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[FreeBSD/FreeBSD.git] / contrib / unbound / validator / validator.c

/*
 * validator/validator.c - secure validator DNS query response module
 *
 * 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 a module that performs validation of DNS queries.
 * According to RFC 4034.
 */
#include "config.h"
#include "validator/validator.h"
#include "validator/val_anchor.h"
#include "validator/val_kcache.h"
#include "validator/val_kentry.h"
#include "validator/val_utils.h"
#include "validator/val_nsec.h"
#include "validator/val_nsec3.h"
#include "validator/val_neg.h"
#include "validator/val_sigcrypt.h"
#include "validator/autotrust.h"
#include "services/cache/dns.h"
#include "util/data/dname.h"
#include "util/module.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/regional.h"
#include "util/config_file.h"
#include "util/fptr_wlist.h"
#include "sldns/rrdef.h"
#include "sldns/wire2str.h"

/* forward decl for cache response and normal super inform calls of a DS */
static void process_ds_response(struct module_qstate* qstate, 
        struct val_qstate* vq, int id, int rcode, struct dns_msg* msg, 
        struct query_info* qinfo, struct sock_list* origin);

/** fill up nsec3 key iterations config entry */
static int
fill_nsec3_iter(struct val_env* ve, char* s, int c)
{
        char* e;
        int i;
        free(ve->nsec3_keysize);
        free(ve->nsec3_maxiter);
        ve->nsec3_keysize = (size_t*)calloc(sizeof(size_t), (size_t)c);
        ve->nsec3_maxiter = (size_t*)calloc(sizeof(size_t), (size_t)c);
        if(!ve->nsec3_keysize || !ve->nsec3_maxiter) {
                log_err("out of memory");
                return 0;
        }
        for(i=0; i<c; i++) {
                ve->nsec3_keysize[i] = (size_t)strtol(s, &e, 10);
                if(s == e) {
                        log_err("cannot parse: %s", s);
                        return 0;
                }
                s = e;
                ve->nsec3_maxiter[i] = (size_t)strtol(s, &e, 10);
                if(s == e) {
                        log_err("cannot parse: %s", s);
                        return 0;
                }
                s = e;
                if(i>0 && ve->nsec3_keysize[i-1] >= ve->nsec3_keysize[i]) {
                        log_err("nsec3 key iterations not ascending: %d %d",
                                (int)ve->nsec3_keysize[i-1], 
                                (int)ve->nsec3_keysize[i]);
                        return 0;
                }
                verbose(VERB_ALGO, "validator nsec3cfg keysz %d mxiter %d",
                        (int)ve->nsec3_keysize[i], (int)ve->nsec3_maxiter[i]);
        }
        return 1;
}

/** apply config settings to validator */
static int
val_apply_cfg(struct module_env* env, struct val_env* val_env, 
        struct config_file* cfg)
{
        int c;
        val_env->bogus_ttl = (uint32_t)cfg->bogus_ttl;
        val_env->clean_additional = cfg->val_clean_additional;
        val_env->permissive_mode = cfg->val_permissive_mode;
        if(!env->anchors)
                env->anchors = anchors_create();
        if(!env->anchors) {
                log_err("out of memory");
                return 0;
        }
        if(!val_env->kcache)
                val_env->kcache = key_cache_create(cfg);
        if(!val_env->kcache) {
                log_err("out of memory");
                return 0;
        }
        env->key_cache = val_env->kcache;
        if(!anchors_apply_cfg(env->anchors, cfg)) {
                log_err("validator: error in trustanchors config");
                return 0;
        }
        val_env->date_override = cfg->val_date_override;
        val_env->skew_min = cfg->val_sig_skew_min;
        val_env->skew_max = cfg->val_sig_skew_max;
        c = cfg_count_numbers(cfg->val_nsec3_key_iterations);
        if(c < 1 || (c&1)) {
                log_err("validator: unparseable or odd nsec3 key "
                        "iterations: %s", cfg->val_nsec3_key_iterations);
                return 0;
        }
        val_env->nsec3_keyiter_count = c/2;
        if(!fill_nsec3_iter(val_env, cfg->val_nsec3_key_iterations, c/2)) {
                log_err("validator: cannot apply nsec3 key iterations");
                return 0;
        }
        if(!val_env->neg_cache)
                val_env->neg_cache = val_neg_create(cfg,
                        val_env->nsec3_maxiter[val_env->nsec3_keyiter_count-1]);
        if(!val_env->neg_cache) {
                log_err("out of memory");
                return 0;
        }
        env->neg_cache = val_env->neg_cache;
        return 1;
}

#ifdef USE_ECDSA_EVP_WORKAROUND
void ecdsa_evp_workaround_init(void);
#endif
int
val_init(struct module_env* env, int id)
{
        struct val_env* val_env = (struct val_env*)calloc(1,
                sizeof(struct val_env));
        if(!val_env) {
                log_err("malloc failure");
                return 0;
        }
        env->modinfo[id] = (void*)val_env;
        env->need_to_validate = 1;
        val_env->permissive_mode = 0;
        lock_basic_init(&val_env->bogus_lock);
        lock_protect(&val_env->bogus_lock, &val_env->num_rrset_bogus,
                sizeof(val_env->num_rrset_bogus));
#ifdef USE_ECDSA_EVP_WORKAROUND
        ecdsa_evp_workaround_init();
#endif
        if(!val_apply_cfg(env, val_env, env->cfg)) {
                log_err("validator: could not apply configuration settings.");
                return 0;
        }

        return 1;
}

void
val_deinit(struct module_env* env, int id)
{
        struct val_env* val_env;
        if(!env || !env->modinfo[id])
                return;
        val_env = (struct val_env*)env->modinfo[id];
        lock_basic_destroy(&val_env->bogus_lock);
        anchors_delete(env->anchors);
        env->anchors = NULL;
        key_cache_delete(val_env->kcache);
        neg_cache_delete(val_env->neg_cache);
        free(val_env->nsec3_keysize);
        free(val_env->nsec3_maxiter);
        free(val_env);
        env->modinfo[id] = NULL;
}

/** fill in message structure */
static struct val_qstate*
val_new_getmsg(struct module_qstate* qstate, struct val_qstate* vq)
{
        if(!qstate->return_msg || qstate->return_rcode != LDNS_RCODE_NOERROR) {
                /* create a message to verify */
                verbose(VERB_ALGO, "constructing reply for validation");
                vq->orig_msg = (struct dns_msg*)regional_alloc(qstate->region,
                        sizeof(struct dns_msg));
                if(!vq->orig_msg)
                        return NULL;
                vq->orig_msg->qinfo = qstate->qinfo;
                vq->orig_msg->rep = (struct reply_info*)regional_alloc(
                        qstate->region, sizeof(struct reply_info));
                if(!vq->orig_msg->rep)
                        return NULL;
                memset(vq->orig_msg->rep, 0, sizeof(struct reply_info));
                vq->orig_msg->rep->flags = (uint16_t)(qstate->return_rcode&0xf)
                        |BIT_QR|BIT_RA|(qstate->query_flags|(BIT_CD|BIT_RD));
                vq->orig_msg->rep->qdcount = 1;
        } else {
                vq->orig_msg = qstate->return_msg;
        }
        vq->qchase = qstate->qinfo;
        /* chase reply will be an edited (sub)set of the orig msg rrset ptrs */
        vq->chase_reply = regional_alloc_init(qstate->region, 
                vq->orig_msg->rep, 
                sizeof(struct reply_info) - sizeof(struct rrset_ref));
        if(!vq->chase_reply)
                return NULL;
        if(vq->orig_msg->rep->rrset_count > RR_COUNT_MAX)
                return NULL; /* protect against integer overflow */
        vq->chase_reply->rrsets = regional_alloc_init(qstate->region,
                vq->orig_msg->rep->rrsets, sizeof(struct ub_packed_rrset_key*)
                        * vq->orig_msg->rep->rrset_count);
        if(!vq->chase_reply->rrsets)
                return NULL;
        vq->rrset_skip = 0;
        return vq;
}

/** allocate new validator query state */
static struct val_qstate*
val_new(struct module_qstate* qstate, int id)
{
        struct val_qstate* vq = (struct val_qstate*)regional_alloc(
                qstate->region, sizeof(*vq));
        log_assert(!qstate->minfo[id]);
        if(!vq)
                return NULL;
        memset(vq, 0, sizeof(*vq));
        qstate->minfo[id] = vq;
        vq->state = VAL_INIT_STATE;
        return val_new_getmsg(qstate, vq);
}

/**
 * Exit validation with an error status
 * 
 * @param qstate: query state
 * @param id: validator id.
 * @return false, for use by caller to return to stop processing.
 */
static int
val_error(struct module_qstate* qstate, int id)
{
        qstate->ext_state[id] = module_error;
        qstate->return_rcode = LDNS_RCODE_SERVFAIL;
        return 0;
}

/** 
 * Check to see if a given response needs to go through the validation
 * process. Typical reasons for this routine to return false are: CD bit was
 * on in the original request, or the response is a kind of message that 
 * is unvalidatable (i.e., SERVFAIL, REFUSED, etc.)
 *
 * @param qstate: query state.
 * @param ret_rc: rcode for this message (if noerror - examine ret_msg).
 * @param ret_msg: return msg, can be NULL; look at rcode instead.
 * @return true if the response could use validation (although this does not
 *         mean we can actually validate this response).
 */
static int
needs_validation(struct module_qstate* qstate, int ret_rc, 
        struct dns_msg* ret_msg)
{
        int rcode;

        /* If the CD bit is on in the original request, then you could think
         * that we don't bother to validate anything.
         * But this is signalled internally with the valrec flag.
         * User queries are validated with BIT_CD to make our cache clean
         * so that bogus messages get retried by the upstream also for
         * downstream validators that set BIT_CD.
         * For DNS64 bit_cd signals no dns64 processing, but we want to
         * provide validation there too */
        /*
        if(qstate->query_flags & BIT_CD) {
                verbose(VERB_ALGO, "not validating response due to CD bit");
                return 0;
        }
        */
        if(qstate->is_valrec) {
                verbose(VERB_ALGO, "not validating response, is valrec"
                        "(validation recursion lookup)");
                return 0;
        }

        if(ret_rc != LDNS_RCODE_NOERROR || !ret_msg)
                rcode = ret_rc;
        else    rcode = (int)FLAGS_GET_RCODE(ret_msg->rep->flags);

        if(rcode != LDNS_RCODE_NOERROR && rcode != LDNS_RCODE_NXDOMAIN) {
                if(verbosity >= VERB_ALGO) {
                        char rc[16];
                        rc[0]=0;
                        (void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
                        verbose(VERB_ALGO, "cannot validate non-answer, rcode %s", rc);
                }
                return 0;
        }

        /* cannot validate positive RRSIG response. (negatives can) */
        if(qstate->qinfo.qtype == LDNS_RR_TYPE_RRSIG &&
                rcode == LDNS_RCODE_NOERROR && ret_msg &&
                ret_msg->rep->an_numrrsets > 0) {
                verbose(VERB_ALGO, "cannot validate RRSIG, no sigs on sigs.");
                return 0;
        }
        return 1;
}

/**
 * Check to see if the response has already been validated.
 * @param ret_msg: return msg, can be NULL
 * @return true if the response has already been validated
 */
static int
already_validated(struct dns_msg* ret_msg)
{
        /* validate unchecked, and re-validate bogus messages */
        if (ret_msg && ret_msg->rep->security > sec_status_bogus)
        {
                verbose(VERB_ALGO, "response has already been validated: %s",
                        sec_status_to_string(ret_msg->rep->security));
                return 1;
        }
        return 0;
}

/**
 * Generate a request for DNS data.
 *
 * @param qstate: query state that is the parent.
 * @param id: module id.
 * @param name: what name to query for.
 * @param namelen: length of name.
 * @param qtype: query type.
 * @param qclass: query class.
 * @param flags: additional flags, such as the CD bit (BIT_CD), or 0.
 * @return false on alloc failure.
 */
static int
generate_request(struct module_qstate* qstate, int id, uint8_t* name, 
        size_t namelen, uint16_t qtype, uint16_t qclass, uint16_t flags)
{
        struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
        struct module_qstate* newq;
        struct query_info ask;
        int valrec;
        ask.qname = name;
        ask.qname_len = namelen;
        ask.qtype = qtype;
        ask.qclass = qclass;
        ask.local_alias = NULL;
        log_query_info(VERB_ALGO, "generate request", &ask);
        fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
        /* enable valrec flag to avoid recursion to the same validation
         * routine, this lookup is simply a lookup. DLVs need validation */
        if(qtype == LDNS_RR_TYPE_DLV)
                valrec = 0;
        else valrec = 1;
        if(!(*qstate->env->attach_sub)(qstate, &ask, 
                (uint16_t)(BIT_RD|flags), 0, valrec, &newq)){
                log_err("Could not generate request: out of memory");
                return 0;
        }
        /* newq; validator does not need state created for that
         * query, and its a 'normal' for iterator as well */
        if(newq) {
                /* add our blacklist to the query blacklist */
                sock_list_merge(&newq->blacklist, newq->region,
                        vq->chain_blacklist);
        }
        qstate->ext_state[id] = module_wait_subquery;
        return 1;
}

/**
 * Prime trust anchor for use.
 * Generate and dispatch a priming query for the given trust anchor.
 * The trust anchor can be DNSKEY or DS and does not have to be signed.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param id: module id.
 * @param toprime: what to prime.
 * @return false on a processing error.
 */
static int
prime_trust_anchor(struct module_qstate* qstate, struct val_qstate* vq,
        int id, struct trust_anchor* toprime)
{
        int ret = generate_request(qstate, id, toprime->name, toprime->namelen,
                LDNS_RR_TYPE_DNSKEY, toprime->dclass, BIT_CD);
        if(!ret) {
                log_err("Could not prime trust anchor: out of memory");
                return 0;
        }
        /* ignore newq; validator does not need state created for that
         * query, and its a 'normal' for iterator as well */
        vq->wait_prime_ta = 1; /* to elicit PRIME_RESP_STATE processing 
                from the validator inform_super() routine */
        /* store trust anchor name for later lookup when prime returns */
        vq->trust_anchor_name = regional_alloc_init(qstate->region,
                toprime->name, toprime->namelen);
        vq->trust_anchor_len = toprime->namelen;
        vq->trust_anchor_labs = toprime->namelabs;
        if(!vq->trust_anchor_name) {
                log_err("Could not prime trust anchor: out of memory");
                return 0;
        }
        return 1;
}

/**
 * Validate if the ANSWER and AUTHORITY sections contain valid rrsets.
 * They must be validly signed with the given key.
 * Tries to validate ADDITIONAL rrsets as well, but only to check them.
 * Allows unsigned CNAME after a DNAME that expands the DNAME.
 * 
 * Note that by the time this method is called, the process of finding the
 * trusted DNSKEY rrset that signs this response must already have been
 * completed.
 * 
 * @param qstate: query state.
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to validate.
 * @param key_entry: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 * @return false if any of the rrsets in the an or ns sections of the message 
 *      fail to verify. The message is then set to bogus.
 */
static int
validate_msg_signatures(struct module_qstate* qstate, struct module_env* env,
        struct val_env* ve, struct query_info* qchase,
        struct reply_info* chase_reply, struct key_entry_key* key_entry)
{
        uint8_t* sname;
        size_t i, slen;
        struct ub_packed_rrset_key* s;
        enum sec_status sec;
        int dname_seen = 0;
        char* reason = NULL;

        /* validate the ANSWER section */
        for(i=0; i<chase_reply->an_numrrsets; i++) {
                s = chase_reply->rrsets[i];
                /* Skip the CNAME following a (validated) DNAME.
                 * Because of the normalization routines in the iterator, 
                 * there will always be an unsigned CNAME following a DNAME 
                 * (unless qtype=DNAME). */
                if(dname_seen && ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
                        dname_seen = 0;
                        /* CNAME was synthesized by our own iterator */
                        /* since the DNAME verified, mark the CNAME as secure */
                        ((struct packed_rrset_data*)s->entry.data)->security =
                                sec_status_secure;
                        ((struct packed_rrset_data*)s->entry.data)->trust =
                                rrset_trust_validated;
                        continue;
                }

                /* Verify the answer rrset */
                sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason);
                /* If the (answer) rrset failed to validate, then this 
                 * message is BAD. */
                if(sec != sec_status_secure) {
                        log_nametypeclass(VERB_QUERY, "validator: response "
                                "has failed ANSWER rrset:", s->rk.dname,
                                ntohs(s->rk.type), ntohs(s->rk.rrset_class));
                        errinf(qstate, reason);
                        if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME)
                                errinf(qstate, "for CNAME");
                        else if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME)
                                errinf(qstate, "for DNAME");
                        errinf_origin(qstate, qstate->reply_origin);
                        chase_reply->security = sec_status_bogus;
                        return 0;
                }

                /* Notice a DNAME that should be followed by an unsigned 
                 * CNAME. */
                if(qchase->qtype != LDNS_RR_TYPE_DNAME && 
                        ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME) {
                        dname_seen = 1;
                }
        }

        /* validate the AUTHORITY section */
        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];
                sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason);
                /* If anything in the authority section fails to be secure, 
                 * we have a bad message. */
                if(sec != sec_status_secure) {
                        log_nametypeclass(VERB_QUERY, "validator: response "
                                "has failed AUTHORITY rrset:", s->rk.dname,
                                ntohs(s->rk.type), ntohs(s->rk.rrset_class));
                        errinf(qstate, reason);
                        errinf_origin(qstate, qstate->reply_origin);
                        errinf_rrset(qstate, s);
                        chase_reply->security = sec_status_bogus;
                        return 0;
                }
        }

        /* attempt to validate the ADDITIONAL section rrsets */
        if(!ve->clean_additional)
                return 1;
        for(i=chase_reply->an_numrrsets+chase_reply->ns_numrrsets; 
                i<chase_reply->rrset_count; i++) {
                s = chase_reply->rrsets[i];
                /* only validate rrs that have signatures with the key */
                /* leave others unchecked, those get removed later on too */
                val_find_rrset_signer(s, &sname, &slen);
                if(sname && query_dname_compare(sname, key_entry->name)==0)
                        (void)val_verify_rrset_entry(env, ve, s, key_entry,
                                &reason);
                /* the additional section can fail to be secure, 
                 * it is optional, check signature in case we need
                 * to clean the additional section later. */
        }

        return 1;
}

/**
 * Detect wrong truncated response (say from BIND 9.6.1 that is forwarding
 * and saw the NS record without signatures from a referral).
 * The positive response has a mangled authority section.
 * Remove that authority section and the additional section.
 * @param rep: reply
 * @return true if a wrongly truncated response.
 */
static int
detect_wrongly_truncated(struct reply_info* rep)
{
        size_t i;
        /* only NS in authority, and it is bogus */
        if(rep->ns_numrrsets != 1 || rep->an_numrrsets == 0)
                return 0;
        if(ntohs(rep->rrsets[ rep->an_numrrsets ]->rk.type) != LDNS_RR_TYPE_NS)
                return 0;
        if(((struct packed_rrset_data*)rep->rrsets[ rep->an_numrrsets ]
                ->entry.data)->security == sec_status_secure)
                return 0;
        /* answer section is present and secure */
        for(i=0; i<rep->an_numrrsets; i++) {
                if(((struct packed_rrset_data*)rep->rrsets[ i ]
                        ->entry.data)->security != sec_status_secure)
                        return 0;
        }
        verbose(VERB_ALGO, "truncating to minimal response");
        return 1;
}

/**
 * For messages that are not referrals, if the chase reply contains an
 * unsigned NS record in the authority section it could have been
 * inserted by a (BIND) forwarder that thinks the zone is insecure, and
 * that has an NS record without signatures in cache.  Remove the NS
 * record since the reply does not hinge on that record (in the authority
 * section), but do not remove it if it removes the last record from the
 * answer+authority sections.
 * @param chase_reply: the chased reply, we have a key for this contents,
 *      so we should have signatures for these rrsets and not having
 *      signatures means it will be bogus.
 * @param orig_reply: original reply, remove NS from there as well because
 *      we cannot mark the NS record as DNSSEC valid because it is not
 *      validated by signatures.
 */
static void
remove_spurious_authority(struct reply_info* chase_reply,
        struct reply_info* orig_reply)
{
        size_t i, found = 0;
        int remove = 0;
        /* if no answer and only 1 auth RRset, do not remove that one */
        if(chase_reply->an_numrrsets == 0 && chase_reply->ns_numrrsets == 1)
                return;
        /* search authority section for unsigned NS records */
        for(i = chase_reply->an_numrrsets;
                i < chase_reply->an_numrrsets+chase_reply->ns_numrrsets; i++) {
                struct packed_rrset_data* d = (struct packed_rrset_data*)
                        chase_reply->rrsets[i]->entry.data;
                if(ntohs(chase_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
                        && d->rrsig_count == 0) {
                        found = i;
                        remove = 1;
                        break;
                }
        }
        /* see if we found the entry */
        if(!remove) return;
        log_rrset_key(VERB_ALGO, "Removing spurious unsigned NS record "
                "(likely inserted by forwarder)", chase_reply->rrsets[found]);

        /* find rrset in orig_reply */
        for(i = orig_reply->an_numrrsets;
                i < orig_reply->an_numrrsets+orig_reply->ns_numrrsets; i++) {
                if(ntohs(orig_reply->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS
                        && query_dname_compare(orig_reply->rrsets[i]->rk.dname,
                                chase_reply->rrsets[found]->rk.dname) == 0) {
                        /* remove from orig_msg */
                        val_reply_remove_auth(orig_reply, i);
                        break;
                }
        }
        /* remove rrset from chase_reply */
        val_reply_remove_auth(chase_reply, found);
}

/**
 * Given a "positive" response -- a response that contains an answer to the
 * question, and no CNAME chain, validate this response. 
 *
 * The answer and authority RRsets must already be verified as secure.
 * 
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 */
static void
validate_positive_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey)
{
        uint8_t* wc = NULL;
        int wc_NSEC_ok = 0;
        int nsec3s_seen = 0;
        size_t i;
        struct ub_packed_rrset_key* s;

        /* validate the ANSWER section - this will be the answer itself */
        for(i=0; i<chase_reply->an_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* Check to see if the rrset is the result of a wildcard 
                 * expansion. If so, an additional check will need to be 
                 * made in the authority section. */
                if(!val_rrset_wildcard(s, &wc)) {
                        log_nametypeclass(VERB_QUERY, "Positive response has "
                                "inconsistent wildcard sigs:", s->rk.dname,
                                ntohs(s->rk.type), ntohs(s->rk.rrset_class));
                        chase_reply->security = sec_status_bogus;
                        return;
                }
        }

        /* validate the AUTHORITY section as well - this will generally be 
         * the NS rrset (which could be missing, no problem) */
        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* If this is a positive wildcard response, and we have a 
                 * (just verified) NSEC record, try to use it to 1) prove 
                 * that qname doesn't exist and 2) that the correct wildcard 
                 * was used. */
                if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
                                wc_NSEC_ok = 1;
                        }
                        /* if not, continue looking for proof */
                }

                /* Otherwise, if this is a positive wildcard response and 
                 * we have NSEC3 records */
                if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
                        nsec3s_seen = 1;
                }
        }

        /* If this was a positive wildcard response that we haven't already
         * proven, and we have NSEC3 records, try to prove it using the NSEC3
         * records. */
        if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
                enum sec_status sec = nsec3_prove_wildcard(env, ve, 
                        chase_reply->rrsets+chase_reply->an_numrrsets,
                        chase_reply->ns_numrrsets, qchase, kkey, wc);
                if(sec == sec_status_insecure) {
                        verbose(VERB_ALGO, "Positive wildcard response is "
                                "insecure");
                        chase_reply->security = sec_status_insecure;
                        return;
                } else if(sec == sec_status_secure)
                        wc_NSEC_ok = 1;
        }

        /* If after all this, we still haven't proven the positive wildcard
         * response, fail. */
        if(wc != NULL && !wc_NSEC_ok) {
                verbose(VERB_QUERY, "positive response was wildcard "
                        "expansion and did not prove original data "
                        "did not exist");
                chase_reply->security = sec_status_bogus;
                return;
        }

        verbose(VERB_ALGO, "Successfully validated positive response");
        chase_reply->security = sec_status_secure;
}

/** 
 * Validate a NOERROR/NODATA signed response -- a response that has a
 * NOERROR Rcode but no ANSWER section RRsets. This consists of making 
 * certain that the authority section NSEC/NSEC3s proves that the qname 
 * does exist and the qtype doesn't.
 *
 * The answer and authority RRsets must already be verified as secure.
 *
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 */
static void
validate_nodata_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey)
{
        /* Since we are here, there must be nothing in the ANSWER section to
         * validate. */
        /* (Note: CNAME/DNAME responses will not directly get here --
         * instead, they are chased down into individual CNAME validations,
         * and at the end of the cname chain a POSITIVE, or CNAME_NOANSWER 
         * validation.) */
        
        /* validate the AUTHORITY section */
        int has_valid_nsec = 0; /* If true, then the NODATA has been proven.*/
        uint8_t* ce = NULL; /* for wildcard nodata responses. This is the 
                                proven closest encloser. */
        uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
        int nsec3s_seen = 0; /* nsec3s seen */
        struct ub_packed_rrset_key* s; 
        size_t i;

        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];
                /* If we encounter an NSEC record, try to use it to prove 
                 * NODATA.
                 * This needs to handle the ENT NODATA case. */
                if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(nsec_proves_nodata(s, qchase, &wc)) {
                                has_valid_nsec = 1;
                                /* sets wc-encloser if wildcard applicable */
                        } 
                        if(val_nsec_proves_name_error(s, qchase->qname)) {
                                ce = nsec_closest_encloser(qchase->qname, s);
                        }
                        if(val_nsec_proves_insecuredelegation(s, qchase)) {
                                verbose(VERB_ALGO, "delegation is insecure");
                                chase_reply->security = sec_status_insecure;
                                return;
                        }
                } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
                        nsec3s_seen = 1;
                }
        }

        /* check to see if we have a wildcard NODATA proof. */

        /* The wildcard NODATA is 1 NSEC proving that qname does not exist 
         * (and also proving what the closest encloser is), and 1 NSEC 
         * showing the matching wildcard, which must be *.closest_encloser. */
        if(wc && !ce)
                has_valid_nsec = 0;
        else if(wc && ce) {
                if(query_dname_compare(wc, ce) != 0) {
                        has_valid_nsec = 0;
                }
        }
        
        if(!has_valid_nsec && nsec3s_seen) {
                enum sec_status sec = nsec3_prove_nodata(env, ve, 
                        chase_reply->rrsets+chase_reply->an_numrrsets,
                        chase_reply->ns_numrrsets, qchase, kkey);
                if(sec == sec_status_insecure) {
                        verbose(VERB_ALGO, "NODATA response is insecure");
                        chase_reply->security = sec_status_insecure;
                        return;
                } else if(sec == sec_status_secure)
                        has_valid_nsec = 1;
        }

        if(!has_valid_nsec) {
                verbose(VERB_QUERY, "NODATA response failed to prove NODATA "
                        "status with NSEC/NSEC3");
                if(verbosity >= VERB_ALGO)
                        log_dns_msg("Failed NODATA", qchase, chase_reply);
                chase_reply->security = sec_status_bogus;
                return;
        }

        verbose(VERB_ALGO, "successfully validated NODATA response.");
        chase_reply->security = sec_status_secure;
}

/** 
 * Validate a NAMEERROR signed response -- a response that has a NXDOMAIN
 * Rcode. 
 * This consists of making certain that the authority section NSEC proves 
 * that the qname doesn't exist and the covering wildcard also doesn't exist..
 * 
 * The answer and authority RRsets must have already been verified as secure.
 *
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 * @param rcode: adjusted RCODE, in case of RCODE/proof mismatch leniency.
 */
static void
validate_nameerror_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey, int* rcode)
{
        int has_valid_nsec = 0;
        int has_valid_wnsec = 0;
        int nsec3s_seen = 0;
        struct ub_packed_rrset_key* s; 
        size_t i;

        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];
                if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(val_nsec_proves_name_error(s, qchase->qname))
                                has_valid_nsec = 1;
                        if(val_nsec_proves_no_wc(s, qchase->qname, 
                                qchase->qname_len))
                                has_valid_wnsec = 1;
                        if(val_nsec_proves_insecuredelegation(s, qchase)) {
                                verbose(VERB_ALGO, "delegation is insecure");
                                chase_reply->security = sec_status_insecure;
                                return;
                        }
                } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3)
                        nsec3s_seen = 1;
        }

        if((!has_valid_nsec || !has_valid_wnsec) && nsec3s_seen) {
                /* use NSEC3 proof, both answer and auth rrsets, in case
                 * NSEC3s end up in the answer (due to qtype=NSEC3 or so) */
                chase_reply->security = nsec3_prove_nameerror(env, ve,
                        chase_reply->rrsets, chase_reply->an_numrrsets+
                        chase_reply->ns_numrrsets, qchase, kkey);
                if(chase_reply->security != sec_status_secure) {
                        verbose(VERB_QUERY, "NameError response failed nsec, "
                                "nsec3 proof was %s", sec_status_to_string(
                                chase_reply->security));
                        return;
                }
                has_valid_nsec = 1;
                has_valid_wnsec = 1;
        }

        /* If the message fails to prove either condition, it is bogus. */
        if(!has_valid_nsec) {
                verbose(VERB_QUERY, "NameError response has failed to prove: "
                          "qname does not exist");
                chase_reply->security = sec_status_bogus;
                /* Be lenient with RCODE in NSEC NameError responses */
                validate_nodata_response(env, ve, qchase, chase_reply, kkey);
                if (chase_reply->security == sec_status_secure)
                        *rcode = LDNS_RCODE_NOERROR;
                return;
        }

        if(!has_valid_wnsec) {
                verbose(VERB_QUERY, "NameError response has failed to prove: "
                          "covering wildcard does not exist");
                chase_reply->security = sec_status_bogus;
                /* Be lenient with RCODE in NSEC NameError responses */
                validate_nodata_response(env, ve, qchase, chase_reply, kkey);
                if (chase_reply->security == sec_status_secure)
                        *rcode = LDNS_RCODE_NOERROR;
                return;
        }

        /* Otherwise, we consider the message secure. */
        verbose(VERB_ALGO, "successfully validated NAME ERROR response.");
        chase_reply->security = sec_status_secure;
}

/** 
 * Given a referral response, validate rrsets and take least trusted rrset
 * as the current validation status.
 * 
 * Note that by the time this method is called, the process of finding the
 * trusted DNSKEY rrset that signs this response must already have been
 * completed.
 * 
 * @param chase_reply: answer to validate.
 */
static void
validate_referral_response(struct reply_info* chase_reply)
{
        size_t i;
        enum sec_status s;
        /* message security equals lowest rrset security */
        chase_reply->security = sec_status_secure;
        for(i=0; i<chase_reply->rrset_count; i++) {
                s = ((struct packed_rrset_data*)chase_reply->rrsets[i]
                        ->entry.data)->security;
                if(s < chase_reply->security)
                        chase_reply->security = s;
        }
        verbose(VERB_ALGO, "validated part of referral response as %s",
                sec_status_to_string(chase_reply->security));
}

/** 
 * Given an "ANY" response -- a response that contains an answer to a
 * qtype==ANY question, with answers. This does no checking that all 
 * types are present.
 * 
 * NOTE: it may be possible to get parent-side delegation point records
 * here, which won't all be signed. Right now, this routine relies on the
 * upstream iterative resolver to not return these responses -- instead
 * treating them as referrals.
 * 
 * NOTE: RFC 4035 is silent on this issue, so this may change upon
 * clarification. Clarification draft -05 says to not check all types are
 * present.
 * 
 * Note that by the time this method is called, the process of finding the
 * trusted DNSKEY rrset that signs this response must already have been
 * completed.
 * 
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 */
static void
validate_any_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey)
{
        /* all answer and auth rrsets already verified */
        /* but check if a wildcard response is given, then check NSEC/NSEC3
         * for qname denial to see if wildcard is applicable */
        uint8_t* wc = NULL;
        int wc_NSEC_ok = 0;
        int nsec3s_seen = 0;
        size_t i;
        struct ub_packed_rrset_key* s;

        if(qchase->qtype != LDNS_RR_TYPE_ANY) {
                log_err("internal error: ANY validation called for non-ANY");
                chase_reply->security = sec_status_bogus;
                return;
        }

        /* validate the ANSWER section - this will be the answer itself */
        for(i=0; i<chase_reply->an_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* Check to see if the rrset is the result of a wildcard 
                 * expansion. If so, an additional check will need to be 
                 * made in the authority section. */
                if(!val_rrset_wildcard(s, &wc)) {
                        log_nametypeclass(VERB_QUERY, "Positive ANY response"
                                " has inconsistent wildcard sigs:", 
                                s->rk.dname, ntohs(s->rk.type), 
                                ntohs(s->rk.rrset_class));
                        chase_reply->security = sec_status_bogus;
                        return;
                }
        }

        /* if it was a wildcard, check for NSEC/NSEC3s in both answer
         * and authority sections (NSEC may be moved to the ANSWER section) */
        if(wc != NULL)
          for(i=0; i<chase_reply->an_numrrsets+chase_reply->ns_numrrsets; 
                i++) {
                s = chase_reply->rrsets[i];

                /* If this is a positive wildcard response, and we have a 
                 * (just verified) NSEC record, try to use it to 1) prove 
                 * that qname doesn't exist and 2) that the correct wildcard 
                 * was used. */
                if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
                                wc_NSEC_ok = 1;
                        }
                        /* if not, continue looking for proof */
                }

                /* Otherwise, if this is a positive wildcard response and 
                 * we have NSEC3 records */
                if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
                        nsec3s_seen = 1;
                }
        }

        /* If this was a positive wildcard response that we haven't already
         * proven, and we have NSEC3 records, try to prove it using the NSEC3
         * records. */
        if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
                /* look both in answer and auth section for NSEC3s */
                enum sec_status sec = nsec3_prove_wildcard(env, ve, 
                        chase_reply->rrsets,
                        chase_reply->an_numrrsets+chase_reply->ns_numrrsets, 
                        qchase, kkey, wc);
                if(sec == sec_status_insecure) {
                        verbose(VERB_ALGO, "Positive ANY wildcard response is "
                                "insecure");
                        chase_reply->security = sec_status_insecure;
                        return;
                } else if(sec == sec_status_secure)
                        wc_NSEC_ok = 1;
        }

        /* If after all this, we still haven't proven the positive wildcard
         * response, fail. */
        if(wc != NULL && !wc_NSEC_ok) {
                verbose(VERB_QUERY, "positive ANY response was wildcard "
                        "expansion and did not prove original data "
                        "did not exist");
                chase_reply->security = sec_status_bogus;
                return;
        }

        verbose(VERB_ALGO, "Successfully validated positive ANY response");
        chase_reply->security = sec_status_secure;
}

/**
 * Validate CNAME response, or DNAME+CNAME.
 * This is just like a positive proof, except that this is about a 
 * DNAME+CNAME. Possible wildcard proof.
 * Difference with positive proof is that this routine refuses 
 * wildcarded DNAMEs.
 * 
 * The answer and authority rrsets must already be verified as secure.
 * 
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 */
static void
validate_cname_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey)
{
        uint8_t* wc = NULL;
        int wc_NSEC_ok = 0;
        int nsec3s_seen = 0;
        size_t i;
        struct ub_packed_rrset_key* s;

        /* validate the ANSWER section - this will be the CNAME (+DNAME) */
        for(i=0; i<chase_reply->an_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* Check to see if the rrset is the result of a wildcard 
                 * expansion. If so, an additional check will need to be 
                 * made in the authority section. */
                if(!val_rrset_wildcard(s, &wc)) {
                        log_nametypeclass(VERB_QUERY, "Cname response has "
                                "inconsistent wildcard sigs:", s->rk.dname,
                                ntohs(s->rk.type), ntohs(s->rk.rrset_class));
                        chase_reply->security = sec_status_bogus;
                        return;
                }
                
                /* Refuse wildcarded DNAMEs rfc 4597. 
                 * Do not follow a wildcarded DNAME because 
                 * its synthesized CNAME expansion is underdefined */
                if(qchase->qtype != LDNS_RR_TYPE_DNAME && 
                        ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME && wc) {
                        log_nametypeclass(VERB_QUERY, "cannot validate a "
                                "wildcarded DNAME:", s->rk.dname, 
                                ntohs(s->rk.type), ntohs(s->rk.rrset_class));
                        chase_reply->security = sec_status_bogus;
                        return;
                }

                /* If we have found a CNAME, stop looking for one.
                 * The iterator has placed the CNAME chain in correct
                 * order. */
                if (ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
                        break;
                }
        }

        /* AUTHORITY section */
        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* If this is a positive wildcard response, and we have a 
                 * (just verified) NSEC record, try to use it to 1) prove 
                 * that qname doesn't exist and 2) that the correct wildcard 
                 * was used. */
                if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
                                wc_NSEC_ok = 1;
                        }
                        /* if not, continue looking for proof */
                }

                /* Otherwise, if this is a positive wildcard response and 
                 * we have NSEC3 records */
                if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
                        nsec3s_seen = 1;
                }
        }

        /* If this was a positive wildcard response that we haven't already
         * proven, and we have NSEC3 records, try to prove it using the NSEC3
         * records. */
        if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
                enum sec_status sec = nsec3_prove_wildcard(env, ve, 
                        chase_reply->rrsets+chase_reply->an_numrrsets,
                        chase_reply->ns_numrrsets, qchase, kkey, wc);
                if(sec == sec_status_insecure) {
                        verbose(VERB_ALGO, "wildcard CNAME response is "
                                "insecure");
                        chase_reply->security = sec_status_insecure;
                        return;
                } else if(sec == sec_status_secure)
                        wc_NSEC_ok = 1;
        }

        /* If after all this, we still haven't proven the positive wildcard
         * response, fail. */
        if(wc != NULL && !wc_NSEC_ok) {
                verbose(VERB_QUERY, "CNAME response was wildcard "
                        "expansion and did not prove original data "
                        "did not exist");
                chase_reply->security = sec_status_bogus;
                return;
        }

        verbose(VERB_ALGO, "Successfully validated CNAME response");
        chase_reply->security = sec_status_secure;
}

/**
 * Validate CNAME NOANSWER response, no more data after a CNAME chain.
 * This can be a NODATA or a NAME ERROR case, but not both at the same time.
 * We don't know because the rcode has been set to NOERROR by the CNAME.
 * 
 * The answer and authority rrsets must already be verified as secure.
 * 
 * @param env: module env for verify.
 * @param ve: validator env for verify.
 * @param qchase: query that was made.
 * @param chase_reply: answer to that query to validate.
 * @param kkey: the key entry, which is trusted, and which matches
 *      the signer of the answer. The key entry isgood().
 */
static void
validate_cname_noanswer_response(struct module_env* env, struct val_env* ve,
        struct query_info* qchase, struct reply_info* chase_reply,
        struct key_entry_key* kkey)
{
        int nodata_valid_nsec = 0; /* If true, then NODATA has been proven.*/
        uint8_t* ce = NULL; /* for wildcard nodata responses. This is the 
                                proven closest encloser. */
        uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
        int nxdomain_valid_nsec = 0; /* if true, namerror has been proven */
        int nxdomain_valid_wnsec = 0;
        int nsec3s_seen = 0; /* nsec3s seen */
        struct ub_packed_rrset_key* s; 
        size_t i;

        /* the AUTHORITY section */
        for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
                chase_reply->ns_numrrsets; i++) {
                s = chase_reply->rrsets[i];

                /* If we encounter an NSEC record, try to use it to prove 
                 * NODATA. This needs to handle the ENT NODATA case. 
                 * Also try to prove NAMEERROR, and absence of a wildcard */
                if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
                        if(nsec_proves_nodata(s, qchase, &wc)) {
                                nodata_valid_nsec = 1;
                                /* set wc encloser if wildcard applicable */
                        } 
                        if(val_nsec_proves_name_error(s, qchase->qname)) {
                                ce = nsec_closest_encloser(qchase->qname, s);
                                nxdomain_valid_nsec = 1;
                        }
                        if(val_nsec_proves_no_wc(s, qchase->qname, 
                                qchase->qname_len))
                                nxdomain_valid_wnsec = 1;
                        if(val_nsec_proves_insecuredelegation(s, qchase)) {
                                verbose(VERB_ALGO, "delegation is insecure");
                                chase_reply->security = sec_status_insecure;
                                return;
                        }
                } else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
                        nsec3s_seen = 1;
                }
        }

        /* check to see if we have a wildcard NODATA proof. */

        /* The wildcard NODATA is 1 NSEC proving that qname does not exists 
         * (and also proving what the closest encloser is), and 1 NSEC 
         * showing the matching wildcard, which must be *.closest_encloser. */
        if(wc && !ce)
                nodata_valid_nsec = 0;
        else if(wc && ce) {
                if(query_dname_compare(wc, ce) != 0) {
                        nodata_valid_nsec = 0;
                }
        }
        if(nxdomain_valid_nsec && !nxdomain_valid_wnsec) {
                /* name error is missing wildcard denial proof */
                nxdomain_valid_nsec = 0;
        }
        
        if(nodata_valid_nsec && nxdomain_valid_nsec) {
                verbose(VERB_QUERY, "CNAMEchain to noanswer proves that name "
                        "exists and not exists, bogus");
                chase_reply->security = sec_status_bogus;
                return;
        }
        if(!nodata_valid_nsec && !nxdomain_valid_nsec && nsec3s_seen) {
                int nodata;
                enum sec_status sec = nsec3_prove_nxornodata(env, ve, 
                        chase_reply->rrsets+chase_reply->an_numrrsets,
                        chase_reply->ns_numrrsets, qchase, kkey, &nodata);
                if(sec == sec_status_insecure) {
                        verbose(VERB_ALGO, "CNAMEchain to noanswer response "
                                "is insecure");
                        chase_reply->security = sec_status_insecure;
                        return;
                } else if(sec == sec_status_secure) {
                        if(nodata)
                                nodata_valid_nsec = 1;
                        else    nxdomain_valid_nsec = 1;
                }
        }

        if(!nodata_valid_nsec && !nxdomain_valid_nsec) {
                verbose(VERB_QUERY, "CNAMEchain to noanswer response failed "
                        "to prove status with NSEC/NSEC3");
                if(verbosity >= VERB_ALGO)
                        log_dns_msg("Failed CNAMEnoanswer", qchase, chase_reply);
                chase_reply->security = sec_status_bogus;
                return;
        }

        if(nodata_valid_nsec)
                verbose(VERB_ALGO, "successfully validated CNAME chain to a "
                        "NODATA response.");
        else    verbose(VERB_ALGO, "successfully validated CNAME chain to a "
                        "NAMEERROR response.");
        chase_reply->security = sec_status_secure;
}

/** 
 * Process init state for validator.
 * Process the INIT state. First tier responses start in the INIT state.
 * This is where they are vetted for validation suitability, and the initial
 * key search is done.
 * 
 * Currently, events the come through this routine will be either promoted
 * to FINISHED/CNAME_RESP (no validation needed), FINDKEY (next step to
 * validation), or will be (temporarily) retired and a new priming request
 * event will be generated.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 * @return true if the event should be processed further on return, false if
 *         not.
 */
static int
processInit(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        uint8_t* lookup_name;
        size_t lookup_len;
        struct trust_anchor* anchor;
        enum val_classification subtype = val_classify_response(
                qstate->query_flags, &qstate->qinfo, &vq->qchase, 
                vq->orig_msg->rep, vq->rrset_skip);
        if(vq->restart_count > VAL_MAX_RESTART_COUNT) {
                verbose(VERB_ALGO, "restart count exceeded");
                return val_error(qstate, id);
        }
        verbose(VERB_ALGO, "validator classification %s", 
                val_classification_to_string(subtype));
        if(subtype == VAL_CLASS_REFERRAL && 
                vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
                /* referral uses the rrset name as qchase, to find keys for
                 * that rrset */
                vq->qchase.qname = vq->orig_msg->rep->
                        rrsets[vq->rrset_skip]->rk.dname;
                vq->qchase.qname_len = vq->orig_msg->rep->
                        rrsets[vq->rrset_skip]->rk.dname_len;
                vq->qchase.qtype = ntohs(vq->orig_msg->rep->
                        rrsets[vq->rrset_skip]->rk.type);
                vq->qchase.qclass = ntohs(vq->orig_msg->rep->
                        rrsets[vq->rrset_skip]->rk.rrset_class);
        }
        lookup_name = vq->qchase.qname;
        lookup_len = vq->qchase.qname_len;
        /* for type DS look at the parent side for keys/trustanchor */
        /* also for NSEC not at apex */
        if(vq->qchase.qtype == LDNS_RR_TYPE_DS ||
                (vq->qchase.qtype == LDNS_RR_TYPE_NSEC && 
                 vq->orig_msg->rep->rrset_count > vq->rrset_skip &&
                 ntohs(vq->orig_msg->rep->rrsets[vq->rrset_skip]->rk.type) ==
                 LDNS_RR_TYPE_NSEC &&
                 !(vq->orig_msg->rep->rrsets[vq->rrset_skip]->
                 rk.flags&PACKED_RRSET_NSEC_AT_APEX))) {
                dname_remove_label(&lookup_name, &lookup_len);
        }

        val_mark_indeterminate(vq->chase_reply, qstate->env->anchors, 
                qstate->env->rrset_cache, qstate->env);
        vq->key_entry = NULL;
        vq->empty_DS_name = NULL;
        vq->ds_rrset = 0;
        anchor = anchors_lookup(qstate->env->anchors, 
                lookup_name, lookup_len, vq->qchase.qclass);

        /* Determine the signer/lookup name */
        val_find_signer(subtype, &vq->qchase, vq->orig_msg->rep, 
                vq->rrset_skip, &vq->signer_name, &vq->signer_len);
        if(vq->signer_name != NULL &&
                !dname_subdomain_c(lookup_name, vq->signer_name)) {
                log_nametypeclass(VERB_ALGO, "this signer name is not a parent "
                        "of lookupname, omitted", vq->signer_name, 0, 0);
                vq->signer_name = NULL;
        }
        if(vq->signer_name == NULL) {
                log_nametypeclass(VERB_ALGO, "no signer, using", lookup_name,
                        0, 0);
        } else {
                lookup_name = vq->signer_name;
                lookup_len = vq->signer_len;
                log_nametypeclass(VERB_ALGO, "signer is", lookup_name, 0, 0);
        }

        /* for NXDOMAIN it could be signed by a parent of the trust anchor */
        if(subtype == VAL_CLASS_NAMEERROR && vq->signer_name &&
                anchor && dname_strict_subdomain_c(anchor->name, lookup_name)){
                lock_basic_unlock(&anchor->lock);
                anchor = anchors_lookup(qstate->env->anchors, 
                        lookup_name, lookup_len, vq->qchase.qclass);
                if(!anchor) { /* unsigned parent denies anchor*/
                        verbose(VERB_QUERY, "unsigned parent zone denies"
                                " trust anchor, indeterminate");
                        vq->chase_reply->security = sec_status_indeterminate;
                        vq->state = VAL_FINISHED_STATE;
                        return 1;
                }
                verbose(VERB_ALGO, "trust anchor NXDOMAIN by signed parent");
        } else if(subtype == VAL_CLASS_POSITIVE &&
                qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
                query_dname_compare(lookup_name, qstate->qinfo.qname) == 0) {
                /* is a DNSKEY so lookup a bit higher since we want to
                 * get it from a parent or from trustanchor */
                dname_remove_label(&lookup_name, &lookup_len);
        }

        if(vq->rrset_skip > 0 || subtype == VAL_CLASS_CNAME ||
                subtype == VAL_CLASS_REFERRAL) {
                /* extract this part of orig_msg into chase_reply for
                 * the eventual VALIDATE stage */
                val_fill_reply(vq->chase_reply, vq->orig_msg->rep, 
                        vq->rrset_skip, lookup_name, lookup_len, 
                        vq->signer_name);
                if(verbosity >= VERB_ALGO)
                        log_dns_msg("chased extract", &vq->qchase, 
                                vq->chase_reply);
        }

        vq->key_entry = key_cache_obtain(ve->kcache, lookup_name, lookup_len,
                vq->qchase.qclass, qstate->region, *qstate->env->now);

        /* there is no key(from DLV) and no trust anchor */
        if(vq->key_entry == NULL && anchor == NULL) {
                /*response isn't under a trust anchor, so we cannot validate.*/
                vq->chase_reply->security = sec_status_indeterminate;
                /* go to finished state to cache this result */
                vq->state = VAL_FINISHED_STATE;
                return 1;
        }
        /* if not key, or if keyentry is *above* the trustanchor, i.e.
         * the keyentry is based on another (higher) trustanchor */
        else if(vq->key_entry == NULL || (anchor &&
                dname_strict_subdomain_c(anchor->name, vq->key_entry->name))) {
                /* trust anchor is an 'unsigned' trust anchor */
                if(anchor && anchor->numDS == 0 && anchor->numDNSKEY == 0) {
                        vq->chase_reply->security = sec_status_insecure;
                        val_mark_insecure(vq->chase_reply, anchor->name, 
                                qstate->env->rrset_cache, qstate->env);
                        lock_basic_unlock(&anchor->lock);
                        vq->dlv_checked=1; /* skip DLV check */
                        /* go to finished state to cache this result */
                        vq->state = VAL_FINISHED_STATE;
                        return 1;
                }
                /* fire off a trust anchor priming query. */
                verbose(VERB_DETAIL, "prime trust anchor");
                if(!prime_trust_anchor(qstate, vq, id, anchor)) {
                        lock_basic_unlock(&anchor->lock);
                        return val_error(qstate, id);
                }
                lock_basic_unlock(&anchor->lock);
                /* and otherwise, don't continue processing this event.
                 * (it will be reactivated when the priming query returns). */
                vq->state = VAL_FINDKEY_STATE;
                return 0;
        }
        if(anchor) {
                lock_basic_unlock(&anchor->lock);
        }

        if(key_entry_isnull(vq->key_entry)) {
                /* response is under a null key, so we cannot validate
                 * However, we do set the status to INSECURE, since it is 
                 * essentially proven insecure. */
                vq->chase_reply->security = sec_status_insecure;
                val_mark_insecure(vq->chase_reply, vq->key_entry->name, 
                        qstate->env->rrset_cache, qstate->env);
                /* go to finished state to cache this result */
                vq->state = VAL_FINISHED_STATE;
                return 1;
        } else if(key_entry_isbad(vq->key_entry)) {
                /* key is bad, chain is bad, reply is bogus */
                errinf_dname(qstate, "key for validation", vq->key_entry->name);
                errinf(qstate, "is marked as invalid");
                if(key_entry_get_reason(vq->key_entry)) {
                        errinf(qstate, "because of a previous");
                        errinf(qstate, key_entry_get_reason(vq->key_entry));
                }
                /* no retries, stop bothering the authority until timeout */
                vq->restart_count = VAL_MAX_RESTART_COUNT;
                vq->chase_reply->security = sec_status_bogus;
                vq->state = VAL_FINISHED_STATE;
                return 1;
        }

        /* otherwise, we have our "closest" cached key -- continue 
         * processing in the next state. */
        vq->state = VAL_FINDKEY_STATE;
        return 1;
}

/**
 * Process the FINDKEY state. Generally this just calculates the next name
 * to query and either issues a DS or a DNSKEY query. It will check to see
 * if the correct key has already been reached, in which case it will
 * advance the event to the next state.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param id: module id.
 * @return true if the event should be processed further on return, false if
 *         not.
 */
static int
processFindKey(struct module_qstate* qstate, struct val_qstate* vq, int id)
{
        uint8_t* target_key_name, *current_key_name;
        size_t target_key_len;
        int strip_lab;

        log_query_info(VERB_ALGO, "validator: FindKey", &vq->qchase);
        /* We know that state.key_entry is not 0 or bad key -- if it were,
         * then previous processing should have directed this event to 
         * a different state. 
         * It could be an isnull key, which signals that a DLV was just
         * done and the DNSKEY after the DLV failed with dnssec-retry state
         * and the DNSKEY has to be performed again. */
        log_assert(vq->key_entry && !key_entry_isbad(vq->key_entry));
        if(key_entry_isnull(vq->key_entry)) {
                if(!generate_request(qstate, id, vq->ds_rrset->rk.dname, 
                        vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY, 
                        vq->qchase.qclass, BIT_CD)) {
                        log_err("mem error generating DNSKEY request");
                        return val_error(qstate, id);
                }
                return 0;
        }

        target_key_name = vq->signer_name;
        target_key_len = vq->signer_len;
        if(!target_key_name) {
                target_key_name = vq->qchase.qname;
                target_key_len = vq->qchase.qname_len;
        }

        current_key_name = vq->key_entry->name;

        /* If our current key entry matches our target, then we are done. */
        if(query_dname_compare(target_key_name, current_key_name) == 0) {
                vq->state = VAL_VALIDATE_STATE;
                return 1;
        }

        if(vq->empty_DS_name) {
                /* if the last empty nonterminal/emptyDS name we detected is
                 * below the current key, use that name to make progress
                 * along the chain of trust */
                if(query_dname_compare(target_key_name, 
                        vq->empty_DS_name) == 0) {
                        /* do not query for empty_DS_name again */
                        verbose(VERB_ALGO, "Cannot retrieve DS for signature");
                        errinf(qstate, "no signatures");
                        errinf_origin(qstate, qstate->reply_origin);
                        vq->chase_reply->security = sec_status_bogus;
                        vq->state = VAL_FINISHED_STATE;
                        return 1;
                }
                current_key_name = vq->empty_DS_name;
        }

        log_nametypeclass(VERB_ALGO, "current keyname", current_key_name,
                LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
        log_nametypeclass(VERB_ALGO, "target keyname", target_key_name,
                LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
        /* assert we are walking down the DNS tree */
        if(!dname_subdomain_c(target_key_name, current_key_name)) {
                verbose(VERB_ALGO, "bad signer name");
                vq->chase_reply->security = sec_status_bogus;
                vq->state = VAL_FINISHED_STATE;
                return 1;
        }
        /* so this value is >= -1 */
        strip_lab = dname_count_labels(target_key_name) - 
                dname_count_labels(current_key_name) - 1;
        log_assert(strip_lab >= -1);
        verbose(VERB_ALGO, "striplab %d", strip_lab);
        if(strip_lab > 0) {
                dname_remove_labels(&target_key_name, &target_key_len, 
                        strip_lab);
        }
        log_nametypeclass(VERB_ALGO, "next keyname", target_key_name,
                LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);

        /* The next step is either to query for the next DS, or to query 
         * for the next DNSKEY. */
        if(vq->ds_rrset)
                log_nametypeclass(VERB_ALGO, "DS RRset", vq->ds_rrset->rk.dname, LDNS_RR_TYPE_DS, LDNS_RR_CLASS_IN);
        else verbose(VERB_ALGO, "No DS RRset");

        if(vq->ds_rrset && query_dname_compare(vq->ds_rrset->rk.dname,
                vq->key_entry->name) != 0) {
                if(!generate_request(qstate, id, vq->ds_rrset->rk.dname, 
                        vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY, 
                        vq->qchase.qclass, BIT_CD)) {
                        log_err("mem error generating DNSKEY request");
                        return val_error(qstate, id);
                }
                return 0;
        }

        if(!vq->ds_rrset || query_dname_compare(vq->ds_rrset->rk.dname,
                target_key_name) != 0) {
                /* check if there is a cache entry : pick up an NSEC if
                 * there is no DS, check if that NSEC has DS-bit unset, and
                 * thus can disprove the secure delegation we seek.
                 * We can then use that NSEC even in the absence of a SOA
                 * record that would be required by the iterator to supply
                 * a completely protocol-correct response. 
                 * Uses negative cache for NSEC3 lookup of DS responses. */
                /* only if cache not blacklisted, of course */
                struct dns_msg* msg;
                if(!qstate->blacklist && !vq->chain_blacklist &&
                        (msg=val_find_DS(qstate->env, target_key_name, 
                        target_key_len, vq->qchase.qclass, qstate->region,
                        vq->key_entry->name)) ) {
                        verbose(VERB_ALGO, "Process cached DS response");
                        process_ds_response(qstate, vq, id, LDNS_RCODE_NOERROR,
                                msg, &msg->qinfo, NULL);
                        return 1; /* continue processing ds-response results */
                }
                if(!generate_request(qstate, id, target_key_name, 
                        target_key_len, LDNS_RR_TYPE_DS, vq->qchase.qclass,
                        BIT_CD)) {
                        log_err("mem error generating DS request");
                        return val_error(qstate, id);
                }
                return 0;
        }

        /* Otherwise, it is time to query for the DNSKEY */
        if(!generate_request(qstate, id, vq->ds_rrset->rk.dname, 
                vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY, 
                vq->qchase.qclass, BIT_CD)) {
                log_err("mem error generating DNSKEY request");
                return val_error(qstate, id);
        }

        return 0;
}

/**
 * Process the VALIDATE stage, the init and findkey stages are finished,
 * and the right keys are available to validate the response.
 * Or, there are no keys available, in order to invalidate the response.
 *
 * After validation, the status is recorded in the message and rrsets,
 * and finished state is started.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 * @return true if the event should be processed further on return, false if
 *         not.
 */
static int
processValidate(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        enum val_classification subtype;
        int rcode;

        if(!vq->key_entry) {
                verbose(VERB_ALGO, "validate: no key entry, failed");
                return val_error(qstate, id);
        }

        /* This is the default next state. */
        vq->state = VAL_FINISHED_STATE;

        /* Unsigned responses must be underneath a "null" key entry.*/
        if(key_entry_isnull(vq->key_entry)) {
                verbose(VERB_DETAIL, "Verified that %sresponse is INSECURE",
                        vq->signer_name?"":"unsigned ");
                vq->chase_reply->security = sec_status_insecure;
                val_mark_insecure(vq->chase_reply, vq->key_entry->name, 
                        qstate->env->rrset_cache, qstate->env);
                key_cache_insert(ve->kcache, vq->key_entry, qstate);
                return 1;
        }

        if(key_entry_isbad(vq->key_entry)) {
                log_nametypeclass(VERB_DETAIL, "Could not establish a chain "
                        "of trust to keys for", vq->key_entry->name,
                        LDNS_RR_TYPE_DNSKEY, vq->key_entry->key_class);
                vq->chase_reply->security = sec_status_bogus;
                errinf(qstate, "while building chain of trust");
                if(vq->restart_count >= VAL_MAX_RESTART_COUNT)
                        key_cache_insert(ve->kcache, vq->key_entry, qstate);
                return 1;
        }

        /* signerName being null is the indicator that this response was 
         * unsigned */
        if(vq->signer_name == NULL) {
                log_query_info(VERB_ALGO, "processValidate: state has no "
                        "signer name", &vq->qchase);
                verbose(VERB_DETAIL, "Could not establish validation of "
                          "INSECURE status of unsigned response.");
                errinf(qstate, "no signatures");
                errinf_origin(qstate, qstate->reply_origin);
                vq->chase_reply->security = sec_status_bogus;
                return 1;
        }
        subtype = val_classify_response(qstate->query_flags, &qstate->qinfo,
                &vq->qchase, vq->orig_msg->rep, vq->rrset_skip);
        if(subtype != VAL_CLASS_REFERRAL)
                remove_spurious_authority(vq->chase_reply, vq->orig_msg->rep);

        /* check signatures in the message; 
         * answer and authority must be valid, additional is only checked. */
        if(!validate_msg_signatures(qstate, qstate->env, ve, &vq->qchase, 
                vq->chase_reply, vq->key_entry)) {
                /* workaround bad recursor out there that truncates (even
                 * with EDNS4k) to 512 by removing RRSIG from auth section
                 * for positive replies*/
                if((subtype == VAL_CLASS_POSITIVE || subtype == VAL_CLASS_ANY
                        || subtype == VAL_CLASS_CNAME) &&
                        detect_wrongly_truncated(vq->orig_msg->rep)) {
                        /* truncate the message some more */
                        vq->orig_msg->rep->ns_numrrsets = 0;
                        vq->orig_msg->rep->ar_numrrsets = 0;
                        vq->orig_msg->rep->rrset_count = 
                                vq->orig_msg->rep->an_numrrsets;
                        vq->chase_reply->ns_numrrsets = 0;
                        vq->chase_reply->ar_numrrsets = 0;
                        vq->chase_reply->rrset_count = 
                                vq->chase_reply->an_numrrsets;
                        qstate->errinf = NULL;
                }
                else {
                        verbose(VERB_DETAIL, "Validate: message contains "
                                "bad rrsets");
                        return 1;
                }
        }

        switch(subtype) {
                case VAL_CLASS_POSITIVE:
                        verbose(VERB_ALGO, "Validating a positive response");
                        validate_positive_response(qstate->env, ve,
                                &vq->qchase, vq->chase_reply, vq->key_entry);
                        verbose(VERB_DETAIL, "validate(positive): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                case VAL_CLASS_NODATA:
                        verbose(VERB_ALGO, "Validating a nodata response");
                        validate_nodata_response(qstate->env, ve,
                                &vq->qchase, vq->chase_reply, vq->key_entry);
                        verbose(VERB_DETAIL, "validate(nodata): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                case VAL_CLASS_NAMEERROR:
                        rcode = (int)FLAGS_GET_RCODE(vq->orig_msg->rep->flags);
                        verbose(VERB_ALGO, "Validating a nxdomain response");
                        validate_nameerror_response(qstate->env, ve, 
                                &vq->qchase, vq->chase_reply, vq->key_entry, &rcode);
                        verbose(VERB_DETAIL, "validate(nxdomain): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        FLAGS_SET_RCODE(vq->orig_msg->rep->flags, rcode);
                        FLAGS_SET_RCODE(vq->chase_reply->flags, rcode);
                        break;

                case VAL_CLASS_CNAME:
                        verbose(VERB_ALGO, "Validating a cname response");
                        validate_cname_response(qstate->env, ve,
                                &vq->qchase, vq->chase_reply, vq->key_entry);
                        verbose(VERB_DETAIL, "validate(cname): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                case VAL_CLASS_CNAMENOANSWER:
                        verbose(VERB_ALGO, "Validating a cname noanswer "
                                "response");
                        validate_cname_noanswer_response(qstate->env, ve,
                                &vq->qchase, vq->chase_reply, vq->key_entry);
                        verbose(VERB_DETAIL, "validate(cname_noanswer): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                case VAL_CLASS_REFERRAL:
                        verbose(VERB_ALGO, "Validating a referral response");
                        validate_referral_response(vq->chase_reply);
                        verbose(VERB_DETAIL, "validate(referral): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                case VAL_CLASS_ANY:
                        verbose(VERB_ALGO, "Validating a positive ANY "
                                "response");
                        validate_any_response(qstate->env, ve, &vq->qchase, 
                                vq->chase_reply, vq->key_entry);
                        verbose(VERB_DETAIL, "validate(positive_any): %s",
                                sec_status_to_string(
                                vq->chase_reply->security));
                        break;

                default:
                        log_err("validate: unhandled response subtype: %d",
                                subtype);
        }
        if(vq->chase_reply->security == sec_status_bogus) {
                if(subtype == VAL_CLASS_POSITIVE)
                        errinf(qstate, "wildcard");
                else errinf(qstate, val_classification_to_string(subtype));
                errinf(qstate, "proof failed");
                errinf_origin(qstate, qstate->reply_origin);
        }

        return 1;
}

/**
 * Init DLV check.
 * DLV is going to be decommissioned, but the code is still here for some time.
 *
 * Called when a query is determined by other trust anchors to be insecure
 * (or indeterminate).  Then we look if there is a key in the DLV.
 * Performs aggressive negative cache check to see if there is no key.
 * Otherwise, spawns a DLV query, and changes to the DLV wait state.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 * @return  true if there is no DLV.
 *      false: processing is finished for the validator operate().
 *      This function may exit in three ways:
 *         o    no DLV (aggressive cache), so insecure. (true)
 *         o    error - stop processing (false)
 *         o    DLV lookup was started, stop processing (false)
 */
static int
val_dlv_init(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        uint8_t* nm;
        size_t nm_len;
        /* there must be a DLV configured */
        log_assert(qstate->env->anchors->dlv_anchor);
        /* this bool is true to avoid looping in the DLV checks */
        log_assert(vq->dlv_checked);

        /* init the DLV lookup variables */
        vq->dlv_lookup_name = NULL;
        vq->dlv_lookup_name_len = 0;
        vq->dlv_insecure_at = NULL;
        vq->dlv_insecure_at_len = 0;

        /* Determine the name for which we want to lookup DLV.
         * This name is for the current message, or 
         * for the current RRset for CNAME, referral subtypes.
         * If there is a signer, use that, otherwise the domain name */
        if(vq->signer_name) {
                nm = vq->signer_name;
                nm_len = vq->signer_len;
        } else {
                /* use qchase */
                nm = vq->qchase.qname;
                nm_len = vq->qchase.qname_len;
                if(vq->qchase.qtype == LDNS_RR_TYPE_DS)
                        dname_remove_label(&nm, &nm_len);
        }
        log_nametypeclass(VERB_ALGO, "DLV init look", nm, LDNS_RR_TYPE_DS,
                vq->qchase.qclass);
        log_assert(nm && nm_len);
        /* sanity check: no DLV lookups below the DLV anchor itself.
         * Like, an securely insecure delegation there makes no sense. */
        if(dname_subdomain_c(nm, qstate->env->anchors->dlv_anchor->name)) {
                verbose(VERB_ALGO, "DLV lookup within DLV repository denied");
                return 1;
        }
        /* concat name (minus root label) + dlv name */
        vq->dlv_lookup_name_len = nm_len - 1 + 
                qstate->env->anchors->dlv_anchor->namelen;
        vq->dlv_lookup_name = regional_alloc(qstate->region, 
                vq->dlv_lookup_name_len);
        if(!vq->dlv_lookup_name) {
                log_err("Out of memory preparing DLV lookup");
                return val_error(qstate, id);
        }
        memmove(vq->dlv_lookup_name, nm, nm_len-1);
        memmove(vq->dlv_lookup_name+nm_len-1, 
                qstate->env->anchors->dlv_anchor->name, 
                qstate->env->anchors->dlv_anchor->namelen);
        log_nametypeclass(VERB_ALGO, "DLV name", vq->dlv_lookup_name, 
                LDNS_RR_TYPE_DLV, vq->qchase.qclass);

        /* determine where the insecure point was determined, the DLV must 
         * be equal or below that to continue building the trust chain 
         * down. May be NULL if no trust chain was built yet */
        nm = NULL;
        if(vq->key_entry && key_entry_isnull(vq->key_entry)) {
                nm = vq->key_entry->name;
                nm_len = vq->key_entry->namelen;
        }
        if(nm) {
                vq->dlv_insecure_at_len = nm_len - 1 +
                        qstate->env->anchors->dlv_anchor->namelen;
                vq->dlv_insecure_at = regional_alloc(qstate->region,
                        vq->dlv_insecure_at_len);
                if(!vq->dlv_insecure_at) {
                        log_err("Out of memory preparing DLV lookup");
                        return val_error(qstate, id);
                }
                memmove(vq->dlv_insecure_at, nm, nm_len-1);
                memmove(vq->dlv_insecure_at+nm_len-1, 
                        qstate->env->anchors->dlv_anchor->name, 
                        qstate->env->anchors->dlv_anchor->namelen);
                log_nametypeclass(VERB_ALGO, "insecure_at", 
                        vq->dlv_insecure_at, 0, vq->qchase.qclass);
        }

        /* If we can find the name in the aggressive negative cache,
         * give up; insecure is the answer */
        while(val_neg_dlvlookup(ve->neg_cache, vq->dlv_lookup_name,
                vq->dlv_lookup_name_len, vq->qchase.qclass,
                qstate->env->rrset_cache, *qstate->env->now)) {
                /* go up */
                dname_remove_label(&vq->dlv_lookup_name, 
                        &vq->dlv_lookup_name_len);
                /* too high? */
                if(!dname_subdomain_c(vq->dlv_lookup_name,
                        qstate->env->anchors->dlv_anchor->name)) {
                        verbose(VERB_ALGO, "ask above dlv repo");
                        return 1; /* Above the repo is insecure */
                }
                /* above chain of trust? */
                if(vq->dlv_insecure_at && !dname_subdomain_c(
                        vq->dlv_lookup_name, vq->dlv_insecure_at)) {
                        verbose(VERB_ALGO, "ask above insecure endpoint");
                        return 1;
                }
        }

        /* perform a lookup for the DLV; with validation */
        vq->state = VAL_DLVLOOKUP_STATE;
        if(!generate_request(qstate, id, vq->dlv_lookup_name, 
                vq->dlv_lookup_name_len, LDNS_RR_TYPE_DLV,
                vq->qchase.qclass, 0)) {
                return val_error(qstate, id);
        }

        /* Find the closest encloser DLV from the repository.
         * then that is used to build another chain of trust 
         * This may first require a query 'too low' that has NSECs in
         * the answer, from which we determine the closest encloser DLV. 
         * When determine the closest encloser, skip empty nonterminals,
         * since we want a nonempty node in the DLV repository. */

        return 0;
}

/**
 * The Finished state. The validation status (good or bad) has been determined.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 * @return true if the event should be processed further on return, false if
 *         not.
 */
static int
processFinished(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        enum val_classification subtype = val_classify_response(
                qstate->query_flags, &qstate->qinfo, &vq->qchase, 
                vq->orig_msg->rep, vq->rrset_skip);

        /* if the result is insecure or indeterminate and we have not 
         * checked the DLV yet, check the DLV */
        if((vq->chase_reply->security == sec_status_insecure ||
                vq->chase_reply->security == sec_status_indeterminate) &&
                qstate->env->anchors->dlv_anchor && !vq->dlv_checked) {
                vq->dlv_checked = 1;
                if(!val_dlv_init(qstate, vq, ve, id))
                        return 0;
        }

        /* store overall validation result in orig_msg */
        if(vq->rrset_skip == 0)
                vq->orig_msg->rep->security = vq->chase_reply->security;
        else if(subtype != VAL_CLASS_REFERRAL ||
                vq->rrset_skip < vq->orig_msg->rep->an_numrrsets + 
                vq->orig_msg->rep->ns_numrrsets) {
                /* ignore sec status of additional section if a referral 
                 * type message skips there and
                 * use the lowest security status as end result. */
                if(vq->chase_reply->security < vq->orig_msg->rep->security)
                        vq->orig_msg->rep->security = 
                                vq->chase_reply->security;
        }

        if(subtype == VAL_CLASS_REFERRAL) {
                /* for a referral, move to next unchecked rrset and check it*/
                vq->rrset_skip = val_next_unchecked(vq->orig_msg->rep, 
                        vq->rrset_skip);
                if(vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
                        /* and restart for this rrset */
                        verbose(VERB_ALGO, "validator: go to next rrset");
                        vq->chase_reply->security = sec_status_unchecked;
                        vq->dlv_checked = 0; /* can do DLV for this RR */
                        vq->state = VAL_INIT_STATE;
                        return 1;
                }
                /* referral chase is done */
        }
        if(vq->chase_reply->security != sec_status_bogus &&
                subtype == VAL_CLASS_CNAME) {
                /* chase the CNAME; process next part of the message */
                if(!val_chase_cname(&vq->qchase, vq->orig_msg->rep, 
                        &vq->rrset_skip)) {
                        verbose(VERB_ALGO, "validator: failed to chase CNAME");
                        vq->orig_msg->rep->security = sec_status_bogus;
                } else {
                        /* restart process for new qchase at rrset_skip */
                        log_query_info(VERB_ALGO, "validator: chased to",
                                &vq->qchase);
                        vq->chase_reply->security = sec_status_unchecked;
                        vq->dlv_checked = 0; /* can do DLV for this RR */
                        vq->state = VAL_INIT_STATE;
                        return 1;
                }
        }

        if(vq->orig_msg->rep->security == sec_status_secure) {
                /* If the message is secure, check that all rrsets are
                 * secure (i.e. some inserted RRset for CNAME chain with
                 * a different signer name). And drop additional rrsets
                 * that are not secure (if clean-additional option is set) */
                /* this may cause the msg to be marked bogus */
                val_check_nonsecure(ve, vq->orig_msg->rep);
                if(vq->orig_msg->rep->security == sec_status_secure) {
                        log_query_info(VERB_DETAIL, "validation success", 
                                &qstate->qinfo);
                }
        }

        /* if the result is bogus - set message ttl to bogus ttl to avoid
         * endless bogus revalidation */
        if(vq->orig_msg->rep->security == sec_status_bogus) {
                /* see if we can try again to fetch data */
                if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
                        int restart_count = vq->restart_count+1;
                        verbose(VERB_ALGO, "validation failed, "
                                "blacklist and retry to fetch data");
                        val_blacklist(&qstate->blacklist, qstate->region, 
                                qstate->reply_origin, 0);
                        qstate->reply_origin = NULL;
                        qstate->errinf = NULL;
                        memset(vq, 0, sizeof(*vq));
                        vq->restart_count = restart_count;
                        vq->state = VAL_INIT_STATE;
                        verbose(VERB_ALGO, "pass back to next module");
                        qstate->ext_state[id] = module_restart_next;
                        return 0;
                }

                vq->orig_msg->rep->ttl = ve->bogus_ttl;
                vq->orig_msg->rep->prefetch_ttl = 
                        PREFETCH_TTL_CALC(vq->orig_msg->rep->ttl);
                if(qstate->env->cfg->val_log_level >= 1 &&
                        !qstate->env->cfg->val_log_squelch) {
                        if(qstate->env->cfg->val_log_level < 2)
                                log_query_info(0, "validation failure",
                                        &qstate->qinfo);
                        else {
                                char* err = errinf_to_str(qstate);
                                if(err) log_info("%s", err);
                                free(err);
                        }
                }
                /* If we are in permissive mode, bogus gets indeterminate */
                if(ve->permissive_mode)
                        vq->orig_msg->rep->security = sec_status_indeterminate;
        }

        /* store results in cache */
        if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) {
                /* if secure, this will override cache anyway, no need
                 * to check if from parentNS */
                if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo, 
                        vq->orig_msg->rep, 0, qstate->prefetch_leeway, 0, NULL,
                        qstate->query_flags)) {
                        log_err("out of memory caching validator results");
                }
        } else {
                /* for a referral, store the verified RRsets */
                /* and this does not get prefetched, so no leeway */
                if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo, 
                        vq->orig_msg->rep, 1, 0, 0, NULL,
                        qstate->query_flags)) {
                        log_err("out of memory caching validator results");
                }
        }
        qstate->return_rcode = LDNS_RCODE_NOERROR;
        qstate->return_msg = vq->orig_msg;
        qstate->ext_state[id] = module_finished;
        return 0;
}

/**
 * The DLVLookup state. Process DLV lookups.
 *
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 * @return true if the event should be processed further on return, false if
 *         not.
 */
static int
processDLVLookup(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        /* see if this we are ready to continue normal resolution */
        /* we may need more DLV lookups */
        if(vq->dlv_status==dlv_error)
                verbose(VERB_ALGO, "DLV woke up with status dlv_error");
        else if(vq->dlv_status==dlv_success)
                verbose(VERB_ALGO, "DLV woke up with status dlv_success");
        else if(vq->dlv_status==dlv_ask_higher)
                verbose(VERB_ALGO, "DLV woke up with status dlv_ask_higher");
        else if(vq->dlv_status==dlv_there_is_no_dlv)
                verbose(VERB_ALGO, "DLV woke up with status dlv_there_is_no_dlv");
        else    verbose(VERB_ALGO, "DLV woke up with status unknown");

        if(vq->dlv_status == dlv_error) {
                verbose(VERB_QUERY, "failed DLV lookup");
                return val_error(qstate, id);
        } else if(vq->dlv_status == dlv_success) {
                uint8_t* nm;
                size_t nmlen;
                /* chain continues with DNSKEY, continue in FINDKEY */
                vq->state = VAL_FINDKEY_STATE;

                /* strip off the DLV suffix from the name; could result in . */
                log_assert(dname_subdomain_c(vq->ds_rrset->rk.dname,
                        qstate->env->anchors->dlv_anchor->name));
                nmlen = vq->ds_rrset->rk.dname_len -
                        qstate->env->anchors->dlv_anchor->namelen + 1;
                nm = regional_alloc_init(qstate->region, 
                        vq->ds_rrset->rk.dname, nmlen);
                if(!nm) {
                        log_err("Out of memory in DLVLook");
                        return val_error(qstate, id);
                }
                nm[nmlen-1] = 0;

                vq->ds_rrset->rk.dname = nm;
                vq->ds_rrset->rk.dname_len = nmlen;

                /* create a nullentry for the key so the dnskey lookup
                 * can be retried after a validation failure for it */
                vq->key_entry = key_entry_create_null(qstate->region,
                        nm, nmlen, vq->qchase.qclass, 0, 0);
                if(!vq->key_entry) {
                        log_err("Out of memory in DLVLook");
                        return val_error(qstate, id);
                }

                if(!generate_request(qstate, id, vq->ds_rrset->rk.dname, 
                        vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY, 
                        vq->qchase.qclass, BIT_CD)) {
                        log_err("mem error generating DNSKEY request");
                        return val_error(qstate, id);
                }
                return 0;
        } else if(vq->dlv_status == dlv_there_is_no_dlv) {
                /* continue with the insecure result we got */
                vq->state = VAL_FINISHED_STATE;
                return 1;
        } 
        log_assert(vq->dlv_status == dlv_ask_higher);

        /* ask higher, make sure we stay in DLV repo, below dlv_at */
        if(!dname_subdomain_c(vq->dlv_lookup_name,
                qstate->env->anchors->dlv_anchor->name)) {
                /* just like, there is no DLV */
                verbose(VERB_ALGO, "ask above dlv repo");
                vq->state = VAL_FINISHED_STATE;
                return 1;
        }
        if(vq->dlv_insecure_at && !dname_subdomain_c(vq->dlv_lookup_name,
                vq->dlv_insecure_at)) {
                /* already checked a chain lower than dlv_lookup_name */
                verbose(VERB_ALGO, "ask above insecure endpoint");
                log_nametypeclass(VERB_ALGO, "enpt", vq->dlv_insecure_at, 0, 0);
                vq->state = VAL_FINISHED_STATE;
                return 1;
        }

        /* check negative cache before making new request */
        if(val_neg_dlvlookup(ve->neg_cache, vq->dlv_lookup_name,
                vq->dlv_lookup_name_len, vq->qchase.qclass,
                qstate->env->rrset_cache, *qstate->env->now)) {
                /* does not exist, go up one (go higher). */
                dname_remove_label(&vq->dlv_lookup_name, 
                        &vq->dlv_lookup_name_len);
                /* limit number of labels, limited number of recursion */
                return processDLVLookup(qstate, vq, ve, id);
        }

        if(!generate_request(qstate, id, vq->dlv_lookup_name,
                vq->dlv_lookup_name_len, LDNS_RR_TYPE_DLV, 
                vq->qchase.qclass, 0)) {
                return val_error(qstate, id);
        }

        return 0;
}

/** 
 * Handle validator state.
 * If a method returns true, the next state is started. If false, then
 * processing will stop.
 * @param qstate: query state.
 * @param vq: validator query state.
 * @param ve: validator shared global environment.
 * @param id: module id.
 */
static void
val_handle(struct module_qstate* qstate, struct val_qstate* vq, 
        struct val_env* ve, int id)
{
        int cont = 1;
        while(cont) {
                verbose(VERB_ALGO, "val handle processing q with state %s",
                        val_state_to_string(vq->state));
                switch(vq->state) {
                        case VAL_INIT_STATE:
                                cont = processInit(qstate, vq, ve, id);
                                break;
                        case VAL_FINDKEY_STATE: 
                                cont = processFindKey(qstate, vq, id);
                                break;
                        case VAL_VALIDATE_STATE: 
                                cont = processValidate(qstate, vq, ve, id);
                                break;
                        case VAL_FINISHED_STATE: 
                                cont = processFinished(qstate, vq, ve, id);
                                break;
                        case VAL_DLVLOOKUP_STATE: 
                                cont = processDLVLookup(qstate, vq, ve, id);
                                break;
                        default:
                                log_warn("validator: invalid state %d",
                                        vq->state);
                                cont = 0;
                                break;
                }
        }
}

void
val_operate(struct module_qstate* qstate, enum module_ev event, int id,
        struct outbound_entry* outbound)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
        struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
        verbose(VERB_QUERY, "validator[module %d] operate: extstate:%s "
                "event:%s", id, strextstate(qstate->ext_state[id]), 
                strmodulevent(event));
        log_query_info(VERB_QUERY, "validator operate: query",
                &qstate->qinfo);
        if(vq && qstate->qinfo.qname != vq->qchase.qname) 
                log_query_info(VERB_QUERY, "validator operate: chased to",
                &vq->qchase);
        (void)outbound;
        if(event == module_event_new || 
                (event == module_event_pass && vq == NULL)) {

                /* pass request to next module, to get it */
                verbose(VERB_ALGO, "validator: pass to next module");
                qstate->ext_state[id] = module_wait_module;
                return;
        }
        if(event == module_event_moddone) {
                /* check if validation is needed */
                verbose(VERB_ALGO, "validator: nextmodule returned");

                if(!needs_validation(qstate, qstate->return_rcode, 
                        qstate->return_msg)) {
                        /* no need to validate this */
                        if(qstate->return_msg)
                                qstate->return_msg->rep->security =
                                        sec_status_indeterminate;
                        qstate->ext_state[id] = module_finished;
                        return;
                }
                if(already_validated(qstate->return_msg)) {
                        qstate->ext_state[id] = module_finished;
                        return;
                }
                /* qclass ANY should have validation result from spawned 
                 * queries. If we get here, it is bogus or an internal error */
                if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
                        verbose(VERB_ALGO, "cannot validate classANY: bogus");
                        if(qstate->return_msg)
                                qstate->return_msg->rep->security =
                                        sec_status_bogus;
                        qstate->ext_state[id] = module_finished;
                        return;
                }
                /* create state to start validation */
                qstate->ext_state[id] = module_error; /* override this */
                if(!vq) {
                        vq = val_new(qstate, id);
                        if(!vq) {
                                log_err("validator: malloc failure");
                                qstate->ext_state[id] = module_error;
                                return;
                        }
                } else if(!vq->orig_msg) {
                        if(!val_new_getmsg(qstate, vq)) {
                                log_err("validator: malloc failure");
                                qstate->ext_state[id] = module_error;
                                return;
                        }
                }
                val_handle(qstate, vq, ve, id);
                return;
        }
        if(event == module_event_pass) {
                qstate->ext_state[id] = module_error; /* override this */
                /* continue processing, since val_env exists */
                val_handle(qstate, vq, ve, id);
                return;
        }
        log_err("validator: bad event %s", strmodulevent(event));
        qstate->ext_state[id] = module_error;
        return;
}

/**
 * Evaluate the response to a priming request.
 *
 * @param dnskey_rrset: DNSKEY rrset (can be NULL if none) in prime reply.
 *      (this rrset is allocated in the wrong region, not the qstate).
 * @param ta: trust anchor.
 * @param qstate: qstate that needs key.
 * @param id: module id.
 * @return new key entry or NULL on allocation failure.
 *      The key entry will either contain a validated DNSKEY rrset, or
 *      represent a Null key (query failed, but validation did not), or a
 *      Bad key (validation failed).
 */
static struct key_entry_key*
primeResponseToKE(struct ub_packed_rrset_key* dnskey_rrset, 
        struct trust_anchor* ta, struct module_qstate* qstate, int id)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
        struct key_entry_key* kkey = NULL;
        enum sec_status sec = sec_status_unchecked;
        char* reason = NULL;
        int downprot = qstate->env->cfg->harden_algo_downgrade;

        if(!dnskey_rrset) {
                log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
                        "could not fetch DNSKEY rrset", 
                        ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
                if(qstate->env->cfg->harden_dnssec_stripped) {
                        errinf(qstate, "no DNSKEY rrset");
                        kkey = key_entry_create_bad(qstate->region, ta->name,
                                ta->namelen, ta->dclass, BOGUS_KEY_TTL,
                                *qstate->env->now);
                } else  kkey = key_entry_create_null(qstate->region, ta->name,
                                ta->namelen, ta->dclass, NULL_KEY_TTL,
                                *qstate->env->now);
                if(!kkey) {
                        log_err("out of memory: allocate fail prime key");
                        return NULL;
                }
                return kkey;
        }
        /* attempt to verify with trust anchor DS and DNSKEY */
        kkey = val_verify_new_DNSKEYs_with_ta(qstate->region, qstate->env, ve, 
                dnskey_rrset, ta->ds_rrset, ta->dnskey_rrset, downprot,
                &reason);
        if(!kkey) {
                log_err("out of memory: verifying prime TA");
                return NULL;
        }
        if(key_entry_isgood(kkey))
                sec = sec_status_secure;
        else
                sec = sec_status_bogus;
        verbose(VERB_DETAIL, "validate keys with anchor(DS): %s", 
                sec_status_to_string(sec));

        if(sec != sec_status_secure) {
                log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
                        "DNSKEY rrset is not secure", 
                        ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
                /* NOTE: in this case, we should probably reject the trust 
                 * anchor for longer, perhaps forever. */
                if(qstate->env->cfg->harden_dnssec_stripped) {
                        errinf(qstate, reason);
                        kkey = key_entry_create_bad(qstate->region, ta->name,
                                ta->namelen, ta->dclass, BOGUS_KEY_TTL,
                                *qstate->env->now);
                } else  kkey = key_entry_create_null(qstate->region, ta->name,
                                ta->namelen, ta->dclass, NULL_KEY_TTL,
                                *qstate->env->now);
                if(!kkey) {
                        log_err("out of memory: allocate null prime key");
                        return NULL;
                }
                return kkey;
        }

        log_nametypeclass(VERB_DETAIL, "Successfully primed trust anchor", 
                ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
        return kkey;
}

/**
 * In inform supers, with the resulting message and rcode and the current
 * keyset in the super state, validate the DS response, returning a KeyEntry.
 *
 * @param qstate: query state that is validating and asked for a DS.
 * @param vq: validator query state
 * @param id: module id.
 * @param rcode: rcode result value.
 * @param msg: result message (if rcode is OK).
 * @param qinfo: from the sub query state, query info.
 * @param ke: the key entry to return. It returns
 *      is_bad if the DS response fails to validate, is_null if the
 *      DS response indicated an end to secure space, is_good if the DS
 *      validated. It returns ke=NULL if the DS response indicated that the
 *      request wasn't a delegation point.
 * @return 0 on servfail error (malloc failure).
 */
static int
ds_response_to_ke(struct module_qstate* qstate, struct val_qstate* vq,
        int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
        struct key_entry_key** ke)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
        char* reason = NULL;
        enum val_classification subtype;
        if(rcode != LDNS_RCODE_NOERROR) {
                char rc[16];
                rc[0]=0;
                (void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
                /* errors here pretty much break validation */
                verbose(VERB_DETAIL, "DS response was error, thus bogus");
                errinf(qstate, rc);
                errinf(qstate, "no DS");
                goto return_bogus;
        }

        subtype = val_classify_response(BIT_RD, qinfo, qinfo, msg->rep, 0);
        if(subtype == VAL_CLASS_POSITIVE) {
                struct ub_packed_rrset_key* ds;
                enum sec_status sec;
                ds = reply_find_answer_rrset(qinfo, msg->rep);
                /* If there was no DS rrset, then we have mis-classified 
                 * this message. */
                if(!ds) {
                        log_warn("internal error: POSITIVE DS response was "
                                "missing DS.");
                        errinf(qstate, "no DS record");
                        goto return_bogus;
                }
                /* Verify only returns BOGUS or SECURE. If the rrset is 
                 * bogus, then we are done. */
                sec = val_verify_rrset_entry(qstate->env, ve, ds, 
                        vq->key_entry, &reason);
                if(sec != sec_status_secure) {
                        verbose(VERB_DETAIL, "DS rrset in DS response did "
                                "not verify");
                        errinf(qstate, reason);
                        goto return_bogus;
                }

                /* If the DS rrset validates, we still have to make sure 
                 * that they are usable. */
                if(!val_dsset_isusable(ds)) {
                        /* If they aren't usable, then we treat it like 
                         * there was no DS. */
                        *ke = key_entry_create_null(qstate->region, 
                                qinfo->qname, qinfo->qname_len, qinfo->qclass, 
                                ub_packed_rrset_ttl(ds), *qstate->env->now);
                        return (*ke) != NULL;
                }

                /* Otherwise, we return the positive response. */
                log_query_info(VERB_DETAIL, "validated DS", qinfo);
                *ke = key_entry_create_rrset(qstate->region,
                        qinfo->qname, qinfo->qname_len, qinfo->qclass, ds,
                        NULL, *qstate->env->now);
                return (*ke) != NULL;
        } else if(subtype == VAL_CLASS_NODATA || 
                subtype == VAL_CLASS_NAMEERROR) {
                /* NODATA means that the qname exists, but that there was 
                 * no DS.  This is a pretty normal case. */
                time_t proof_ttl = 0;
                enum sec_status sec;

                /* make sure there are NSECs or NSEC3s with signatures */
                if(!val_has_signed_nsecs(msg->rep, &reason)) {
                        verbose(VERB_ALGO, "no NSECs: %s", reason);
                        errinf(qstate, reason);
                        goto return_bogus;
                }

                /* For subtype Name Error.
                 * attempt ANS 2.8.1.0 compatibility where it sets rcode
                 * to nxdomain, but really this is an Nodata/Noerror response.
                 * Find and prove the empty nonterminal in that case */

                /* Try to prove absence of the DS with NSEC */
                sec = val_nsec_prove_nodata_dsreply(
                        qstate->env, ve, qinfo, msg->rep, vq->key_entry, 
                        &proof_ttl, &reason);
                switch(sec) {
                        case sec_status_secure:
                                verbose(VERB_DETAIL, "NSEC RRset for the "
                                        "referral proved no DS.");
                                *ke = key_entry_create_null(qstate->region, 
                                        qinfo->qname, qinfo->qname_len, 
                                        qinfo->qclass, proof_ttl,
                                        *qstate->env->now);
                                return (*ke) != NULL;
                        case sec_status_insecure:
                                verbose(VERB_DETAIL, "NSEC RRset for the "
                                  "referral proved not a delegation point");
                                *ke = NULL;
                                return 1;
                        case sec_status_bogus:
                                verbose(VERB_DETAIL, "NSEC RRset for the "
                                        "referral did not prove no DS.");
                                errinf(qstate, reason);
                                goto return_bogus;
                        case sec_status_unchecked:
                        default:
                                /* NSEC proof did not work, try next */
                                break;
                }

                sec = nsec3_prove_nods(qstate->env, ve, 
                        msg->rep->rrsets + msg->rep->an_numrrsets,
                        msg->rep->ns_numrrsets, qinfo, vq->key_entry, &reason);
                switch(sec) {
                        case sec_status_insecure:
                                /* case insecure also continues to unsigned
                                 * space.  If nsec3-iter-count too high or
                                 * optout, then treat below as unsigned */
                        case sec_status_secure:
                                verbose(VERB_DETAIL, "NSEC3s for the "
                                        "referral proved no DS.");
                                *ke = key_entry_create_null(qstate->region, 
                                        qinfo->qname, qinfo->qname_len, 
                                        qinfo->qclass, proof_ttl,
                                        *qstate->env->now);
                                return (*ke) != NULL;
                        case sec_status_indeterminate:
                                verbose(VERB_DETAIL, "NSEC3s for the "
                                  "referral proved no delegation");
                                *ke = NULL;
                                return 1;
                        case sec_status_bogus:
                                verbose(VERB_DETAIL, "NSEC3s for the "
                                        "referral did not prove no DS.");
                                errinf(qstate, reason);
                                goto return_bogus;
                        case sec_status_unchecked:
                        default:
                                /* NSEC3 proof did not work */
                                break;
                }

                /* Apparently, no available NSEC/NSEC3 proved NODATA, so 
                 * this is BOGUS. */
                verbose(VERB_DETAIL, "DS %s ran out of options, so return "
                        "bogus", val_classification_to_string(subtype));
                errinf(qstate, "no DS but also no proof of that");
                goto return_bogus;
        } else if(subtype == VAL_CLASS_CNAME || 
                subtype == VAL_CLASS_CNAMENOANSWER) {
                /* if the CNAME matches the exact name we want and is signed
                 * properly, then also, we are sure that no DS exists there,
                 * much like a NODATA proof */
                enum sec_status sec;
                struct ub_packed_rrset_key* cname;
                cname = reply_find_rrset_section_an(msg->rep, qinfo->qname,
                        qinfo->qname_len, LDNS_RR_TYPE_CNAME, qinfo->qclass);
                if(!cname) {
                        errinf(qstate, "validator classified CNAME but no "
                                "CNAME of the queried name for DS");
                        goto return_bogus;
                }
                if(((struct packed_rrset_data*)cname->entry.data)->rrsig_count
                        == 0) {
                        if(msg->rep->an_numrrsets != 0 && ntohs(msg->rep->
                                rrsets[0]->rk.type)==LDNS_RR_TYPE_DNAME) {
                                errinf(qstate, "DS got DNAME answer");
                        } else {
                                errinf(qstate, "DS got unsigned CNAME answer");
                        }
                        goto return_bogus;
                }
                sec = val_verify_rrset_entry(qstate->env, ve, cname, 
                        vq->key_entry, &reason);
                if(sec == sec_status_secure) {
                        verbose(VERB_ALGO, "CNAME validated, "
                                "proof that DS does not exist");
                        /* and that it is not a referral point */
                        *ke = NULL;
                        return 1;
                }
                errinf(qstate, "CNAME in DS response was not secure.");
                errinf(qstate, reason);
                goto return_bogus;
        } else {
                verbose(VERB_QUERY, "Encountered an unhandled type of "
                        "DS response, thus bogus.");
                errinf(qstate, "no DS and");
                if(FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NOERROR) {
                        char rc[16];
                        rc[0]=0;
                        (void)sldns_wire2str_rcode_buf((int)FLAGS_GET_RCODE(
                                msg->rep->flags), rc, sizeof(rc));
                        errinf(qstate, rc);
                } else  errinf(qstate, val_classification_to_string(subtype));
                errinf(qstate, "message fails to prove that");
                goto return_bogus;
        }
return_bogus:
        *ke = key_entry_create_bad(qstate->region, qinfo->qname,
                qinfo->qname_len, qinfo->qclass, 
                BOGUS_KEY_TTL, *qstate->env->now);
        return (*ke) != NULL;
}

/**
 * Process DS response. Called from inform_supers.
 * Because it is in inform_supers, the mesh itself is busy doing callbacks
 * for a state that is to be deleted soon; don't touch the mesh; instead
 * set a state in the super, as the super will be reactivated soon.
 * Perform processing to determine what state to set in the super.
 *
 * @param qstate: query state that is validating and asked for a DS.
 * @param vq: validator query state
 * @param id: module id.
 * @param rcode: rcode result value.
 * @param msg: result message (if rcode is OK).
 * @param qinfo: from the sub query state, query info.
 * @param origin: the origin of msg.
 */
static void
process_ds_response(struct module_qstate* qstate, struct val_qstate* vq,
        int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
        struct sock_list* origin)
{
        struct key_entry_key* dske = NULL;
        uint8_t* olds = vq->empty_DS_name;
        vq->empty_DS_name = NULL;
        if(!ds_response_to_ke(qstate, vq, id, rcode, msg, qinfo, &dske)) {
                        log_err("malloc failure in process_ds_response");
                        vq->key_entry = NULL; /* make it error */
                        vq->state = VAL_VALIDATE_STATE;
                        return;
        }
        if(dske == NULL) {
                vq->empty_DS_name = regional_alloc_init(qstate->region,
                        qinfo->qname, qinfo->qname_len);
                if(!vq->empty_DS_name) {
                        log_err("malloc failure in empty_DS_name");
                        vq->key_entry = NULL; /* make it error */
                        vq->state = VAL_VALIDATE_STATE;
                        return;
                }
                vq->empty_DS_len = qinfo->qname_len;
                vq->chain_blacklist = NULL;
                /* ds response indicated that we aren't on a delegation point.
                 * Keep the forState.state on FINDKEY. */
        } else if(key_entry_isgood(dske)) {
                vq->ds_rrset = key_entry_get_rrset(dske, qstate->region);
                if(!vq->ds_rrset) {
                        log_err("malloc failure in process DS");
                        vq->key_entry = NULL; /* make it error */
                        vq->state = VAL_VALIDATE_STATE;
                        return;
                }
                vq->chain_blacklist = NULL; /* fresh blacklist for next part*/
                /* Keep the forState.state on FINDKEY. */
        } else if(key_entry_isbad(dske) 
                && vq->restart_count < VAL_MAX_RESTART_COUNT) {
                vq->empty_DS_name = olds;
                val_blacklist(&vq->chain_blacklist, qstate->region, origin, 1);
                qstate->errinf = NULL;
                vq->restart_count++;
        } else {
                if(key_entry_isbad(dske)) {
                        errinf_origin(qstate, origin);
                        errinf_dname(qstate, "for DS", qinfo->qname);
                }
                /* NOTE: the reason for the DS to be not good (that is, 
                 * either bad or null) should have been logged by 
                 * dsResponseToKE. */
                vq->key_entry = dske;
                /* The FINDKEY phase has ended, so move on. */
                vq->state = VAL_VALIDATE_STATE;
        }
}

/**
 * Process DNSKEY response. Called from inform_supers.
 * Sets the key entry in the state.
 * Because it is in inform_supers, the mesh itself is busy doing callbacks
 * for a state that is to be deleted soon; don't touch the mesh; instead
 * set a state in the super, as the super will be reactivated soon.
 * Perform processing to determine what state to set in the super.
 *
 * @param qstate: query state that is validating and asked for a DNSKEY.
 * @param vq: validator query state
 * @param id: module id.
 * @param rcode: rcode result value.
 * @param msg: result message (if rcode is OK).
 * @param qinfo: from the sub query state, query info.
 * @param origin: the origin of msg.
 */
static void
process_dnskey_response(struct module_qstate* qstate, struct val_qstate* vq,
        int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
        struct sock_list* origin)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
        struct key_entry_key* old = vq->key_entry;
        struct ub_packed_rrset_key* dnskey = NULL;
        int downprot;
        char* reason = NULL;

        if(rcode == LDNS_RCODE_NOERROR)
                dnskey = reply_find_answer_rrset(qinfo, msg->rep);

        if(dnskey == NULL) {
                /* bad response */
                verbose(VERB_DETAIL, "Missing DNSKEY RRset in response to "
                        "DNSKEY query.");
                if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
                        val_blacklist(&vq->chain_blacklist, qstate->region,
                                origin, 1);
                        qstate->errinf = NULL;
                        vq->restart_count++;
                        return;
                }
                vq->key_entry = key_entry_create_bad(qstate->region, 
                        qinfo->qname, qinfo->qname_len, qinfo->qclass,
                        BOGUS_KEY_TTL, *qstate->env->now);
                if(!vq->key_entry) {
                        log_err("alloc failure in missing dnskey response");
                        /* key_entry is NULL for failure in Validate */
                }
                errinf(qstate, "No DNSKEY record");
                errinf_origin(qstate, origin);
                errinf_dname(qstate, "for key", qinfo->qname);
                vq->state = VAL_VALIDATE_STATE;
                return;
        }
        if(!vq->ds_rrset) {
                log_err("internal error: no DS rrset for new DNSKEY response");
                vq->key_entry = NULL;
                vq->state = VAL_VALIDATE_STATE;
                return;
        }
        downprot = qstate->env->cfg->harden_algo_downgrade;
        vq->key_entry = val_verify_new_DNSKEYs(qstate->region, qstate->env,
                ve, dnskey, vq->ds_rrset, downprot, &reason);

        if(!vq->key_entry) {
                log_err("out of memory in verify new DNSKEYs");
                vq->state = VAL_VALIDATE_STATE;
                return;
        }
        /* If the key entry isBad or isNull, then we can move on to the next
         * state. */
        if(!key_entry_isgood(vq->key_entry)) {
                if(key_entry_isbad(vq->key_entry)) {
                        if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
                                val_blacklist(&vq->chain_blacklist, 
                                        qstate->region, origin, 1);
                                qstate->errinf = NULL;
                                vq->restart_count++;
                                vq->key_entry = old;
                                return;
                        }
                        verbose(VERB_DETAIL, "Did not match a DS to a DNSKEY, "
                                "thus bogus.");
                        errinf(qstate, reason);
                        errinf_origin(qstate, origin);
                        errinf_dname(qstate, "for key", qinfo->qname);
                }
                vq->chain_blacklist = NULL;
                vq->state = VAL_VALIDATE_STATE;
                return;
        }
        vq->chain_blacklist = NULL;
        qstate->errinf = NULL;

        /* The DNSKEY validated, so cache it as a trusted key rrset. */
        key_cache_insert(ve->kcache, vq->key_entry, qstate);

        /* If good, we stay in the FINDKEY state. */
        log_query_info(VERB_DETAIL, "validated DNSKEY", qinfo);
}

/**
 * Process prime response
 * Sets the key entry in the state.
 *
 * @param qstate: query state that is validating and primed a trust anchor.
 * @param vq: validator query state
 * @param id: module id.
 * @param rcode: rcode result value.
 * @param msg: result message (if rcode is OK).
 * @param origin: the origin of msg.
 */
static void
process_prime_response(struct module_qstate* qstate, struct val_qstate* vq,
        int id, int rcode, struct dns_msg* msg, struct sock_list* origin)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
        struct ub_packed_rrset_key* dnskey_rrset = NULL;
        struct trust_anchor* ta = anchor_find(qstate->env->anchors, 
                vq->trust_anchor_name, vq->trust_anchor_labs,
                vq->trust_anchor_len, vq->qchase.qclass);
        if(!ta) {
                /* trust anchor revoked, restart with less anchors */
                vq->state = VAL_INIT_STATE;
                if(!vq->trust_anchor_name)
                        vq->state = VAL_VALIDATE_STATE; /* break a loop */
                vq->trust_anchor_name = NULL;
                return;
        }
        /* Fetch and validate the keyEntry that corresponds to the 
         * current trust anchor. */
        if(rcode == LDNS_RCODE_NOERROR) {
                dnskey_rrset = reply_find_rrset_section_an(msg->rep,
                        ta->name, ta->namelen, LDNS_RR_TYPE_DNSKEY,
                        ta->dclass);
        }
        if(ta->autr) {
                if(!autr_process_prime(qstate->env, ve, ta, dnskey_rrset)) {
                        /* trust anchor revoked, restart with less anchors */
                        vq->state = VAL_INIT_STATE;
                        vq->trust_anchor_name = NULL;
                        return;
                }
        }
        vq->key_entry = primeResponseToKE(dnskey_rrset, ta, qstate, id);
        lock_basic_unlock(&ta->lock);
        if(vq->key_entry) {
                if(key_entry_isbad(vq->key_entry) 
                        && vq->restart_count < VAL_MAX_RESTART_COUNT) {
                        val_blacklist(&vq->chain_blacklist, qstate->region, 
                                origin, 1);
                        qstate->errinf = NULL;
                        vq->restart_count++;
                        vq->key_entry = NULL;
                        vq->state = VAL_INIT_STATE;
                        return;
                } 
                vq->chain_blacklist = NULL;
                errinf_origin(qstate, origin);
                errinf_dname(qstate, "for trust anchor", ta->name);
                /* store the freshly primed entry in the cache */
                key_cache_insert(ve->kcache, vq->key_entry, qstate);
        }

        /* If the result of the prime is a null key, skip the FINDKEY state.*/
        if(!vq->key_entry || key_entry_isnull(vq->key_entry) ||
                key_entry_isbad(vq->key_entry)) {
                vq->state = VAL_VALIDATE_STATE;
        }
        /* the qstate will be reactivated after inform_super is done */
}

/**
 * Process DLV response. Called from inform_supers.
 * Because it is in inform_supers, the mesh itself is busy doing callbacks
 * for a state that is to be deleted soon; don't touch the mesh; instead
 * set a state in the super, as the super will be reactivated soon.
 * Perform processing to determine what state to set in the super.
 *
 * @param qstate: query state that is validating and asked for a DLV.
 * @param vq: validator query state
 * @param id: module id.
 * @param rcode: rcode result value.
 * @param msg: result message (if rcode is OK).
 * @param qinfo: from the sub query state, query info.
 */
static void
process_dlv_response(struct module_qstate* qstate, struct val_qstate* vq,
        int id, int rcode, struct dns_msg* msg, struct query_info* qinfo)
{
        struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];

        verbose(VERB_ALGO, "process dlv response to super");
        if(rcode != LDNS_RCODE_NOERROR) {
                /* lookup failed, set in vq to give up */
                vq->dlv_status = dlv_error;
                verbose(VERB_ALGO, "response is error");
                return;
        }
        if(msg->rep->security != sec_status_secure) {
                vq->dlv_status = dlv_error;
                verbose(VERB_ALGO, "response is not secure, %s",
                        sec_status_to_string(msg->rep->security));
                return;
        }
        /* was the lookup a success? validated DLV? */
        if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_NOERROR &&
                msg->rep->an_numrrsets == 1 &&
                msg->rep->security == sec_status_secure &&
                ntohs(msg->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DLV &&
                ntohs(msg->rep->rrsets[0]->rk.rrset_class) == qinfo->qclass &&
                query_dname_compare(msg->rep->rrsets[0]->rk.dname, 
                        vq->dlv_lookup_name) == 0) {
                /* yay! it is just like a DS */
                vq->ds_rrset = (struct ub_packed_rrset_key*)
                        regional_alloc_init(qstate->region,
                        msg->rep->rrsets[0], sizeof(*vq->ds_rrset));
                if(!vq->ds_rrset) {
                        log_err("out of memory in process_dlv");
                        return;
                }
                vq->ds_rrset->entry.key = vq->ds_rrset;
                vq->ds_rrset->rk.dname = (uint8_t*)regional_alloc_init(
                        qstate->region, vq->ds_rrset->rk.dname, 
                        vq->ds_rrset->rk.dname_len);
                if(!vq->ds_rrset->rk.dname) {
                        log_err("out of memory in process_dlv");
                        vq->dlv_status = dlv_error;
                        return;
                }
                vq->ds_rrset->entry.data = regional_alloc_init(qstate->region,
                        vq->ds_rrset->entry.data, 
                        packed_rrset_sizeof(vq->ds_rrset->entry.data));
                if(!vq->ds_rrset->entry.data) {
                        log_err("out of memory in process_dlv");
                        vq->dlv_status = dlv_error;
                        return;
                }
                packed_rrset_ptr_fixup(vq->ds_rrset->entry.data);
                /* make vq do a DNSKEY query next up */
                vq->dlv_status = dlv_success;
                return;
        }
        /* store NSECs into negative cache */
        val_neg_addreply(ve->neg_cache, msg->rep);

        /* was the lookup a failure? 
         *   if we have to go up into the DLV for a higher DLV anchor
         *   then set this in the vq, so it can make queries when activated.
         * See if the NSECs indicate that we should look for higher DLV
         * or, that there is no DLV securely */
        if(!val_nsec_check_dlv(qinfo, msg->rep, &vq->dlv_lookup_name, 
                &vq->dlv_lookup_name_len)) {
                vq->dlv_status = dlv_error;
                verbose(VERB_ALGO, "nsec error");
                return;
        }
        if(!dname_subdomain_c(vq->dlv_lookup_name, 
                qstate->env->anchors->dlv_anchor->name)) {
                vq->dlv_status = dlv_there_is_no_dlv;
                return;
        }
        vq->dlv_status = dlv_ask_higher;
}

/* 
 * inform validator super.
 * 
 * @param qstate: query state that finished.
 * @param id: module id.
 * @param super: the qstate to inform.
 */
void
val_inform_super(struct module_qstate* qstate, int id,
        struct module_qstate* super)
{
        struct val_qstate* vq = (struct val_qstate*)super->minfo[id];
        log_query_info(VERB_ALGO, "validator: inform_super, sub is",
                &qstate->qinfo);
        log_query_info(VERB_ALGO, "super is", &super->qinfo);
        if(!vq) {
                verbose(VERB_ALGO, "super: has no validator state");
                return;
        }
        if(vq->wait_prime_ta) {
                vq->wait_prime_ta = 0;
                process_prime_response(super, vq, id, qstate->return_rcode,
                        qstate->return_msg, qstate->reply_origin);
                return;
        }
        if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS) {
                process_ds_response(super, vq, id, qstate->return_rcode,
                        qstate->return_msg, &qstate->qinfo, 
                        qstate->reply_origin);
                return;
        } else if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY) {
                process_dnskey_response(super, vq, id, qstate->return_rcode,
                        qstate->return_msg, &qstate->qinfo,
                        qstate->reply_origin);
                return;
        } else if(qstate->qinfo.qtype == LDNS_RR_TYPE_DLV) {
                process_dlv_response(super, vq, id, qstate->return_rcode,
                        qstate->return_msg, &qstate->qinfo);
                return;
        }
        log_err("internal error in validator: no inform_supers possible");
}

void
val_clear(struct module_qstate* qstate, int id)
{
        if(!qstate)
                return;
        /* everything is allocated in the region, so assign NULL */
        qstate->minfo[id] = NULL;
}

size_t 
val_get_mem(struct module_env* env, int id)
{
        struct val_env* ve = (struct val_env*)env->modinfo[id];
        if(!ve)
                return 0;
        return sizeof(*ve) + key_cache_get_mem(ve->kcache) + 
                val_neg_get_mem(ve->neg_cache) +
                sizeof(size_t)*2*ve->nsec3_keyiter_count;
}

/**
 * The validator function block 
 */
static struct module_func_block val_block = {
        "validator",
        &val_init, &val_deinit, &val_operate, &val_inform_super, &val_clear,
        &val_get_mem
};

struct module_func_block* 
val_get_funcblock(void)
{
        return &val_block;
}

const char* 
val_state_to_string(enum val_state state)
{
        switch(state) {
                case VAL_INIT_STATE: return "VAL_INIT_STATE";
                case VAL_FINDKEY_STATE: return "VAL_FINDKEY_STATE";
                case VAL_VALIDATE_STATE: return "VAL_VALIDATE_STATE";
                case VAL_FINISHED_STATE: return "VAL_FINISHED_STATE";
                case VAL_DLVLOOKUP_STATE: return "VAL_DLVLOOKUP_STATE";
        }
        return "UNKNOWN VALIDATOR STATE";
}