IABSD.fr/src/sbin/unwind/libunbound/validator/val_utils.c

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• Author : sthen
  Date : 2026-05-27 20:40:22
  Hash : a9dc7358
  Message : merge changes from unbound 1.25.1, ok florian

• sbin/unwind/libunbound/validator/val_utils.c

• /*
   * validator/val_utils.c - validator utility 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.
   */
  #include "config.h"
  #include "validator/val_utils.h"
  #include "validator/validator.h"
  #include "validator/val_kentry.h"
  #include "validator/val_sigcrypt.h"
  #include "validator/val_anchor.h"
  #include "validator/val_nsec.h"
  #include "validator/val_neg.h"
  #include "services/cache/rrset.h"
  #include "services/cache/dns.h"
  #include "util/data/msgreply.h"
  #include "util/data/packed_rrset.h"
  #include "util/data/dname.h"
  #include "util/net_help.h"
  #include "util/module.h"
  #include "util/regional.h"
  #include "util/config_file.h"
  #include "sldns/wire2str.h"
  #include "sldns/parseutil.h"
  
  /** Maximum allowed digest match failures per DS, for DNSKEYs with the same
   *  properties */
  #define MAX_DS_MATCH_FAILURES 4
  
  enum val_classification 
  val_classify_response(uint16_t query_flags, struct query_info* origqinf,
  	struct query_info* qinf, struct reply_info* rep, size_t skip)
  {
  	int rcode = (int)FLAGS_GET_RCODE(rep->flags);
  	size_t i;
  
  	/* Normal Name Error's are easy to detect -- but don't mistake a CNAME
  	 * chain ending in NXDOMAIN. */
  	if(rcode == LDNS_RCODE_NXDOMAIN && rep->an_numrrsets == 0)
  		return VAL_CLASS_NAMEERROR;
  
  	/* check for referral: nonRD query and it looks like a nodata */
  	if(!(query_flags&BIT_RD) && rep->an_numrrsets == 0 &&
  		rcode == LDNS_RCODE_NOERROR) {
  		/* SOA record in auth indicates it is NODATA instead.
  		 * All validation requiring NODATA messages have SOA in 
  		 * authority section. */
  		/* uses fact that answer section is empty */
  		int saw_ns = 0;
  		for(i=0; i<rep->ns_numrrsets; i++) {
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_SOA)
  				return VAL_CLASS_NODATA;
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_DS)
  				return VAL_CLASS_REFERRAL;
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
  				saw_ns = 1;
  		}
  		return saw_ns?VAL_CLASS_REFERRAL:VAL_CLASS_NODATA;
  	}
  	/* root referral where NS set is in the answer section */
  	if(!(query_flags&BIT_RD) && rep->ns_numrrsets == 0 &&
  		rep->an_numrrsets == 1 && rcode == LDNS_RCODE_NOERROR &&
  		ntohs(rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_NS &&
  		query_dname_compare(rep->rrsets[0]->rk.dname, 
  			origqinf->qname) != 0)
  		return VAL_CLASS_REFERRAL;
  
  	/* dump bad messages */
  	if(rcode != LDNS_RCODE_NOERROR && rcode != LDNS_RCODE_NXDOMAIN)
  		return VAL_CLASS_UNKNOWN;
  	/* next check if the skip into the answer section shows no answer */
  	if(skip>0 && rep->an_numrrsets <= skip)
  		return VAL_CLASS_CNAMENOANSWER;
  
  	/* Next is NODATA */
  	if(rcode == LDNS_RCODE_NOERROR && rep->an_numrrsets == 0)
  		return VAL_CLASS_NODATA;
  	
  	/* We distinguish between CNAME response and other positive/negative
  	 * responses because CNAME answers require extra processing. */
  
  	/* We distinguish between ANY and CNAME or POSITIVE because 
  	 * ANY responses are validated differently. */
  	if(rcode == LDNS_RCODE_NOERROR && qinf->qtype == LDNS_RR_TYPE_ANY)
  		return VAL_CLASS_ANY;
  
  	/* For the query type DNAME, the name matters. Equal name is the
  	 * answer looked for, but a subdomain redirects the query. */
  	if(qinf->qtype == LDNS_RR_TYPE_DNAME) {
  		for(i=skip; i<rep->an_numrrsets; i++) {
  			if(rcode == LDNS_RCODE_NOERROR &&
  				ntohs(rep->rrsets[i]->rk.type)
  				== LDNS_RR_TYPE_DNAME &&
  				query_dname_compare(qinf->qname,
  				rep->rrsets[i]->rk.dname) == 0) {
  				/* type is DNAME and name is equal, it is
  				 * the answer. For the query name a subdomain
  				 * of the rrset.dname it would redirect. */
  				return VAL_CLASS_POSITIVE;
  			}
  			if(ntohs(rep->rrsets[i]->rk.type)
  				== LDNS_RR_TYPE_CNAME)
  				return VAL_CLASS_CNAME;
  		}
  		log_dns_msg("validator: error. failed to classify response message: ",
  			qinf, rep);
  		return VAL_CLASS_UNKNOWN;
  	}
  
  	/* Note that DNAMEs will be ignored here, unless qtype=DNAME. Unless
  	 * qtype=CNAME, this will yield a CNAME response. */
  	for(i=skip; i<rep->an_numrrsets; i++) {
  		if(rcode == LDNS_RCODE_NOERROR &&
  			ntohs(rep->rrsets[i]->rk.type) == qinf->qtype)
  			return VAL_CLASS_POSITIVE;
  		if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME)
  			return VAL_CLASS_CNAME;
  	}
  	log_dns_msg("validator: error. failed to classify response message: ",
  		qinf, rep);
  	return VAL_CLASS_UNKNOWN;
  }
  
  /** Get signer name from RRSIG */
  static void
  rrsig_get_signer(uint8_t* data, size_t len, uint8_t** sname, size_t* slen)
  {
  	/* RRSIG rdata is not allowed to be compressed, it is stored
  	 * uncompressed in memory as well, so return a ptr to the name */
  	if(len < 21) {
  		/* too short RRSig:
  		 * short, byte, byte, long, long, long, short, "." is
  		 * 2	1	1	4	4  4	2	1 = 19
  		 * 			and a skip of 18 bytes to the name.
  		 * +2 for the rdatalen is 21 bytes len for root label */
  		*sname = NULL;
  		*slen = 0;
  		return;
  	}
  	data += 20; /* skip the fixed size bits */
  	len -= 20;
  	*slen = dname_valid(data, len);
  	if(!*slen) {
  		/* bad dname in this rrsig. */
  		*sname = NULL;
  		return;
  	}
  	*sname = data;
  }
  
  void 
  val_find_rrset_signer(struct ub_packed_rrset_key* rrset, uint8_t** sname,
  	size_t* slen)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)
  		rrset->entry.data;
  	/* return signer for first signature, or NULL */
  	if(d->rrsig_count == 0) {
  		*sname = NULL;
  		*slen = 0;
  		return;
  	}
  	/* get rrsig signer name out of the signature */
  	rrsig_get_signer(d->rr_data[d->count], d->rr_len[d->count], 
  		sname, slen);
  }
  
  /**
   * Find best signer name in this set of rrsigs.
   * @param rrset: which rrsigs to look through.
   * @param qinf: the query name that needs validation.
   * @param signer_name: the best signer_name. Updated if a better one is found.
   * @param signer_len: length of signer name.
   * @param matchcount: count of current best name (starts at 0 for no match).
   * 	Updated if match is improved.
   */
  static void
  val_find_best_signer(struct ub_packed_rrset_key* rrset, 
  	struct query_info* qinf, uint8_t** signer_name, size_t* signer_len, 
  	int* matchcount)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)
  		rrset->entry.data;
  	uint8_t* sign;
  	size_t i;
  	int m;
  	for(i=d->count; i<d->count+d->rrsig_count; i++) {
  		sign = d->rr_data[i]+2+18;
  		/* look at signatures that are valid (long enough),
  		 * and have a signer name that is a superdomain of qname,
  		 * and then check the number of labels in the shared topdomain
  		 * improve the match if possible */
  		if(d->rr_len[i] > 2+19 && /* rdata, sig + root label*/
  			dname_subdomain_c(qinf->qname, sign)) {
  			(void)dname_lab_cmp(qinf->qname, 
  				dname_count_labels(qinf->qname), 
  				sign, dname_count_labels(sign), &m);
  			if(m > *matchcount) {
  				*matchcount = m;
  				*signer_name = sign;
  				(void)dname_count_size_labels(*signer_name,
  					signer_len);
  			}
  		}
  	}
  }
  
  /** Detect if the, unsigned, CNAME is under a previous DNAME RR in the
   * message, and thus it was generated from that previous DNAME.
   */
  static int
  cname_under_previous_dname(struct reply_info* rep, size_t cname_idx,
  	size_t* ret)
  {
  	size_t i;
  	for(i=0; i<cname_idx; i++) {
  		if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_DNAME &&
  			dname_strict_subdomain_c(rep->rrsets[cname_idx]->
  			rk.dname, rep->rrsets[i]->rk.dname)) {
  			*ret = i;
  			return 1;
  		}
  	}
  	*ret = 0;
  	return 0;
  }
  
  void 
  val_find_signer(enum val_classification subtype, struct query_info* qinf, 
  	struct reply_info* rep, size_t skip, uint8_t** signer_name, 
  	size_t* signer_len)
  {
  	size_t i;
  	
  	if(subtype == VAL_CLASS_POSITIVE) {
  		/* check for the answer rrset */
  		for(i=skip; i<rep->an_numrrsets; i++) {
  			if(query_dname_compare(qinf->qname, 
  				rep->rrsets[i]->rk.dname) == 0) {
  				val_find_rrset_signer(rep->rrsets[i], 
  					signer_name, signer_len);
  				/* If there was no signer, and the query
  				 * was for type CNAME, and this is a CNAME,
  				 * and the previous is a DNAME, then this
  				 * is the synthesized CNAME, use the signer
  				 * of the DNAME record. */
  				if(*signer_name == NULL &&
  				   qinf->qtype == LDNS_RR_TYPE_CNAME &&
  				   ntohs(rep->rrsets[i]->rk.type) ==
  				   LDNS_RR_TYPE_CNAME && i > skip &&
  				   ntohs(rep->rrsets[i-1]->rk.type) ==
  				   LDNS_RR_TYPE_DNAME &&
  				   dname_strict_subdomain_c(rep->rrsets[i]->rk.dname, rep->rrsets[i-1]->rk.dname)) {
  					val_find_rrset_signer(rep->rrsets[i-1],
  						signer_name, signer_len);
  				}
  				return;
  			}
  		}
  		*signer_name = NULL;
  		*signer_len = 0;
  	} else if(subtype == VAL_CLASS_CNAME) {
  		size_t j;
  		/* check for the first signed cname/dname rrset */
  		for(i=skip; i<rep->an_numrrsets; i++) {
  			val_find_rrset_signer(rep->rrsets[i], 
  				signer_name, signer_len);
  			if(*signer_name)
  				return;
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME
  				&& cname_under_previous_dname(rep, i, &j)) {
  				val_find_rrset_signer(rep->rrsets[j],
  					signer_name, signer_len);
  				return;
  			}
  			if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_DNAME)
  				break; /* only check CNAME after a DNAME */
  		}
  		*signer_name = NULL;
  		*signer_len = 0;
  	} else if(subtype == VAL_CLASS_NAMEERROR 
  		|| subtype == VAL_CLASS_NODATA) {
  		/*Check to see if the AUTH section NSEC record(s) have rrsigs*/
  		for(i=rep->an_numrrsets; i<
  			rep->an_numrrsets+rep->ns_numrrsets; i++) {
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC
  				|| ntohs(rep->rrsets[i]->rk.type) ==
  				LDNS_RR_TYPE_NSEC3) {
  				val_find_rrset_signer(rep->rrsets[i], 
  					signer_name, signer_len);
  				return;
  			}
  		}
  	} else if(subtype == VAL_CLASS_CNAMENOANSWER) {
  		/* find closest superdomain signer name in authority section
  		 * NSEC and NSEC3s */
  		int matchcount = 0;
  		*signer_name = NULL;
  		*signer_len = 0;
  		for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->
  			ns_numrrsets; i++) { 
  			if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC
  				|| ntohs(rep->rrsets[i]->rk.type) == 
  				LDNS_RR_TYPE_NSEC3) {
  				val_find_best_signer(rep->rrsets[i], qinf,
  					signer_name, signer_len, &matchcount);
  			}
  		}
  	} else if(subtype == VAL_CLASS_ANY) {
  		/* check for one of the answer rrset that has signatures,
  		 * or potentially a DNAME is in use with a different qname */
  		for(i=skip; i<rep->an_numrrsets; i++) {
  			if(query_dname_compare(qinf->qname, 
  				rep->rrsets[i]->rk.dname) == 0) {
  				val_find_rrset_signer(rep->rrsets[i], 
  					signer_name, signer_len);
  				if(*signer_name)
  					return;
  			}
  		}
  		/* no answer RRSIGs with qname, try a DNAME */
  		if(skip < rep->an_numrrsets &&
  			ntohs(rep->rrsets[skip]->rk.type) ==
  			LDNS_RR_TYPE_DNAME) {
  			val_find_rrset_signer(rep->rrsets[skip], 
  				signer_name, signer_len);
  			if(*signer_name)
  				return;
  		}
  		*signer_name = NULL;
  		*signer_len = 0;
  	} else if(subtype == VAL_CLASS_REFERRAL) {
  		/* find keys for the item at skip */
  		if(skip < rep->rrset_count) {
  			val_find_rrset_signer(rep->rrsets[skip], 
  				signer_name, signer_len);
  			return;
  		}
  		*signer_name = NULL;
  		*signer_len = 0;
  	} else {
  		verbose(VERB_QUERY, "find_signer: could not find signer name"
  			" for unknown type response");
  		*signer_name = NULL;
  		*signer_len = 0;
  	}
  }
  
  /** return number of rrs in an rrset */
  static size_t
  rrset_get_count(struct ub_packed_rrset_key* rrset)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)
  		rrset->entry.data;
  	if(!d) return 0;
  	return d->count;
  }
  
  /** return TTL of rrset */
  static uint32_t
  rrset_get_ttl(struct ub_packed_rrset_key* rrset)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)
  		rrset->entry.data;
  	if(!d) return 0;
  	return d->ttl;
  }
  
  static enum sec_status 
  val_verify_rrset(struct module_env* env, struct val_env* ve,
          struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* keys,
  	uint8_t* sigalg, char** reason, sldns_ede_code *reason_bogus,
  	sldns_pkt_section section, struct module_qstate* qstate,
  	int *verified, char* reasonbuf, size_t reasonlen)
  {
  	enum sec_status sec;
  	struct packed_rrset_data* d = (struct packed_rrset_data*)rrset->
  		entry.data;
  	if(d->security == sec_status_secure) {
  		/* re-verify all other statuses, because keyset may change*/
  		log_nametypeclass(VERB_ALGO, "verify rrset cached", 
  			rrset->rk.dname, ntohs(rrset->rk.type), 
  			ntohs(rrset->rk.rrset_class));
  		*verified = 0;
  		return d->security;
  	}
  	/* check in the cache if verification has already been done */
  	rrset_check_sec_status(env->rrset_cache, rrset, *env->now);
  	if(d->security == sec_status_secure) {
  		log_nametypeclass(VERB_ALGO, "verify rrset from cache", 
  			rrset->rk.dname, ntohs(rrset->rk.type), 
  			ntohs(rrset->rk.rrset_class));
  		*verified = 0;
  		return d->security;
  	}
  	log_nametypeclass(VERB_ALGO, "verify rrset", rrset->rk.dname,
  		ntohs(rrset->rk.type), ntohs(rrset->rk.rrset_class));
  	sec = dnskeyset_verify_rrset(env, ve, rrset, keys, sigalg, reason,
  		reason_bogus, section, qstate, verified, reasonbuf, reasonlen);
  	verbose(VERB_ALGO, "verify result: %s", sec_status_to_string(sec));
  	regional_free_all(env->scratch);
  
  	/* update rrset security status 
  	 * only improves security status 
  	 * and bogus is set only once, even if we rechecked the status */
  	if(sec > d->security) {
  		d->security = sec;
  		if(sec == sec_status_secure)
  			d->trust = rrset_trust_validated;
  		else if(sec == sec_status_bogus) {
  			size_t i;
  			/* update ttl for rrset to fixed value. */
  			d->ttl = ve->bogus_ttl;
  			for(i=0; i<d->count+d->rrsig_count; i++)
  				d->rr_ttl[i] = ve->bogus_ttl;
  			/* leave RR specific TTL: not used for determine
  			 * if RRset timed out and clients see proper value. */
  			lock_basic_lock(&ve->bogus_lock);
  			ve->num_rrset_bogus++;
  			lock_basic_unlock(&ve->bogus_lock);
  		}
  		/* if status updated - store in cache for reuse */
  		rrset_update_sec_status(env->rrset_cache, rrset, *env->now);
  	}
  
  	return sec;
  }
  
  enum sec_status 
  val_verify_rrset_entry(struct module_env* env, struct val_env* ve,
          struct ub_packed_rrset_key* rrset, struct key_entry_key* kkey,
  	char** reason, sldns_ede_code *reason_bogus,
  	sldns_pkt_section section, struct module_qstate* qstate,
  	int* verified, char* reasonbuf, size_t reasonlen)
  {
  	/* temporary dnskey rrset-key */
  	struct ub_packed_rrset_key dnskey;
  	struct key_entry_data* kd = (struct key_entry_data*)kkey->entry.data;
  	enum sec_status sec;
  	dnskey.rk.type = htons(kd->rrset_type);
  	dnskey.rk.rrset_class = htons(kkey->key_class);
  	dnskey.rk.flags = 0;
  	dnskey.rk.dname = kkey->name;
  	dnskey.rk.dname_len = kkey->namelen;
  	dnskey.entry.key = &dnskey;
  	dnskey.entry.data = kd->rrset_data;
  	sec = val_verify_rrset(env, ve, rrset, &dnskey, kd->algo, reason,
  		reason_bogus, section, qstate, verified, reasonbuf, reasonlen);
  	return sec;
  }
  
  /** verify that a DS RR hashes to a key and that key signs the set */
  static enum sec_status
  verify_dnskeys_with_ds_rr(struct module_env* env, struct val_env* ve,
  	struct ub_packed_rrset_key* dnskey_rrset,
          struct ub_packed_rrset_key* ds_rrset, size_t ds_idx, char** reason,
  	sldns_ede_code *reason_bogus, struct module_qstate* qstate,
  	int *nonechecked, char* reasonbuf, size_t reasonlen)
  {
  	enum sec_status sec = sec_status_bogus;
  	size_t i, num, numchecked = 0, numhashok = 0, numsizesupp = 0;
  	num = rrset_get_count(dnskey_rrset);
  	*nonechecked = 0;
  	for(i=0; i<num; i++) {
  		/* Skip DNSKEYs that don't match the basic criteria. */
  		if(ds_get_key_algo(ds_rrset, ds_idx) 
  		   != dnskey_get_algo(dnskey_rrset, i)
  		   || dnskey_calc_keytag(dnskey_rrset, i)
  		   != ds_get_keytag(ds_rrset, ds_idx)) {
  			continue;
  		}
  		numchecked++;
  		verbose(VERB_ALGO, "attempt DS match algo %d keytag %d",
  			ds_get_key_algo(ds_rrset, ds_idx),
  			ds_get_keytag(ds_rrset, ds_idx));
  
  		/* Convert the candidate DNSKEY into a hash using the 
  		 * same DS hash algorithm. */
  		if(!ds_digest_match_dnskey(env, dnskey_rrset, i, ds_rrset, 
  			ds_idx)) {
  			verbose(VERB_ALGO, "DS match attempt failed");
  			if(numchecked > numhashok + MAX_DS_MATCH_FAILURES) {
  				verbose(VERB_ALGO, "DS match attempt reached "
  					"MAX_DS_MATCH_FAILURES (%d); bogus",
  					MAX_DS_MATCH_FAILURES);
  				return sec_status_bogus;
  			}
  			continue;
  		}
  		numhashok++;
  		if(!dnskey_size_is_supported(dnskey_rrset, i)) {
  			verbose(VERB_ALGO, "DS okay but that DNSKEY size is not supported");
  			numsizesupp++;
  			continue;
  		}
  		verbose(VERB_ALGO, "DS match digest ok, trying signature");
  
  		/* Otherwise, we have a match! Make sure that the DNSKEY 
  		 * verifies *with this key*  */
  		sec = dnskey_verify_rrset(env, ve, dnskey_rrset, dnskey_rrset,
  			i, reason, reason_bogus, LDNS_SECTION_ANSWER, qstate);
  		if(sec == sec_status_secure) {
  			return sec;
  		}
  		/* If it didn't validate with the DNSKEY, try the next one! */
  	}
  	if(numsizesupp != 0 || sec == sec_status_indeterminate) {
  		/* there is a working DS, but that DNSKEY is not supported */
  		return sec_status_insecure;
  	}
  	if(numchecked == 0) {
  		algo_needs_reason(ds_get_key_algo(ds_rrset, ds_idx),
  			reason, "no keys have a DS", reasonbuf, reasonlen);
  		*nonechecked = 1;
  	} else if(numhashok == 0) {
  		*reason = "DS hash mismatches key";
  	} else if(!*reason) {
  		*reason = "keyset not secured by DNSKEY that matches DS";
  	}
  	return sec_status_bogus;
  }
  
  int val_favorite_ds_algo(struct ub_packed_rrset_key* ds_rrset)
  {
  	size_t i, num = rrset_get_count(ds_rrset);
  	int d, digest_algo = 0; /* DS digest algo 0 is not used. */
  	/* find favorite algo, for now, highest number supported */
  	for(i=0; i<num; i++) {
  		if(!ds_digest_algo_is_supported(ds_rrset, i) ||
  			!ds_key_algo_is_supported(ds_rrset, i)) {
  			continue;
  		}
  		d = ds_get_digest_algo(ds_rrset, i);
  		if(d > digest_algo)
  			digest_algo = d;
  	}
  	return digest_algo;
  }
  
  enum sec_status
  val_verify_DNSKEY_with_DS(struct module_env* env, struct val_env* ve,
  	struct ub_packed_rrset_key* dnskey_rrset,
  	struct ub_packed_rrset_key* ds_rrset, uint8_t* sigalg, char** reason,
  	sldns_ede_code *reason_bogus, struct module_qstate* qstate,
  	char* reasonbuf, size_t reasonlen)
  {
  	/* as long as this is false, we can consider this DS rrset to be
  	 * equivalent to no DS rrset. */
  	int has_useful_ds = 0, digest_algo, alg, has_algo_refusal = 0,
  		nonechecked, has_checked_ds = 0;
  	struct algo_needs needs;
  	size_t i, num;
  	enum sec_status sec;
  
  	if(dnskey_rrset->rk.dname_len != ds_rrset->rk.dname_len ||
  		query_dname_compare(dnskey_rrset->rk.dname, ds_rrset->rk.dname)
  		!= 0) {
  		verbose(VERB_QUERY, "DNSKEY RRset did not match DS RRset "
  			"by name");
  		*reason = "DNSKEY RRset did not match DS RRset by name";
  		return sec_status_bogus;
  	}
  
  	if(sigalg) {
  		/* harden against algo downgrade is enabled */
  		digest_algo = val_favorite_ds_algo(ds_rrset);
  		algo_needs_init_ds(&needs, ds_rrset, digest_algo, sigalg);
  	} else {
  		/* accept any key algo, any digest algo */
  		digest_algo = -1;
  	}
  	num = rrset_get_count(ds_rrset);
  	for(i=0; i<num; i++) {
  		/* Check to see if we can understand this DS. 
  		 * And check it is the strongest digest */
  		if(!ds_digest_algo_is_supported(ds_rrset, i) ||
  			!ds_key_algo_is_supported(ds_rrset, i) ||
  			(sigalg && (ds_get_digest_algo(ds_rrset, i) != digest_algo))) {
  			continue;
  		}
  
  		sec = verify_dnskeys_with_ds_rr(env, ve, dnskey_rrset,
  			ds_rrset, i, reason, reason_bogus, qstate,
  			&nonechecked, reasonbuf, reasonlen);
  		if(sec == sec_status_insecure) {
  			/* DNSKEY too large unsupported or algo refused by
  			 * crypto lib. */
  			has_algo_refusal = 1;
  			continue;
  		}
  		if(!nonechecked)
  			has_checked_ds = 1;
  
  		/* Once we see a single DS with a known digestID and 
  		 * algorithm, we cannot return INSECURE (with a 
  		 * "null" KeyEntry). */
  		has_useful_ds = 1;
  
  		if(sec == sec_status_secure) {
  			if(!sigalg || algo_needs_set_secure(&needs,
  				(uint8_t)ds_get_key_algo(ds_rrset, i))) {
  				verbose(VERB_ALGO, "DS matched DNSKEY.");
  				if(!dnskeyset_size_is_supported(dnskey_rrset)) {
  					verbose(VERB_ALGO, "DS works, but dnskeyset contain keys that are unsupported, treat as insecure");
  					return sec_status_insecure;
  				}
  				return sec_status_secure;
  			}
  		} else if(sigalg && sec == sec_status_bogus) {
  			algo_needs_set_bogus(&needs,
  				(uint8_t)ds_get_key_algo(ds_rrset, i));
  		}
  	}
  
  	/* None of the DS's worked out. */
  
  	/* If none of the DSes have been checked, eg. that means no matches
  	 * for keytags, and the other dses are all algo_refusal, it is an
  	 * insecure delegation point, since the only matched DS records
  	 * have an algo refusal, or are unsupported. */
  	if(has_algo_refusal && !has_checked_ds) {
  		verbose(VERB_ALGO, "No supported DS records were found -- "
  			"treating as insecure.");
  		return sec_status_insecure;
  	}
  	/* If no DSs were understandable, then this is OK. */
  	if(!has_useful_ds) {
  		verbose(VERB_ALGO, "No usable DS records were found -- "
  			"treating as insecure.");
  		return sec_status_insecure;
  	}
  	/* If any were understandable, then it is bad. */
  	verbose(VERB_QUERY, "Failed to match any usable DS to a DNSKEY.");
  	if(sigalg && (alg=algo_needs_missing(&needs)) != 0) {
  		algo_needs_reason(alg, reason, "missing verification of "
  			"DNSKEY signature", reasonbuf, reasonlen);
  	}
  	return sec_status_bogus;
  }
  
  struct key_entry_key*
  val_verify_new_DNSKEYs(struct regional* region, struct module_env* env, 
  	struct val_env* ve, struct ub_packed_rrset_key* dnskey_rrset, 
  	struct ub_packed_rrset_key* ds_rrset, int downprot, char** reason,
  	sldns_ede_code *reason_bogus, struct module_qstate* qstate,
  	char* reasonbuf, size_t reasonlen)
  {
  	uint8_t sigalg[ALGO_NEEDS_MAX+1];
  	enum sec_status sec = val_verify_DNSKEY_with_DS(env, ve,
  		dnskey_rrset, ds_rrset, downprot?sigalg:NULL, reason, 
  		reason_bogus, qstate, reasonbuf, reasonlen);
  
  	if(sec == sec_status_secure) {
  		return key_entry_create_rrset(region, 
  			ds_rrset->rk.dname, ds_rrset->rk.dname_len,
  			ntohs(ds_rrset->rk.rrset_class), dnskey_rrset,
  			downprot?sigalg:NULL, LDNS_EDE_NONE, NULL,
  			*env->now);
  	} else if(sec == sec_status_insecure) {
  		return key_entry_create_null(region, ds_rrset->rk.dname,
  			ds_rrset->rk.dname_len,
  			ntohs(ds_rrset->rk.rrset_class),
  			rrset_get_ttl(ds_rrset), *reason_bogus, *reason,
  			*env->now);
  	}
  	return key_entry_create_bad(region, ds_rrset->rk.dname,
  		ds_rrset->rk.dname_len, ntohs(ds_rrset->rk.rrset_class),
  		BOGUS_KEY_TTL, *reason_bogus, *reason, *env->now);
  }
  
  enum sec_status
  val_verify_DNSKEY_with_TA(struct module_env* env, struct val_env* ve,
  	struct ub_packed_rrset_key* dnskey_rrset,
  	struct ub_packed_rrset_key* ta_ds,
  	struct ub_packed_rrset_key* ta_dnskey, uint8_t* sigalg, char** reason,
  	sldns_ede_code *reason_bogus, struct module_qstate* qstate,
  	char* reasonbuf, size_t reasonlen)
  {
  	/* as long as this is false, we can consider this anchor to be
  	 * equivalent to no anchor. */
  	int has_useful_ta = 0, digest_algo = 0, alg, has_algo_refusal = 0,
  		nonechecked, has_checked_ds = 0;
  	struct algo_needs needs;
  	size_t i, num;
  	enum sec_status sec;
  
  	if(ta_ds && (dnskey_rrset->rk.dname_len != ta_ds->rk.dname_len ||
  		query_dname_compare(dnskey_rrset->rk.dname, ta_ds->rk.dname)
  		!= 0)) {
  		verbose(VERB_QUERY, "DNSKEY RRset did not match DS RRset "
  			"by name");
  		*reason = "DNSKEY RRset did not match DS RRset by name";
  		if(reason_bogus)
  			*reason_bogus = LDNS_EDE_DNSKEY_MISSING;
  		return sec_status_bogus;
  	}
  	if(ta_dnskey && (dnskey_rrset->rk.dname_len != ta_dnskey->rk.dname_len
  	     || query_dname_compare(dnskey_rrset->rk.dname, ta_dnskey->rk.dname)
  		!= 0)) {
  		verbose(VERB_QUERY, "DNSKEY RRset did not match anchor RRset "
  			"by name");
  		*reason = "DNSKEY RRset did not match anchor RRset by name";
  		if(reason_bogus)
  			*reason_bogus = LDNS_EDE_DNSKEY_MISSING;
  		return sec_status_bogus;
  	}
  
  	if(ta_ds)
  		digest_algo = val_favorite_ds_algo(ta_ds);
  	if(sigalg) {
  		if(ta_ds)
  			algo_needs_init_ds(&needs, ta_ds, digest_algo, sigalg);
  		else	memset(&needs, 0, sizeof(needs));
  		if(ta_dnskey)
  			algo_needs_init_dnskey_add(&needs, ta_dnskey, sigalg);
  	}
  	if(ta_ds) {
  	    num = rrset_get_count(ta_ds);
  	    for(i=0; i<num; i++) {
  		/* Check to see if we can understand this DS. 
  		 * And check it is the strongest digest */
  		if(!ds_digest_algo_is_supported(ta_ds, i) ||
  			!ds_key_algo_is_supported(ta_ds, i) ||
  			ds_get_digest_algo(ta_ds, i) != digest_algo)
  			continue;
  
  		sec = verify_dnskeys_with_ds_rr(env, ve, dnskey_rrset,
  			ta_ds, i, reason, reason_bogus, qstate, &nonechecked,
  			reasonbuf, reasonlen);
  		if(sec == sec_status_insecure) {
  			has_algo_refusal = 1;
  			continue;
  		}
  		if(!nonechecked)
  			has_checked_ds = 1;
  
  		/* Once we see a single DS with a known digestID and 
  		 * algorithm, we cannot return INSECURE (with a 
  		 * "null" KeyEntry). */
  		has_useful_ta = 1;
  
  		if(sec == sec_status_secure) {
  			if(!sigalg || algo_needs_set_secure(&needs,
  				(uint8_t)ds_get_key_algo(ta_ds, i))) {
  				verbose(VERB_ALGO, "DS matched DNSKEY.");
  				if(!dnskeyset_size_is_supported(dnskey_rrset)) {
  					verbose(VERB_ALGO, "trustanchor works, but dnskeyset contain keys that are unsupported, treat as insecure");
  					return sec_status_insecure;
  				}
  				return sec_status_secure;
  			}
  		} else if(sigalg && sec == sec_status_bogus) {
  			algo_needs_set_bogus(&needs,
  				(uint8_t)ds_get_key_algo(ta_ds, i));
  		}
  	    }
  	}
  
  	/* None of the DS's worked out: check the DNSKEYs. */
  	if(ta_dnskey) {
  	    num = rrset_get_count(ta_dnskey);
  	    for(i=0; i<num; i++) {
  		/* Check to see if we can understand this DNSKEY */
  		if(!dnskey_algo_is_supported(ta_dnskey, i))
  			continue;
  		if(!dnskey_size_is_supported(ta_dnskey, i))
  			continue;
  
  		/* we saw a useful TA */
  		has_useful_ta = 1;
  
  		sec = dnskey_verify_rrset(env, ve, dnskey_rrset,
  			ta_dnskey, i, reason, reason_bogus, LDNS_SECTION_ANSWER, qstate);
  		if(sec == sec_status_secure) {
  			if(!sigalg || algo_needs_set_secure(&needs,
  				(uint8_t)dnskey_get_algo(ta_dnskey, i))) {
  				verbose(VERB_ALGO, "anchor matched DNSKEY.");
  				if(!dnskeyset_size_is_supported(dnskey_rrset)) {
  					verbose(VERB_ALGO, "trustanchor works, but dnskeyset contain keys that are unsupported, treat as insecure");
  					return sec_status_insecure;
  				}
  				return sec_status_secure;
  			}
  		} else if(sigalg && sec == sec_status_bogus) {
  			algo_needs_set_bogus(&needs,
  				(uint8_t)dnskey_get_algo(ta_dnskey, i));
  		}
  	    }
  	}
  
  	/* If none of the DSes have been checked, eg. that means no matches
  	 * for keytags, and the other dses are all algo_refusal, it is an
  	 * insecure delegation point, since the only matched DS records
  	 * have an algo refusal, or are unsupported. */
  	if(has_algo_refusal && !has_checked_ds) {
  		verbose(VERB_ALGO, "No supported trust anchors were found -- "
  			"treating as insecure.");
  		return sec_status_insecure;
  	}
  	/* If no DSs were understandable, then this is OK. */
  	if(!has_useful_ta) {
  		verbose(VERB_ALGO, "No usable trust anchors were found -- "
  			"treating as insecure.");
  		return sec_status_insecure;
  	}
  	/* If any were understandable, then it is bad. */
  	verbose(VERB_QUERY, "Failed to match any usable anchor to a DNSKEY.");
  	if(sigalg && (alg=algo_needs_missing(&needs)) != 0) {
  		algo_needs_reason(alg, reason, "missing verification of "
  			"DNSKEY signature", reasonbuf, reasonlen);
  	}
  	return sec_status_bogus;
  }
  
  struct key_entry_key* 
  val_verify_new_DNSKEYs_with_ta(struct regional* region, struct module_env* env,
  	struct val_env* ve, struct ub_packed_rrset_key* dnskey_rrset,
  	struct ub_packed_rrset_key* ta_ds_rrset,
  	struct ub_packed_rrset_key* ta_dnskey_rrset, int downprot,
  	char** reason, sldns_ede_code *reason_bogus,
  	struct module_qstate* qstate, char* reasonbuf, size_t reasonlen)
  {
  	uint8_t sigalg[ALGO_NEEDS_MAX+1];
  	enum sec_status sec = val_verify_DNSKEY_with_TA(env, ve,
  		dnskey_rrset, ta_ds_rrset, ta_dnskey_rrset,
  		downprot?sigalg:NULL, reason, reason_bogus, qstate,
  		reasonbuf, reasonlen);
  
  	if(sec == sec_status_secure) {
  		return key_entry_create_rrset(region,
  			dnskey_rrset->rk.dname, dnskey_rrset->rk.dname_len,
  			ntohs(dnskey_rrset->rk.rrset_class), dnskey_rrset,
  			downprot?sigalg:NULL, LDNS_EDE_NONE, NULL, *env->now);
  	} else if(sec == sec_status_insecure) {
  		return key_entry_create_null(region, dnskey_rrset->rk.dname,
  			dnskey_rrset->rk.dname_len,
  			ntohs(dnskey_rrset->rk.rrset_class),
  			rrset_get_ttl(dnskey_rrset), *reason_bogus, *reason,
  			*env->now);
  	}
  	return key_entry_create_bad(region, dnskey_rrset->rk.dname,
  		dnskey_rrset->rk.dname_len, ntohs(dnskey_rrset->rk.rrset_class),
  		BOGUS_KEY_TTL, *reason_bogus, *reason, *env->now);
  }
  
  int
  val_dsset_isusable(struct ub_packed_rrset_key* ds_rrset)
  {
  	size_t i;
  	for(i=0; i<rrset_get_count(ds_rrset); i++) {
  		if(ds_digest_algo_is_supported(ds_rrset, i) &&
  			ds_key_algo_is_supported(ds_rrset, i))
  			return 1;
  	}
  	if(verbosity < VERB_ALGO)
  		return 0;
  	if(rrset_get_count(ds_rrset) == 0)
  		verbose(VERB_ALGO, "DS is not usable");
  	else {
  		/* report usability for the first DS RR */
  		sldns_lookup_table *lt;
  		char herr[64], aerr[64];
  		lt = sldns_lookup_by_id(sldns_hashes,
  			(int)ds_get_digest_algo(ds_rrset, 0));
  		if(lt) snprintf(herr, sizeof(herr), "%s", lt->name);
  		else snprintf(herr, sizeof(herr), "%d",
  			(int)ds_get_digest_algo(ds_rrset, 0));
  		lt = sldns_lookup_by_id(sldns_algorithms,
  			(int)ds_get_key_algo(ds_rrset, 0));
  		if(lt) snprintf(aerr, sizeof(aerr), "%s", lt->name);
  		else snprintf(aerr, sizeof(aerr), "%d",
  			(int)ds_get_key_algo(ds_rrset, 0));
  
  		verbose(VERB_ALGO, "DS unsupported, hash %s %s, "
  			"key algorithm %s %s", herr,
  			(ds_digest_algo_is_supported(ds_rrset, 0)?
  			"(supported)":"(unsupported)"), aerr, 
  			(ds_key_algo_is_supported(ds_rrset, 0)?
  			"(supported)":"(unsupported)"));
  	}
  	return 0;
  }
  
  /** get label count for a signature */
  static uint8_t
  rrsig_get_labcount(struct packed_rrset_data* d, size_t sig)
  {
  	if(d->rr_len[sig] < 2+4)
  		return 0; /* bad sig length */
  	return d->rr_data[sig][2+3];
  }
  
  int 
  val_rrset_wildcard(struct ub_packed_rrset_key* rrset, uint8_t** wc,
  	size_t* wc_len)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)rrset->
  		entry.data;
  	uint8_t labcount;
  	int labdiff;
  	uint8_t* wn;
  	size_t i, wl;
  	if(d->rrsig_count == 0) {
  		return 1;
  	}
  	labcount = rrsig_get_labcount(d, d->count + 0);
  	/* check rest of signatures identical */
  	for(i=1; i<d->rrsig_count; i++) {
  		if(labcount != rrsig_get_labcount(d, d->count + i)) {
  			return 0;
  		}
  	}
  	/* OK the rrsigs check out */
  	/* if the RRSIG label count is shorter than the number of actual 
  	 * labels, then this rrset was synthesized from a wildcard.
  	 * Note that the RRSIG label count doesn't count the root label. */
  	wn = rrset->rk.dname;
  	wl = rrset->rk.dname_len;
  	/* skip a leading wildcard label in the dname (RFC4035 2.2) */
  	if(dname_is_wild(wn)) {
  		wn += 2;
  		wl -= 2;
  	}
  	labdiff = (dname_count_labels(wn) - 1) - (int)labcount;
  	if(labdiff > 0) {
  		*wc = wn;
  		dname_remove_labels(wc, &wl, labdiff);
  		*wc_len = wl;
  		return 1;
  	}
  	return 1;
  }
  
  int
  val_chase_cname(struct query_info* qchase, struct reply_info* rep,
  	size_t* cname_skip) {
  	size_t i;
  	/* skip any DNAMEs, go to the CNAME for next part */
  	for(i = *cname_skip; i < rep->an_numrrsets; i++) {
  		if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME &&
  			query_dname_compare(qchase->qname, rep->rrsets[i]->
  				rk.dname) == 0) {
  			qchase->qname = NULL;
  			get_cname_target(rep->rrsets[i], &qchase->qname,
  				&qchase->qname_len);
  			if(!qchase->qname)
  				return 0; /* bad CNAME rdata */
  			(*cname_skip) = i+1;
  			return 1;
  		}
  	}
  	return 0; /* CNAME classified but no matching CNAME ?! */
  }
  
  /** see if rrset has signer name as one of the rrsig signers */
  static int
  rrset_has_signer(struct ub_packed_rrset_key* rrset, uint8_t* name, size_t len)
  {
  	struct packed_rrset_data* d = (struct packed_rrset_data*)rrset->
  		entry.data;
  	size_t i;
  	for(i = d->count; i< d->count+d->rrsig_count; i++) {
  		if(d->rr_len[i] > 2+18+len) {
  			/* at least rdatalen + signature + signame (+1 sig)*/
  			if(!dname_valid(d->rr_data[i]+2+18, d->rr_len[i]-2-18))
  				continue;
  			if(query_dname_compare(name, d->rr_data[i]+2+18) == 0)
  			{
  				return 1;
  			}
  		}
  	}
  	return 0;
  }
  
  void 
  val_fill_reply(struct reply_info* chase, struct reply_info* orig, 
  	size_t skip, uint8_t* name, size_t len, uint8_t* signer)
  {
  	size_t i, j;
  	int seen_dname = 0;
  	chase->rrset_count = 0;
  	chase->an_numrrsets = 0;
  	chase->ns_numrrsets = 0;
  	chase->ar_numrrsets = 0;
  	/* ANSWER section */
  	for(i=skip; i<orig->an_numrrsets; i++) {
  		if(!signer) {
  			if(query_dname_compare(name, 
  				orig->rrsets[i]->rk.dname) == 0)
  				chase->rrsets[chase->an_numrrsets++] = 
  					orig->rrsets[i];
  		} else if(seen_dname && ntohs(orig->rrsets[i]->rk.type) == 
  			LDNS_RR_TYPE_CNAME) {
  			chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i];
  			seen_dname = 0;
  		} else if(rrset_has_signer(orig->rrsets[i], name, len)) {
  			chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i];
  			if(ntohs(orig->rrsets[i]->rk.type) == 
  				LDNS_RR_TYPE_DNAME) {
  					seen_dname = 1;
  			}
  		} else if(ntohs(orig->rrsets[i]->rk.type) == LDNS_RR_TYPE_CNAME
  			&& ((struct packed_rrset_data*)orig->rrsets[i]->
  			entry.data)->rrsig_count == 0 &&
  			cname_under_previous_dname(orig, i, &j) &&
  			rrset_has_signer(orig->rrsets[j], name, len)) {
  			chase->rrsets[chase->an_numrrsets++] = orig->rrsets[j];
  			chase->rrsets[chase->an_numrrsets++] = orig->rrsets[i];
  		}
  	}	
  	/* AUTHORITY section */
  	for(i = (skip > orig->an_numrrsets)?skip:orig->an_numrrsets;
  		i<orig->an_numrrsets+orig->ns_numrrsets; 
  		i++) {
  		if(!signer) {
  			if(query_dname_compare(name, 
  				orig->rrsets[i]->rk.dname) == 0)
  				chase->rrsets[chase->an_numrrsets+
  				    chase->ns_numrrsets++] = orig->rrsets[i];
  		} else if(rrset_has_signer(orig->rrsets[i], name, len)) {
  			chase->rrsets[chase->an_numrrsets+
  				chase->ns_numrrsets++] = orig->rrsets[i];
  		}
  	}
  	/* ADDITIONAL section */
  	for(i= (skip>orig->an_numrrsets+orig->ns_numrrsets)?
  		skip:orig->an_numrrsets+orig->ns_numrrsets; 
  		i<orig->rrset_count; i++) {
  		if(!signer) {
  			if(query_dname_compare(name, 
  				orig->rrsets[i]->rk.dname) == 0)
  			    chase->rrsets[chase->an_numrrsets
  				+chase->ns_numrrsets+chase->ar_numrrsets++]
  				= orig->rrsets[i];
  		} else if(rrset_has_signer(orig->rrsets[i], name, len)) {
  			chase->rrsets[chase->an_numrrsets+chase->ns_numrrsets+
  				chase->ar_numrrsets++] = orig->rrsets[i];
  		}
  	}
  	chase->rrset_count = chase->an_numrrsets + chase->ns_numrrsets + 
  		chase->ar_numrrsets;
  }
  
  void val_reply_remove_auth(struct reply_info* rep, size_t index)
  {
  	log_assert(index < rep->rrset_count);
  	log_assert(index >= rep->an_numrrsets);
  	log_assert(index < rep->an_numrrsets+rep->ns_numrrsets);
  	memmove(rep->rrsets+index, rep->rrsets+index+1,
  		sizeof(struct ub_packed_rrset_key*)*
  		(rep->rrset_count - index - 1));
  	rep->ns_numrrsets--;
  	rep->rrset_count--;
  }
  
  void
  val_check_nonsecure(struct module_env* env, struct reply_info* rep) 
  {
  	size_t i;
  	/* authority */
  	for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
  		if(((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
  			->security != sec_status_secure) {
  			/* because we want to return the authentic original
  			 * message when presented with CD-flagged queries,
  			 * we need to preserve AUTHORITY section data.
  			 * However, this rrset is not signed or signed
  			 * with the wrong keys. Validation has tried to
  			 * verify this rrset with the keysets of import.
  			 * But this rrset did not verify.
  			 * Therefore the message is bogus.
  			 */
  
  			/* check if authority has an NS record
  			 * which is bad, and there is an answer section with
  			 * data.  In that case, delete NS and additional to 
  			 * be lenient and make a minimal response */
  			if(rep->an_numrrsets != 0 &&
  				ntohs(rep->rrsets[i]->rk.type) 
  				== LDNS_RR_TYPE_NS) {
  				verbose(VERB_ALGO, "truncate to minimal");
  				rep->ar_numrrsets = 0;
  				rep->rrset_count = rep->an_numrrsets +
  					rep->ns_numrrsets;
  				/* remove this unneeded authority rrset */
  				memmove(rep->rrsets+i, rep->rrsets+i+1, 
  					sizeof(struct ub_packed_rrset_key*)*
  					(rep->rrset_count - i - 1));
  				rep->ns_numrrsets--;
  				rep->rrset_count--;
  				i--;
  				return;
  			}
  
  			log_nametypeclass(VERB_QUERY, "message is bogus, "
  				"non secure rrset",
  				rep->rrsets[i]->rk.dname, 
  				ntohs(rep->rrsets[i]->rk.type),
  				ntohs(rep->rrsets[i]->rk.rrset_class));
  			rep->security = sec_status_bogus;
  			return;
  		}
  	}
  	/* additional */
  	if(!env->cfg->val_clean_additional)
  		return;
  	for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
  		if(((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
  			->security != sec_status_secure) {
  			/* This does not cause message invalidation. It was
  			 * simply unsigned data in the additional. The
  			 * RRSIG must have been truncated off the message.
  			 *
  			 * However, we do not want to return possible bogus
  			 * data to clients that rely on this service for
  			 * their authentication.
  			 */
  			/* remove this unneeded additional rrset */
  			memmove(rep->rrsets+i, rep->rrsets+i+1, 
  				sizeof(struct ub_packed_rrset_key*)*
  				(rep->rrset_count - i - 1));
  			rep->ar_numrrsets--;
  			rep->rrset_count--;
  			i--;
  		}
  	}
  }
  
  /** check no anchor and unlock */
  static int
  check_no_anchor(struct val_anchors* anchors, uint8_t* nm, size_t l, uint16_t c)
  {
  	struct trust_anchor* ta;
  	if((ta=anchors_lookup(anchors, nm, l, c))) {
  		lock_basic_unlock(&ta->lock);
  	}
  	return !ta;
  }
  
  void 
  val_mark_indeterminate(struct reply_info* rep, struct val_anchors* anchors, 
  	struct rrset_cache* r, struct module_env* env)
  {
  	size_t i;
  	struct packed_rrset_data* d;
  	for(i=0; i<rep->rrset_count; i++) {
  		d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
  		if(d->security == sec_status_unchecked &&
  		   check_no_anchor(anchors, rep->rrsets[i]->rk.dname,
  			rep->rrsets[i]->rk.dname_len, 
  			ntohs(rep->rrsets[i]->rk.rrset_class))) 
  		{ 	
  			/* mark as indeterminate */
  			d->security = sec_status_indeterminate;
  			rrset_update_sec_status(r, rep->rrsets[i], *env->now);
  		}
  	}
  }
  
  void 
  val_mark_insecure(struct reply_info* rep, uint8_t* kname,
  	struct rrset_cache* r, struct module_env* env)
  {
  	size_t i;
  	struct packed_rrset_data* d;
  	for(i=0; i<rep->rrset_count; i++) {
  		d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
  		if(d->security == sec_status_unchecked &&
  		   dname_subdomain_c(rep->rrsets[i]->rk.dname, kname)) {
  			/* mark as insecure */
  			d->security = sec_status_insecure;
  			rrset_update_sec_status(r, rep->rrsets[i], *env->now);
  		}
  	}
  }
  
  size_t 
  val_next_unchecked(struct reply_info* rep, size_t skip)
  {
  	size_t i;
  	struct packed_rrset_data* d;
  	for(i=skip+1; i<rep->rrset_count; i++) {
  		d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
  		if(d->security == sec_status_unchecked) {
  			return i;
  		}
  	}
  	return rep->rrset_count;
  }
  
  const char*
  val_classification_to_string(enum val_classification subtype)
  {
  	switch(subtype) {
  		case VAL_CLASS_UNTYPED: 	return "untyped";
  		case VAL_CLASS_UNKNOWN: 	return "unknown";
  		case VAL_CLASS_POSITIVE: 	return "positive";
  		case VAL_CLASS_CNAME: 		return "cname";
  		case VAL_CLASS_NODATA: 		return "nodata";
  		case VAL_CLASS_NAMEERROR: 	return "nameerror";
  		case VAL_CLASS_CNAMENOANSWER: 	return "cnamenoanswer";
  		case VAL_CLASS_REFERRAL: 	return "referral";
  		case VAL_CLASS_ANY: 		return "qtype_any";
  		default:
  			return "bad_val_classification";
  	}
  }
  
  /** log a sock_list entry */
  static void
  sock_list_logentry(enum verbosity_value v, const char* s, struct sock_list* p)
  {
  	if(p->len)
  		log_addr(v, s, &p->addr, p->len);
  	else	verbose(v, "%s cache", s);
  }
  
  void val_blacklist(struct sock_list** blacklist, struct regional* region,
  	struct sock_list* origin, int cross)
  {
  	/* debug printout */
  	if(verbosity >= VERB_ALGO) {
  		struct sock_list* p;
  		for(p=*blacklist; p; p=p->next)
  			sock_list_logentry(VERB_ALGO, "blacklist", p);
  		if(!origin)
  			verbose(VERB_ALGO, "blacklist add: cache");
  		for(p=origin; p; p=p->next)
  			sock_list_logentry(VERB_ALGO, "blacklist add", p);
  	}
  	/* blacklist the IPs or the cache */
  	if(!origin) {
  		/* only add if nothing there. anything else also stops cache*/
  		if(!*blacklist)
  			sock_list_insert(blacklist, NULL, 0, region);
  	} else if(!cross)
  		sock_list_prepend(blacklist, origin);
  	else	sock_list_merge(blacklist, region, origin);
  }
  
  int val_has_signed_nsecs(struct reply_info* rep, char** reason)
  {
  	size_t i, num_nsec = 0, num_nsec3 = 0;
  	struct packed_rrset_data* d;
  	for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
  		if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC))
  			num_nsec++;
  		else if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NSEC3))
  			num_nsec3++;
  		else continue;
  		d = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
  		if(d && d->rrsig_count != 0) {
  			return 1;
  		}
  	}
  	if(num_nsec == 0 && num_nsec3 == 0)
  		*reason = "no DNSSEC records";
  	else if(num_nsec != 0)
  		*reason = "no signatures over NSECs";
  	else	*reason = "no signatures over NSEC3s";
  	return 0;
  }
  
  struct dns_msg* 
  val_find_DS(struct module_env* env, uint8_t* nm, size_t nmlen, uint16_t c, 
  	struct regional* region, uint8_t* topname)
  {
  	struct dns_msg* msg;
  	struct query_info qinfo;
  	struct ub_packed_rrset_key *rrset = rrset_cache_lookup(
  		env->rrset_cache, nm, nmlen, LDNS_RR_TYPE_DS, c, 0, 
  		*env->now, 0);
  	if(rrset) {
  		/* DS rrset exists. Return it to the validator immediately*/
  		struct ub_packed_rrset_key* copy = packed_rrset_copy_region(
  			rrset, region, *env->now);
  		struct packed_rrset_data* d = copy->entry.data;
  		lock_rw_unlock(&rrset->entry.lock);
  		if(!copy)
  			return NULL;
  		msg = dns_msg_create(nm, nmlen, LDNS_RR_TYPE_DS, c, region, 1);
  		if(!msg)
  			return NULL;
  		msg->rep->rrsets[0] = copy;
  		msg->rep->rrset_count++;
  		msg->rep->an_numrrsets++;
  		UPDATE_TTL_FROM_RRSET(msg->rep->ttl, d->ttl);
  		return msg;
  	}
  	/* lookup in rrset and negative cache for NSEC/NSEC3 */
  	qinfo.qname = nm;
  	qinfo.qname_len = nmlen;
  	qinfo.qtype = LDNS_RR_TYPE_DS;
  	qinfo.qclass = c;
  	qinfo.local_alias = NULL;
  	/* do not add SOA to reply message, it is going to be used internal */
  	msg = val_neg_getmsg(env->neg_cache, &qinfo, region, env->rrset_cache,
  		env->scratch_buffer, *env->now, 0, topname, env->cfg);
  	return msg;
  }
  
  int derive_cname_from_dname(struct ub_packed_rrset_key* cname,
  	struct ub_packed_rrset_key* dname, uint8_t* out, size_t outlen)
  {
  	size_t prefix_len;
  	uint8_t* dname_target = NULL;
  	size_t dname_target_len = 0;
  	if(!dname_strict_subdomain_c(cname->rk.dname, dname->rk.dname))
  		return 0; /* Invalid: CNAME owner must be subdomain */
  	get_cname_target(dname, &dname_target, &dname_target_len);
  	if(!dname_target || !dname_target_len)
  		return 0; /* DNAME malformed */
  	if(cname->rk.dname_len < dname->rk.dname_len)
  		return 0; /* Not possible, due to subdomain, but check */
  	if(cname->rk.dname_len == 0)
  		return 0; /* Not possible, but check */
  	prefix_len = cname->rk.dname_len - dname->rk.dname_len;
  	if(prefix_len + dname_target_len > outlen)
  		return 0; /* Buffer too small */
  	memmove(out, cname->rk.dname, prefix_len);
  	memmove(out+prefix_len, dname_target, dname_target_len);
  	return 1;
  }