS_RR_TYPE_DS){
|
|
verbose(VERB_ALGO, "proveNodata: closest nsec3 is insecure "
|
|
"delegation.");
|
|
return sec_status_insecure;
|
|
}
|
|
|
|
/* Case 3: removed */
|
|
|
|
/* Case 4: */
|
|
log_assert(ce.ce);
|
|
wc = nsec3_ce_wildcard(env->scratch, ce.ce, ce.ce_len, &wclen);
|
|
if(wc && find_matching_nsec3(env, flt, ct, wc, wclen, &rrset, &rr)) {
|
|
/* found wildcard */
|
|
if(nsec3_has_type(rrset, rr, qinfo->qtype)) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: matching "
|
|
"wildcard had qtype, bogus");
|
|
return sec_status_bogus;
|
|
} else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_CNAME)) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: matching "
|
|
"wildcard had a CNAME, bogus");
|
|
return sec_status_bogus;
|
|
}
|
|
if(qinfo->qtype == LDNS_RR_TYPE_DS && qinfo->qname_len != 1
|
|
&& nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: matching "
|
|
"wildcard for no DS proof has a SOA, bogus");
|
|
return sec_status_bogus;
|
|
} else if(qinfo->qtype != LDNS_RR_TYPE_DS &&
|
|
nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS) &&
|
|
!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA)) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: matching "
|
|
"wildcard is a delegation, bogus");
|
|
return sec_status_bogus;
|
|
}
|
|
/* everything is peachy keen, except for optout spans */
|
|
if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: matching "
|
|
"wildcard is in optout range, insecure");
|
|
return sec_status_insecure;
|
|
}
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/* Case 5: */
|
|
/* Due to forwarders, cnames, and other collating effects, we
|
|
* can see the ordinary unsigned data from a zone beneath an
|
|
* insecure delegation under an optout here */
|
|
if(!ce.nc_rrset) {
|
|
verbose(VERB_ALGO, "nsec3 nodata proof: no next closer nsec3");
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
/* We need to make sure that the covering NSEC3 is opt-out. */
|
|
log_assert(ce.nc_rrset);
|
|
if(!nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
|
|
if(qinfo->qtype == LDNS_RR_TYPE_DS)
|
|
verbose(VERB_ALGO, "proveNodata: covering NSEC3 was not "
|
|
"opt-out in an opt-out DS NOERROR/NODATA case.");
|
|
else verbose(VERB_ALGO, "proveNodata: could not find matching "
|
|
"NSEC3, nor matching wildcard, nor optout NSEC3 "
|
|
"-- no more options, bogus.");
|
|
return sec_status_bogus;
|
|
}
|
|
/* RFC5155 section 9.2: if nc has optout then no AD flag set */
|
|
return sec_status_insecure;
|
|
}
|
|
|
|
enum sec_status
|
|
nsec3_prove_nodata(struct module_env* env, struct val_env* ve,
|
|
struct ub_packed_rrset_key** list, size_t num,
|
|
struct query_info* qinfo, struct key_entry_key* kkey)
|
|
{
|
|
rbtree_type ct;
|
|
struct nsec3_filter flt;
|
|
|
|
if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
|
|
return sec_status_bogus; /* no valid NSEC3s, bogus */
|
|
rbtree_init(&ct, &nsec3_hash_cmp); /* init names-to-hash cache */
|
|
filter_init(&flt, list, num, qinfo); /* init RR iterator */
|
|
if(!flt.zone)
|
|
return sec_status_bogus; /* no RRs */
|
|
if(nsec3_iteration_count_high(ve, &flt, kkey))
|
|
return sec_status_insecure; /* iteration count too high */
|
|
return nsec3_do_prove_nodata(env, &flt, &ct, qinfo);
|
|
}
|
|
|
|
enum sec_status
|
|
nsec3_prove_wildcard(struct module_env* env, struct val_env* ve,
|
|
struct ub_packed_rrset_key** list, size_t num,
|
|
struct query_info* qinfo, struct key_entry_key* kkey, uint8_t* wc)
|
|
{
|
|
rbtree_type ct;
|
|
struct nsec3_filter flt;
|
|
struct ce_response ce;
|
|
uint8_t* nc;
|
|
size_t nc_len;
|
|
size_t wclen;
|
|
(void)dname_count_size_labels(wc, &wclen);
|
|
|
|
if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
|
|
return sec_status_bogus; /* no valid NSEC3s, bogus */
|
|
rbtree_init(&ct, &nsec3_hash_cmp); /* init names-to-hash cache */
|
|
filter_init(&flt, list, num, qinfo); /* init RR iterator */
|
|
if(!flt.zone)
|
|
return sec_status_bogus; /* no RRs */
|
|
if(nsec3_iteration_count_high(ve, &flt, kkey))
|
|
return sec_status_insecure; /* iteration count too high */
|
|
|
|
/* We know what the (purported) closest encloser is by just
|
|
* looking at the supposed generating wildcard.
|
|
* The *. has already been removed from the wc name.
|
|
*/
|
|
memset(&ce, 0, sizeof(ce));
|
|
ce.ce = wc;
|
|
ce.ce_len = wclen;
|
|
|
|
/* Now we still need to prove that the original data did not exist.
|
|
* Otherwise, we need to show that the next closer name is covered. */
|
|
next_closer(qinfo->qname, qinfo->qname_len, ce.ce, &nc, &nc_len);
|
|
if(!find_covering_nsec3(env, &flt, &ct, nc, nc_len,
|
|
&ce.nc_rrset, &ce.nc_rr)) {
|
|
verbose(VERB_ALGO, "proveWildcard: did not find a covering "
|
|
"NSEC3 that covered the next closer name.");
|
|
return sec_status_bogus;
|
|
}
|
|
if(ce.nc_rrset && nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
|
|
verbose(VERB_ALGO, "proveWildcard: NSEC3 optout");
|
|
return sec_status_insecure;
|
|
}
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/** test if list is all secure */
|
|
static int
|
|
list_is_secure(struct module_env* env, struct val_env* ve,
|
|
struct ub_packed_rrset_key** list, size_t num,
|
|
struct key_entry_key* kkey, char** reason, struct module_qstate* qstate)
|
|
{
|
|
struct packed_rrset_data* d;
|
|
size_t i;
|
|
for(i=0; i<num; i++) {
|
|
d = (struct packed_rrset_data*)list[i]->entry.data;
|
|
if(list[i]->rk.type != htons(LDNS_RR_TYPE_NSEC3))
|
|
continue;
|
|
if(d->security == sec_status_secure)
|
|
continue;
|
|
rrset_check_sec_status(env->rrset_cache, list[i], *env->now);
|
|
if(d->security == sec_status_secure)
|
|
continue;
|
|
d->security = val_verify_rrset_entry(env, ve, list[i], kkey,
|
|
reason, LDNS_SECTION_AUTHORITY, qstate);
|
|
if(d->security != sec_status_secure) {
|
|
verbose(VERB_ALGO, "NSEC3 did not verify");
|
|
return 0;
|
|
}
|
|
rrset_update_sec_status(env->rrset_cache, list[i], *env->now);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
enum sec_status
|
|
nsec3_prove_nods(struct module_env* env, struct val_env* ve,
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struct ub_packed_rrset_key** list, size_t num,
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struct query_info* qinfo, struct key_entry_key* kkey, char** reason,
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struct module_qstate* qstate)
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|
{
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rbtree_type ct;
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struct nsec3_filter flt;
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struct ce_response ce;
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struct ub_packed_rrset_key* rrset;
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int rr;
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log_assert(qinfo->qtype == LDNS_RR_TYPE_DS);
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|
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if(!list || num == 0 || !kkey || !key_entry_isgood(kkey)) {
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*reason = "no valid NSEC3s";
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return sec_status_bogus; /* no valid NSEC3s, bogus */
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}
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if(!list_is_secure(env, ve, list, num, kkey, reason, qstate))
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return sec_status_bogus; /* not all NSEC3 records secure */
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rbtree_init(&ct, &nsec3_hash_cmp); /* init names-to-hash cache */
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filter_init(&flt, list, num, qinfo); /* init RR iterator */
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if(!flt.zone) {
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*reason = "no NSEC3 records";
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return sec_status_bogus; /* no RRs */
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}
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if(nsec3_iteration_count_high(ve, &flt, kkey))
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return sec_status_insecure; /* iteration count too high */
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|
|
|
/* Look for a matching NSEC3 to qname -- this is the normal
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* NODATA case. */
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if(find_matching_nsec3(env, &flt, &ct, qinfo->qname, qinfo->qname_len,
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&rrset, &rr)) {
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/* If the matching NSEC3 has the SOA bit set, it is from
|
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* the wrong zone (the child instead of the parent). If
|
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* it has the DS bit set, then we were lied to. */
|
|
if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_SOA) &&
|
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qinfo->qname_len != 1) {
|
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verbose(VERB_ALGO, "nsec3 provenods: NSEC3 is from"
|
|
" child zone, bogus");
|
|
*reason = "NSEC3 from child zone";
|
|
return sec_status_bogus;
|
|
} else if(nsec3_has_type(rrset, rr, LDNS_RR_TYPE_DS)) {
|
|
verbose(VERB_ALGO, "nsec3 provenods: NSEC3 has qtype"
|
|
" DS, bogus");
|
|
*reason = "NSEC3 has DS in bitmap";
|
|
return sec_status_bogus;
|
|
}
|
|
/* If the NSEC3 RR doesn't have the NS bit set, then
|
|
* this wasn't a delegation point. */
|
|
if(!nsec3_has_type(rrset, rr, LDNS_RR_TYPE_NS))
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|
return sec_status_indeterminate;
|
|
/* Otherwise, this proves no DS. */
|
|
return sec_status_secure;
|
|
}
|
|
|
|
/* Otherwise, we are probably in the opt-out case. */
|
|
if(nsec3_prove_closest_encloser(env, &flt, &ct, qinfo, 1, &ce)
|
|
!= sec_status_secure) {
|
|
/* an insecure delegation *above* the qname does not prove
|
|
* anything about this qname exactly, and bogus is bogus */
|
|
verbose(VERB_ALGO, "nsec3 provenods: did not match qname, "
|
|
"nor found a proven closest encloser.");
|
|
*reason = "no NSEC3 closest encloser";
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
/* robust extra check */
|
|
if(!ce.nc_rrset) {
|
|
verbose(VERB_ALGO, "nsec3 nods proof: no next closer nsec3");
|
|
*reason = "no NSEC3 next closer";
|
|
return sec_status_bogus;
|
|
}
|
|
|
|
/* we had the closest encloser proof, then we need to check that the
|
|
* covering NSEC3 was opt-out -- the proveClosestEncloser step already
|
|
* checked to see if the closest encloser was a delegation or DNAME.
|
|
*/
|
|
log_assert(ce.nc_rrset);
|
|
if(!nsec3_has_optout(ce.nc_rrset, ce.nc_rr)) {
|
|
verbose(VERB_ALGO, "nsec3 provenods: covering NSEC3 was not "
|
|
"opt-out in an opt-out DS NOERROR/NODATA case.");
|
|
*reason = "covering NSEC3 was not opt-out in an opt-out "
|
|
"DS NOERROR/NODATA case";
|
|
return sec_status_bogus;
|
|
}
|
|
/* RFC5155 section 9.2: if nc has optout then no AD flag set */
|
|
return sec_status_insecure;
|
|
}
|
|
|
|
enum sec_status
|
|
nsec3_prove_nxornodata(struct module_env* env, struct val_env* ve,
|
|
struct ub_packed_rrset_key** list, size_t num,
|
|
struct query_info* qinfo, struct key_entry_key* kkey, int* nodata)
|
|
{
|
|
enum sec_status sec, secnx;
|
|
rbtree_type ct;
|
|
struct nsec3_filter flt;
|
|
*nodata = 0;
|
|
|
|
if(!list || num == 0 || !kkey || !key_entry_isgood(kkey))
|
|
return sec_status_bogus; /* no valid NSEC3s, bogus */
|
|
rbtree_init(&ct, &nsec3_hash_cmp); /* init names-to-hash cache */
|
|
filter_init(&flt, list, num, qinfo); /* init RR iterator */
|
|
if(!flt.zone)
|
|
return sec_status_bogus; /* no RRs */
|
|
if(nsec3_iteration_count_high(ve, &flt, kkey))
|
|
return sec_status_insecure; /* iteration count too high */
|
|
|
|
/* try nxdomain and nodata after another, while keeping the
|
|
* hash cache intact */
|
|
|
|
secnx = nsec3_do_prove_nameerror(env, &flt, &ct, qinfo);
|
|
if(secnx==sec_status_secure)
|
|
return sec_status_secure;
|
|
sec = nsec3_do_prove_nodata(env, &flt, &ct, qinfo);
|
|
if(sec==sec_status_secure) {
|
|
*nodata = 1;
|
|
} else if(sec == sec_status_insecure) {
|
|
*nodata = 1;
|
|
} else if(secnx == sec_status_insecure) {
|
|
sec = sec_status_insecure;
|
|
}
|
|
return sec;
|
|
}
|