/src/bind9/lib/dns/zoneverify.c

Source
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <inttypes.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

#include <isc/base32.h>
#include <isc/buffer.h>
#include <isc/heap.h>
#include <isc/iterated_hash.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/region.h>
#include <isc/result.h>
#include <isc/types.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/dnssec.h>
#include <dns/fixedname.h>
#include <dns/keytable.h>
#include <dns/keyvalues.h>
#include <dns/name.h>
#include <dns/nsec.h>
#include <dns/nsec3.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/secalg.h>
#include <dns/types.h>
#include <dns/zone.h>
#include <dns/zoneverify.h>

#include <dst/dst.h>

typedef struct vctx {
  isc_mem_t *mctx;
  dns_zone_t *zone;
  dns_db_t *db;
  dns_dbversion_t *ver;
  dns_name_t *origin;
  dns_keytable_t *secroots;
  bool goodksk;
  bool goodzsk;
  dns_rdataset_t keyset;
  dns_rdataset_t keysigs;
  dns_rdataset_t soaset;
  dns_rdataset_t soasigs;
  dns_rdataset_t nsecset;
  dns_rdataset_t nsecsigs;
  dns_rdataset_t nsec3paramset;
  dns_rdataset_t nsec3paramsigs;
  unsigned char revoked_ksk[DST_MAX_ALGS];
  unsigned char revoked_zsk[DST_MAX_ALGS];
  unsigned char standby_ksk[DST_MAX_ALGS];
  unsigned char standby_zsk[DST_MAX_ALGS];
  unsigned char ksk_algorithms[DST_MAX_ALGS];
  unsigned char zsk_algorithms[DST_MAX_ALGS];
  unsigned char bad_algorithms[DST_MAX_ALGS];
  unsigned char act_algorithms[DST_MAX_ALGS];
  isc_heap_t *expected_chains;
  isc_heap_t *found_chains;
} vctx_t;

struct nsec3_chain_fixed {
  uint8_t hash;
  uint8_t salt_length;
  uint8_t next_length;
  uint16_t iterations;
  /*
   * The following non-fixed-length data is stored in memory after the
   * fields declared above for each NSEC3 chain element:
   *
   * unsigned char  salt[salt_length];
   * unsigned char  owner[next_length];
   * unsigned char  next[next_length];
   */
};

/*
 * Helper function used to calculate length of variable-length
 * data section in object pointed to by 'chain'.
 */
static size_t
chain_length(struct nsec3_chain_fixed *chain) {
  return chain->salt_length + 2 * chain->next_length;
}

/*%
 * Log a zone verification error described by 'fmt' and the variable arguments
 * following it.  Either use dns_zone_logv() or print to stderr, depending on
 * whether the function was invoked from within named or by a standalone tool,
 * respectively.
 */
static void
zoneverify_log_error(const vctx_t *vctx, const char *fmt, ...) {
  va_list ap;

  va_start(ap, fmt);
  if (vctx->zone != NULL) {
    dns_zone_logv(vctx->zone, DNS_LOGCATEGORY_GENERAL,
            ISC_LOG_ERROR, NULL, fmt, ap);
  } else {
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
  }
  va_end(ap);
}

static bool
is_delegation(const vctx_t *vctx, const dns_name_t *name, dns_dbnode_t *node,
        uint32_t *ttlp) {
  dns_rdataset_t nsset;
  isc_result_t result;

  if (dns_name_equal(name, vctx->origin)) {
    return false;
  }

  dns_rdataset_init(&nsset);
  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_ns, 0, 0, &nsset, NULL);
  if (dns_rdataset_isassociated(&nsset)) {
    SET_IF_NOT_NULL(ttlp, nsset.ttl);
    dns_rdataset_disassociate(&nsset);
  }

  return result == ISC_R_SUCCESS;
}

/*%
 * Return true if version 'ver' of database 'db' contains a DNAME RRset at
 * 'node'; return false otherwise.
 */
static bool
has_dname(const vctx_t *vctx, dns_dbnode_t *node) {
  dns_rdataset_t dnameset;
  isc_result_t result;

  dns_rdataset_init(&dnameset);
  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_dname, 0, 0, &dnameset,
             NULL);
  if (dns_rdataset_isassociated(&dnameset)) {
    dns_rdataset_disassociate(&dnameset);
  }

  return result == ISC_R_SUCCESS;
}

static bool
goodsig(const vctx_t *vctx, dns_rdata_t *sigrdata, const dns_name_t *name,
  dst_key_t **dstkeys, size_t nkeys, dns_rdataset_t *rdataset) {
  dns_rdata_rrsig_t sig;
  isc_result_t result;
  dst_algorithm_t algorithm;

  result = dns_rdata_tostruct(sigrdata, &sig, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  algorithm = dst_algorithm_fromdata(sig.algorithm, sig.signature,
             sig.siglen);

  for (size_t key = 0; key < nkeys; key++) {
    if (algorithm != dst_key_alg(dstkeys[key]) ||
        sig.keyid != dst_key_id(dstkeys[key]) ||
        !dns_name_equal(&sig.signer, vctx->origin))
    {
      continue;
    }
    result = dns_dnssec_verify(name, rdataset, dstkeys[key], false,
             vctx->mctx, sigrdata, NULL);
    if (result == ISC_R_SUCCESS || result == DNS_R_FROMWILDCARD) {
      return true;
    }
  }
  return false;
}

static bool
nsec_bitmap_equal(dns_rdata_nsec_t *nsec, dns_rdata_t *rdata) {
  isc_result_t result;
  dns_rdata_nsec_t tmpnsec;

  result = dns_rdata_tostruct(rdata, &tmpnsec, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  if (nsec->len != tmpnsec.len ||
      memcmp(nsec->typebits, tmpnsec.typebits, nsec->len) != 0)
  {
    return false;
  }
  return true;
}

static isc_result_t
verifynsec(const vctx_t *vctx, const dns_name_t *name, dns_dbnode_t *node,
     const dns_name_t *nextname, isc_result_t *vresult) {
  unsigned char buffer[DNS_NSEC_BUFFERSIZE];
  char namebuf[DNS_NAME_FORMATSIZE];
  char nextbuf[DNS_NAME_FORMATSIZE];
  char found[DNS_NAME_FORMATSIZE];
  dns_rdataset_t rdataset;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdata_t tmprdata = DNS_RDATA_INIT;
  dns_rdata_nsec_t nsec;
  isc_result_t result;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_nsec, 0, 0, &rdataset, NULL);
  if (result != ISC_R_SUCCESS) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx, "Missing NSEC record for %s",
             namebuf);
    *vresult = ISC_R_FAILURE;
    result = ISC_R_SUCCESS;
    goto done;
  }

  result = dns_rdataset_first(&rdataset);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_rdataset_first(): %s",
             isc_result_totext(result));
    goto done;
  }

  dns_rdataset_current(&rdataset, &rdata);
  result = dns_rdata_tostruct(&rdata, &nsec, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  /* Check next name is consistent */
  if (!dns_name_equal(&nsec.next, nextname)) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_name_format(nextname, nextbuf, sizeof(nextbuf));
    dns_name_format(&nsec.next, found, sizeof(found));
    zoneverify_log_error(vctx,
             "Bad NSEC record for %s, next name "
             "mismatch (expected:%s, found:%s)",
             namebuf, nextbuf, found);
    *vresult = ISC_R_FAILURE;
    goto done;
  }

  /* Check bit map is consistent */
  result = dns_nsec_buildrdata(vctx->db, vctx->ver, node, nextname,
             buffer, &tmprdata);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_nsec_buildrdata(): %s",
             isc_result_totext(result));
    goto done;
  }
  if (!nsec_bitmap_equal(&nsec, &tmprdata)) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx,
             "Bad NSEC record for %s, bit map "
             "mismatch",
             namebuf);
    *vresult = ISC_R_FAILURE;
    goto done;
  }

  result = dns_rdataset_next(&rdataset);
  if (result != ISC_R_NOMORE) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx, "Multiple NSEC records for %s",
             namebuf);
    *vresult = ISC_R_FAILURE;
    goto done;
  }

  *vresult = ISC_R_SUCCESS;
  result = ISC_R_SUCCESS;

done:
  if (dns_rdataset_isassociated(&rdataset)) {
    dns_rdataset_disassociate(&rdataset);
  }

  return result;
}

static isc_result_t
check_no_rrsig(const vctx_t *vctx, const dns_rdataset_t *rdataset,
         const dns_name_t *name, dns_dbnode_t *node) {
  char namebuf[DNS_NAME_FORMATSIZE];
  char typebuf[DNS_RDATATYPE_FORMATSIZE];
  dns_rdataset_t sigrdataset = DNS_RDATASET_INIT;
  dns_rdatasetiter_t *rdsiter = NULL;
  isc_result_t result;

  dns_rdataset_init(&sigrdataset);
  result = dns_db_allrdatasets(vctx->db, node, vctx->ver, 0, 0, &rdsiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_allrdatasets(): %s",
             isc_result_totext(result));
    return result;
  }
  DNS_RDATASETITER_FOREACH(rdsiter) {
    dns_rdatasetiter_current(rdsiter, &sigrdataset);
    if (sigrdataset.type == dns_rdatatype_rrsig &&
        sigrdataset.covers == rdataset->type)
    {
      dns_name_format(name, namebuf, sizeof(namebuf));
      dns_rdatatype_format(rdataset->type, typebuf,
               sizeof(typebuf));
      zoneverify_log_error(
        vctx,
        "Warning: Found unexpected signatures "
        "for %s/%s",
        namebuf, typebuf);
      break;
    }
    dns_rdataset_disassociate(&sigrdataset);
  }
  if (dns_rdataset_isassociated(&sigrdataset)) {
    dns_rdataset_disassociate(&sigrdataset);
  }
  dns_rdatasetiter_destroy(&rdsiter);

  return ISC_R_SUCCESS;
}

static bool
chain_compare(void *arg1, void *arg2) {
  struct nsec3_chain_fixed *e1 = arg1, *e2 = arg2;
  /*
   * Do each element in turn to get a stable sort.
   */
  if (e1->hash < e2->hash) {
    return true;
  }
  if (e1->hash > e2->hash) {
    return false;
  }
  if (e1->iterations < e2->iterations) {
    return true;
  }
  if (e1->iterations > e2->iterations) {
    return false;
  }
  if (e1->salt_length < e2->salt_length) {
    return true;
  }
  if (e1->salt_length > e2->salt_length) {
    return false;
  }
  if (e1->next_length < e2->next_length) {
    return true;
  }
  if (e1->next_length > e2->next_length) {
    return false;
  }
  if (memcmp(e1 + 1, e2 + 1, chain_length(e1)) < 0) {
    return true;
  }
  return false;
}

static bool
chain_equal(const struct nsec3_chain_fixed *e1,
      const struct nsec3_chain_fixed *e2, size_t data_length) {
  if (e1->hash != e2->hash) {
    return false;
  }
  if (e1->iterations != e2->iterations) {
    return false;
  }
  if (e1->salt_length != e2->salt_length) {
    return false;
  }
  if (e1->next_length != e2->next_length) {
    return false;
  }

  return memcmp(e1 + 1, e2 + 1, data_length) == 0;
}

static void
record_nsec3(const vctx_t *vctx, const unsigned char *rawhash,
       const dns_rdata_nsec3_t *nsec3, isc_heap_t *chains) {
  struct nsec3_chain_fixed *element = NULL;
  unsigned char *cp = NULL;
  size_t len;

  len = sizeof(*element) + nsec3->next_length * 2 + nsec3->salt_length;

  element = isc_mem_get(vctx->mctx, len);
  *element = (struct nsec3_chain_fixed){
    .hash = nsec3->hash,
    .salt_length = nsec3->salt_length,
    .next_length = nsec3->next_length,
    .iterations = nsec3->iterations,
  };
  cp = (unsigned char *)(element + 1);
  memmove(cp, nsec3->salt, nsec3->salt_length);
  cp += nsec3->salt_length;
  memmove(cp, rawhash, nsec3->next_length);
  cp += nsec3->next_length;
  memmove(cp, nsec3->next, nsec3->next_length);
  isc_heap_insert(chains, element);
}

/*
 * Check whether any NSEC3 within 'rdataset' matches the parameters in
 * 'nsec3param'.
 */
static isc_result_t
find_nsec3_match(const dns_rdata_nsec3param_t *nsec3param,
     dns_rdataset_t *rdataset, size_t rhsize,
     dns_rdata_nsec3_t *nsec3_match) {
  /*
   * Find matching NSEC3 record.
   */
  DNS_RDATASET_FOREACH(rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(rdataset, &rdata);
    dns_rdata_tostruct(&rdata, nsec3_match, NULL);
    if (nsec3_match->hash == nsec3param->hash &&
        nsec3_match->next_length == rhsize &&
        nsec3_match->iterations == nsec3param->iterations &&
        nsec3_match->salt_length == nsec3param->salt_length &&
        memcmp(nsec3_match->salt, nsec3param->salt,
         nsec3param->salt_length) == 0)
    {
      return ISC_R_SUCCESS;
    }
  }

  return ISC_R_NOTFOUND;
}

static isc_result_t
match_nsec3(const vctx_t *vctx, const dns_name_t *name,
      const dns_rdata_nsec3param_t *nsec3param, dns_rdataset_t *rdataset,
      const unsigned char types[8192], unsigned int maxtype,
      const unsigned char *rawhash, size_t rhsize,
      isc_result_t *vresult) {
  unsigned char cbm[8244];
  char namebuf[DNS_NAME_FORMATSIZE];
  dns_rdata_nsec3_t nsec3;
  isc_result_t result;
  unsigned int len;

  result = find_nsec3_match(nsec3param, rdataset, rhsize, &nsec3);
  if (result != ISC_R_SUCCESS) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx, "Missing NSEC3 record for %s",
             namebuf);
    *vresult = result;
    return ISC_R_SUCCESS;
  }

  /*
   * Check the type list.
   */
  len = dns_nsec_compressbitmap(cbm, types, maxtype);
  if (nsec3.len != len || memcmp(cbm, nsec3.typebits, len) != 0) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx,
             "Bad NSEC3 record for %s, bit map "
             "mismatch",
             namebuf);
    *vresult = ISC_R_FAILURE;
    return ISC_R_SUCCESS;
  }

  /*
   * Record chain.
   */
  record_nsec3(vctx, rawhash, &nsec3, vctx->expected_chains);

  /*
   * Make sure there is only one NSEC3 record with this set of
   * parameters.
   */
  for (result = dns_rdataset_next(rdataset); result == ISC_R_SUCCESS;
       result = dns_rdataset_next(rdataset))
  {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &nsec3, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if (nsec3.hash == nsec3param->hash &&
        nsec3.iterations == nsec3param->iterations &&
        nsec3.salt_length == nsec3param->salt_length &&
        memcmp(nsec3.salt, nsec3param->salt, nsec3.salt_length) ==
          0)
    {
      dns_name_format(name, namebuf, sizeof(namebuf));
      zoneverify_log_error(vctx,
               "Multiple NSEC3 records with the "
               "same parameter set for %s",
               namebuf);
      *vresult = DNS_R_DUPLICATE;
      return ISC_R_SUCCESS;
    }
  }
  if (result != ISC_R_NOMORE) {
    return result;
  }

  *vresult = ISC_R_SUCCESS;

  return ISC_R_SUCCESS;
}

static bool
innsec3params(const dns_rdata_nsec3_t *nsec3, dns_rdataset_t *nsec3paramset) {
  dns_rdata_nsec3param_t nsec3param;
  isc_result_t result;

  DNS_RDATASET_FOREACH(nsec3paramset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(nsec3paramset, &rdata);
    result = dns_rdata_tostruct(&rdata, &nsec3param, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if (nsec3param.flags == 0 && nsec3param.hash == nsec3->hash &&
        nsec3param.iterations == nsec3->iterations &&
        nsec3param.salt_length == nsec3->salt_length &&
        memcmp(nsec3param.salt, nsec3->salt, nsec3->salt_length) ==
          0)
    {
      return true;
    }
  }
  return false;
}

static isc_result_t
record_found(const vctx_t *vctx, const dns_name_t *name, dns_dbnode_t *node,
       dns_rdataset_t *nsec3paramset) {
  unsigned char owner[NSEC3_MAX_HASH_LENGTH];
  dns_rdata_nsec3_t nsec3;
  dns_rdataset_t rdataset;
  dns_label_t hashlabel;
  isc_buffer_t b;
  isc_result_t result;

  if (nsec3paramset == NULL || !dns_rdataset_isassociated(nsec3paramset))
  {
    return ISC_R_SUCCESS;
  }

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_nsec3, 0, 0, &rdataset,
             NULL);
  if (result != ISC_R_SUCCESS) {
    return ISC_R_SUCCESS;
  }

  dns_name_getlabel(name, 0, &hashlabel);
  isc_region_consume(&hashlabel, 1);
  isc_buffer_init(&b, owner, sizeof(owner));
  result = isc_base32hex_decoderegion(&hashlabel, &b);
  if (result != ISC_R_SUCCESS) {
    result = ISC_R_SUCCESS;
    goto cleanup;
  }

  DNS_RDATASET_FOREACH(&rdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&rdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &nsec3, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if (nsec3.next_length != isc_buffer_usedlength(&b)) {
      continue;
    }

    /*
     * We only care about NSEC3 records that match a NSEC3PARAM
     * record.
     */
    if (!innsec3params(&nsec3, nsec3paramset)) {
      continue;
    }

    /*
     * Record chain.
     */
    record_nsec3(vctx, owner, &nsec3, vctx->found_chains);
  }
  result = ISC_R_SUCCESS;

cleanup:
  dns_rdataset_disassociate(&rdataset);
  return result;
}

static isc_result_t
isoptout(const vctx_t *vctx, const dns_rdata_nsec3param_t *nsec3param,
   bool *optout) {
  dns_rdataset_t rdataset;
  dns_rdata_t rdata = DNS_RDATA_INIT;
  dns_rdata_nsec3_t nsec3;
  dns_fixedname_t fixed;
  dns_name_t *hashname;
  isc_result_t result;
  dns_dbnode_t *node = NULL;
  unsigned char rawhash[NSEC3_MAX_HASH_LENGTH];
  size_t rhsize = sizeof(rawhash);

  dns_fixedname_init(&fixed);
  result = dns_nsec3_hashname(&fixed, rawhash, &rhsize, vctx->origin,
            vctx->origin, nsec3param->hash,
            nsec3param->iterations, nsec3param->salt,
            nsec3param->salt_length);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_nsec3_hashname(): %s",
             isc_result_totext(result));
    return result;
  }

  dns_rdataset_init(&rdataset);
  hashname = dns_fixedname_name(&fixed);
  result = dns_db_findnsec3node(vctx->db, hashname, false, &node);
  if (result == ISC_R_SUCCESS) {
    result = dns_db_findrdataset(vctx->db, node, vctx->ver,
               dns_rdatatype_nsec3, 0, 0,
               &rdataset, NULL);
  }
  if (result != ISC_R_SUCCESS) {
    *optout = false;
    result = ISC_R_SUCCESS;
    goto done;
  }

  result = dns_rdataset_first(&rdataset);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_rdataset_first(): %s",
             isc_result_totext(result));
    goto done;
  }

  dns_rdataset_current(&rdataset, &rdata);

  result = dns_rdata_tostruct(&rdata, &nsec3, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);
  *optout = ((nsec3.flags & DNS_NSEC3FLAG_OPTOUT) != 0);

done:
  if (dns_rdataset_isassociated(&rdataset)) {
    dns_rdataset_disassociate(&rdataset);
  }
  if (node != NULL) {
    dns_db_detachnode(&node);
  }

  return result;
}

static isc_result_t
verifynsec3(const vctx_t *vctx, const dns_name_t *name,
      const dns_rdata_t *rdata, bool delegation, bool empty,
      const unsigned char types[8192], unsigned int maxtype,
      isc_result_t *vresult) {
  char namebuf[DNS_NAME_FORMATSIZE];
  char hashbuf[DNS_NAME_FORMATSIZE];
  dns_rdataset_t rdataset;
  dns_rdata_nsec3param_t nsec3param;
  dns_fixedname_t fixed;
  dns_name_t *hashname;
  isc_result_t result, tvresult = ISC_R_UNSET;
  dns_dbnode_t *node = NULL;
  unsigned char rawhash[NSEC3_MAX_HASH_LENGTH];
  size_t rhsize = sizeof(rawhash);
  bool optout = false;

  result = dns_rdata_tostruct(rdata, &nsec3param, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  if (nsec3param.flags != 0) {
    return ISC_R_SUCCESS;
  }

  if (!dns_nsec3_supportedhash(nsec3param.hash)) {
    return ISC_R_SUCCESS;
  }

  if (nsec3param.iterations > DNS_NSEC3_MAXITERATIONS) {
    result = DNS_R_NSEC3ITERRANGE;
    zoneverify_log_error(vctx, "verifynsec3: %s",
             isc_result_totext(result));
    return result;
  }

  result = isoptout(vctx, &nsec3param, &optout);
  if (result != ISC_R_SUCCESS) {
    return result;
  }

  dns_fixedname_init(&fixed);
  result = dns_nsec3_hashname(
    &fixed, rawhash, &rhsize, name, vctx->origin, nsec3param.hash,
    nsec3param.iterations, nsec3param.salt, nsec3param.salt_length);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_nsec3_hashname(): %s",
             isc_result_totext(result));
    return result;
  }

  /*
   * We don't use dns_db_find() here as it works with the chosen
   * nsec3 chain and we may also be called with uncommitted data
   * from dnssec-signzone so the secure status of the zone may not
   * be up to date.
   */
  dns_rdataset_init(&rdataset);
  hashname = dns_fixedname_name(&fixed);
  result = dns_db_findnsec3node(vctx->db, hashname, false, &node);
  if (result == ISC_R_SUCCESS) {
    result = dns_db_findrdataset(vctx->db, node, vctx->ver,
               dns_rdatatype_nsec3, 0, 0,
               &rdataset, NULL);
  }
  if (result != ISC_R_SUCCESS &&
      (!delegation || (empty && !optout) ||
       (!empty && dns_nsec_isset(types, dns_rdatatype_ds))))
  {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_name_format(hashname, hashbuf, sizeof(hashbuf));
    zoneverify_log_error(vctx, "Missing NSEC3 record for %s (%s)",
             namebuf, hashbuf);
  } else if (result == ISC_R_NOTFOUND && delegation && (!empty || optout))
  {
    result = ISC_R_SUCCESS;
  } else if (result == ISC_R_SUCCESS) {
    result = match_nsec3(vctx, name, &nsec3param, &rdataset, types,
             maxtype, rawhash, rhsize, &tvresult);
    if (result != ISC_R_SUCCESS) {
      goto done;
    }
    result = tvresult;
  }

  *vresult = result;
  result = ISC_R_SUCCESS;

done:
  if (dns_rdataset_isassociated(&rdataset)) {
    dns_rdataset_disassociate(&rdataset);
  }
  if (node != NULL) {
    dns_db_detachnode(&node);
  }

  return result;
}

static isc_result_t
verifynsec3s(const vctx_t *vctx, const dns_name_t *name,
       dns_rdataset_t *nsec3paramset, bool delegation, bool empty,
       const unsigned char types[8192], unsigned int maxtype,
       isc_result_t *vresult) {
  isc_result_t result = ISC_R_NOMORE;

  DNS_RDATASET_FOREACH(nsec3paramset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;

    dns_rdataset_current(nsec3paramset, &rdata);
    result = verifynsec3(vctx, name, &rdata, delegation, empty,
             types, maxtype, vresult);
    if (result != ISC_R_SUCCESS) {
      return result;
    }
    if (*vresult != ISC_R_SUCCESS) {
      break;
    }
  }

  return result;
}

static isc_result_t
verifyset(vctx_t *vctx, dns_rdataset_t *rdataset, const dns_name_t *name,
    dns_dbnode_t *node, dst_key_t **dstkeys, size_t nkeys) {
  unsigned char set_algorithms[DST_MAX_ALGS] = { 0 };
  char namebuf[DNS_NAME_FORMATSIZE];
  char algbuf[DNS_SECALG_FORMATSIZE];
  char typebuf[DNS_RDATATYPE_FORMATSIZE];
  dns_rdataset_t sigrdataset = DNS_RDATASET_INIT;
  dns_rdatasetiter_t *rdsiter = NULL;
  bool match = false;
  isc_result_t result;

  result = dns_db_allrdatasets(vctx->db, node, vctx->ver, 0, 0, &rdsiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_allrdatasets(): %s",
             isc_result_totext(result));
    return result;
  }
  DNS_RDATASETITER_FOREACH(rdsiter) {
    dns_rdatasetiter_current(rdsiter, &sigrdataset);
    if (sigrdataset.type == dns_rdatatype_rrsig &&
        sigrdataset.covers == rdataset->type)
    {
      match = true;
      break;
    }
    dns_rdataset_disassociate(&sigrdataset);
  }

  if (!match) {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_rdatatype_format(rdataset->type, typebuf, sizeof(typebuf));
    zoneverify_log_error(vctx, "No signatures for %s/%s", namebuf,
             typebuf);
    for (size_t i = 0; i < ARRAY_SIZE(set_algorithms); i++) {
      if (vctx->act_algorithms[i] != 0) {
        vctx->bad_algorithms[i] = 1;
      }
    }
    result = ISC_R_SUCCESS;
    goto done;
  }

  DNS_RDATASET_FOREACH(&sigrdataset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdata_rrsig_t sig;
    dst_algorithm_t algorithm;

    dns_rdataset_current(&sigrdataset, &rdata);
    result = dns_rdata_tostruct(&rdata, &sig, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    if (rdataset->ttl != sig.originalttl) {
      dns_name_format(name, namebuf, sizeof(namebuf));
      dns_rdatatype_format(rdataset->type, typebuf,
               sizeof(typebuf));
      zoneverify_log_error(vctx,
               "TTL mismatch for "
               "%s %s keytag %u",
               namebuf, typebuf, sig.keyid);
      continue;
    }
    algorithm = dst_algorithm_fromdata(sig.algorithm, sig.signature,
               sig.siglen);
    if ((set_algorithms[algorithm] != 0) ||
        (vctx->act_algorithms[algorithm] == 0))
    {
      continue;
    }
    if (goodsig(vctx, &rdata, name, dstkeys, nkeys, rdataset)) {
      dns_rdataset_settrust(rdataset, dns_trust_secure);
      dns_rdataset_settrust(&sigrdataset, dns_trust_secure);
      set_algorithms[algorithm] = 1;
    }
  }
  result = ISC_R_SUCCESS;

  if (memcmp(set_algorithms, vctx->act_algorithms,
       sizeof(set_algorithms)) != 0)
  {
    dns_name_format(name, namebuf, sizeof(namebuf));
    dns_rdatatype_format(rdataset->type, typebuf, sizeof(typebuf));
    for (size_t i = 0; i < ARRAY_SIZE(set_algorithms); i++) {
      if ((vctx->act_algorithms[i] != 0) &&
          (set_algorithms[i] == 0))
      {
        dst_algorithm_format(i, algbuf, sizeof(algbuf));
        zoneverify_log_error(vctx,
                 "No correct %s signature "
                 "for %s %s",
                 algbuf, namebuf, typebuf);
        vctx->bad_algorithms[i] = 1;
      }
    }
  }

done:
  if (dns_rdataset_isassociated(&sigrdataset)) {
    dns_rdataset_disassociate(&sigrdataset);
  }
  dns_rdatasetiter_destroy(&rdsiter);

  return result;
}

static isc_result_t
verifynode(vctx_t *vctx, const dns_name_t *name, dns_dbnode_t *node,
     bool delegation, dst_key_t **dstkeys, size_t nkeys,
     dns_rdataset_t *nsecset, dns_rdataset_t *nsec3paramset,
     const dns_name_t *nextname, isc_result_t *vresult) {
  unsigned char types[8192] = { 0 };
  unsigned int maxtype = 0;
  dns_rdatasetiter_t *rdsiter = NULL;
  isc_result_t result, tvresult = ISC_R_UNSET;

  REQUIRE(vresult != NULL || (nsecset == NULL && nsec3paramset == NULL));

  result = dns_db_allrdatasets(vctx->db, node, vctx->ver, 0, 0, &rdsiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_allrdatasets(): %s",
             isc_result_totext(result));
    return result;
  }

  DNS_RDATASETITER_FOREACH(rdsiter) {
    dns_rdataset_t rdataset = DNS_RDATASET_INIT;
    dns_rdatasetiter_current(rdsiter, &rdataset);

    /*
     * If we are not at a delegation then everything should be
     * signed.  If we are at a delegation then only the DS set
     * is signed.  The NS set is not signed at a delegation but
     * its existence is recorded in the bit map.  Anything else
     * other than NSEC and DS is not signed at a delegation.
     */
    if (rdataset.type != dns_rdatatype_rrsig &&
        (!delegation || rdataset.type == dns_rdatatype_ds ||
         rdataset.type == dns_rdatatype_nsec))
    {
      result = verifyset(vctx, &rdataset, name, node, dstkeys,
             nkeys);
      if (result != ISC_R_SUCCESS) {
        dns_rdataset_disassociate(&rdataset);
        dns_rdatasetiter_destroy(&rdsiter);
        return result;
      }
      dns_nsec_setbit(types, rdataset.type, 1);
      if (rdataset.type > maxtype) {
        maxtype = rdataset.type;
      }
    } else if (rdataset.type != dns_rdatatype_rrsig) {
      if (rdataset.type == dns_rdatatype_ns) {
        dns_nsec_setbit(types, rdataset.type, 1);
        if (rdataset.type > maxtype) {
          maxtype = rdataset.type;
        }
      }
      result = check_no_rrsig(vctx, &rdataset, name, node);
      if (result != ISC_R_SUCCESS) {
        dns_rdataset_disassociate(&rdataset);
        dns_rdatasetiter_destroy(&rdsiter);
        return result;
      }
    } else {
      dns_nsec_setbit(types, rdataset.type, 1);
      if (rdataset.type > maxtype) {
        maxtype = rdataset.type;
      }
    }
    dns_rdataset_disassociate(&rdataset);
  }
  dns_rdatasetiter_destroy(&rdsiter);

  if (vresult == NULL) {
    return ISC_R_SUCCESS;
  }

  *vresult = ISC_R_SUCCESS;

  if (nsecset != NULL && dns_rdataset_isassociated(nsecset)) {
    result = verifynsec(vctx, name, node, nextname, &tvresult);
    if (result != ISC_R_SUCCESS) {
      return result;
    }
    *vresult = tvresult;
  }

  if (nsec3paramset != NULL && dns_rdataset_isassociated(nsec3paramset)) {
    result = verifynsec3s(vctx, name, nsec3paramset, delegation,
              false, types, maxtype, &tvresult);
    if (result != ISC_R_SUCCESS) {
      return result;
    }
    if (*vresult == ISC_R_SUCCESS) {
      *vresult = tvresult;
    }
  }

  return ISC_R_SUCCESS;
}

static isc_result_t
is_empty(const vctx_t *vctx, dns_dbnode_t *node) {
  dns_rdatasetiter_t *rdsiter = NULL;
  isc_result_t result;

  result = dns_db_allrdatasets(vctx->db, node, vctx->ver, 0, 0, &rdsiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_allrdatasets(): %s",
             isc_result_totext(result));
    return result;
  }
  result = dns_rdatasetiter_first(rdsiter);
  dns_rdatasetiter_destroy(&rdsiter);

  return result;
}

static isc_result_t
check_no_nsec(const vctx_t *vctx, const dns_name_t *name, dns_dbnode_t *node) {
  bool nsec_exists = false;
  dns_rdataset_t rdataset;
  isc_result_t result;

  dns_rdataset_init(&rdataset);
  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_nsec, 0, 0, &rdataset, NULL);
  if (result != ISC_R_NOTFOUND) {
    char namebuf[DNS_NAME_FORMATSIZE];
    dns_name_format(name, namebuf, sizeof(namebuf));
    zoneverify_log_error(vctx, "unexpected NSEC RRset at %s",
             namebuf);
    nsec_exists = true;
  }

  if (dns_rdataset_isassociated(&rdataset)) {
    dns_rdataset_disassociate(&rdataset);
  }

  return nsec_exists ? ISC_R_FAILURE : ISC_R_SUCCESS;
}

static void
free_element(isc_mem_t *mctx, struct nsec3_chain_fixed *e) {
  size_t len;

  len = sizeof(*e) + e->salt_length + 2 * e->next_length;
  isc_mem_put(mctx, e, len);
}

static void
free_element_heap(void *element, void *uap) {
  struct nsec3_chain_fixed *e = (struct nsec3_chain_fixed *)element;
  isc_mem_t *mctx = (isc_mem_t *)uap;

  free_element(mctx, e);
}

static bool
_checknext(const vctx_t *vctx, const struct nsec3_chain_fixed *first,
     const struct nsec3_chain_fixed *e) {
  char buf[512];
  const unsigned char *d1 = (const unsigned char *)(first + 1);
  const unsigned char *d2 = (const unsigned char *)(e + 1);
  isc_buffer_t b;
  isc_region_t sr;

  d1 += first->salt_length + first->next_length;
  d2 += e->salt_length;

  if (memcmp(d1, d2, first->next_length) == 0) {
    return true;
  }

  sr.base = UNCONST(d1 - first->next_length);
  sr.length = first->next_length;
  isc_buffer_init(&b, buf, sizeof(buf));
  isc_base32hex_totext(&sr, 1, "", &b);
  zoneverify_log_error(vctx, "Break in NSEC3 chain at: %.*s",
           (int)isc_buffer_usedlength(&b), buf);

  sr.base = UNCONST(d1);
  sr.length = first->next_length;
  isc_buffer_init(&b, buf, sizeof(buf));
  isc_base32hex_totext(&sr, 1, "", &b);
  zoneverify_log_error(vctx, "Expected: %.*s",
           (int)isc_buffer_usedlength(&b), buf);

  sr.base = UNCONST(d2);
  sr.length = first->next_length;
  isc_buffer_init(&b, buf, sizeof(buf));
  isc_base32hex_totext(&sr, 1, "", &b);
  zoneverify_log_error(vctx, "Found: %.*s",
           (int)isc_buffer_usedlength(&b), buf);

  return false;
}

static bool
checknext(isc_mem_t *mctx, const vctx_t *vctx,
    const struct nsec3_chain_fixed *first, struct nsec3_chain_fixed *prev,
    const struct nsec3_chain_fixed *cur) {
  bool result = _checknext(vctx, prev, cur);

  if (prev != first) {
    free_element(mctx, prev);
  }

  return result;
}

static bool
checklast(isc_mem_t *mctx, const vctx_t *vctx, struct nsec3_chain_fixed *first,
    struct nsec3_chain_fixed *prev) {
  bool result = _checknext(vctx, prev, first);
  if (prev != first) {
    free_element(mctx, prev);
  }
  free_element(mctx, first);

  return result;
}

static isc_result_t
verify_nsec3_chains(const vctx_t *vctx, isc_mem_t *mctx) {
  isc_result_t result = ISC_R_SUCCESS;
  struct nsec3_chain_fixed *e, *f = NULL;
  struct nsec3_chain_fixed *first = NULL, *prev = NULL;

  while ((e = isc_heap_element(vctx->expected_chains, 1)) != NULL) {
    isc_heap_delete(vctx->expected_chains, 1);
    if (f == NULL) {
      f = isc_heap_element(vctx->found_chains, 1);
    }
    if (f != NULL) {
      isc_heap_delete(vctx->found_chains, 1);

      /*
       * Check that they match.
       */
      if (chain_equal(e, f, chain_length(e))) {
        free_element(mctx, f);
        f = NULL;
      } else {
        if (result == ISC_R_SUCCESS) {
          zoneverify_log_error(vctx, "Expected "
                   "and found "
                   "NSEC3 "
                   "chains not "
                   "equal");
        }
        result = ISC_R_FAILURE;
        /*
         * Attempt to resync found_chain.
         */
        while (f != NULL && !chain_compare(e, f)) {
          free_element(mctx, f);
          f = isc_heap_element(vctx->found_chains,
                   1);
          if (f != NULL) {
            isc_heap_delete(
              vctx->found_chains, 1);
          }
          if (f != NULL &&
              chain_equal(e, f, chain_length(e)))
          {
            free_element(mctx, f);
            f = NULL;
            break;
          }
        }
      }
    } else if (result == ISC_R_SUCCESS) {
      zoneverify_log_error(vctx, "Expected and found NSEC3 "
               "chains "
               "not equal");
      result = ISC_R_FAILURE;
    }

    if (first == NULL) {
      prev = first = e;
    } else if (!chain_equal(first, e, first->salt_length)) {
      if (!checklast(mctx, vctx, first, prev)) {
        result = ISC_R_FAILURE;
      }

      prev = first = e;
    } else {
      if (!checknext(mctx, vctx, first, prev, e)) {
        result = ISC_R_FAILURE;
      }

      prev = e;
    }
  }
  if (prev != NULL) {
    if (!checklast(mctx, vctx, first, prev)) {
      result = ISC_R_FAILURE;
    }
  }
  do {
    if (f != NULL) {
      if (result == ISC_R_SUCCESS) {
        zoneverify_log_error(vctx, "Expected and found "
                 "NSEC3 chains not "
                 "equal");
        result = ISC_R_FAILURE;
      }
      free_element(mctx, f);
    }
    f = isc_heap_element(vctx->found_chains, 1);
    if (f != NULL) {
      isc_heap_delete(vctx->found_chains, 1);
    }
  } while (f != NULL);

  return result;
}

static isc_result_t
verifyemptynodes(const vctx_t *vctx, const dns_name_t *name,
     const dns_name_t *prevname, bool isdelegation,
     dns_rdataset_t *nsec3paramset, isc_result_t *vresult) {
  dns_namereln_t reln;
  int order;
  unsigned int labels, nlabels, i;
  dns_name_t suffix;
  isc_result_t result, tvresult = ISC_R_UNSET;

  *vresult = ISC_R_SUCCESS;

  reln = dns_name_fullcompare(prevname, name, &order, &labels);
  if (order >= 0) {
    return ISC_R_SUCCESS;
  }

  nlabels = dns_name_countlabels(name);

  if (reln == dns_namereln_commonancestor ||
      reln == dns_namereln_contains)
  {
    dns_name_init(&suffix);
    for (i = labels + 1; i < nlabels; i++) {
      dns_name_getlabelsequence(name, nlabels - i, i,
              &suffix);
      if (nsec3paramset != NULL &&
          dns_rdataset_isassociated(nsec3paramset))
      {
        result = verifynsec3s(
          vctx, &suffix, nsec3paramset,
          isdelegation, true, NULL, 0, &tvresult);
        if (result != ISC_R_SUCCESS) {
          return result;
        }
        if (*vresult == ISC_R_SUCCESS) {
          *vresult = tvresult;
        }
      }
    }
  }

  return ISC_R_SUCCESS;
}

static void
vctx_init(vctx_t *vctx, isc_mem_t *mctx, dns_zone_t *zone, dns_db_t *db,
    dns_dbversion_t *ver, dns_name_t *origin, dns_keytable_t *secroots) {
  memset(vctx, 0, sizeof(*vctx));

  vctx->mctx = mctx;
  vctx->zone = zone;
  vctx->db = db;
  vctx->ver = ver;
  vctx->origin = origin;
  vctx->secroots = secroots;
  vctx->goodksk = false;
  vctx->goodzsk = false;

  dns_rdataset_init(&vctx->keyset);
  dns_rdataset_init(&vctx->keysigs);
  dns_rdataset_init(&vctx->soaset);
  dns_rdataset_init(&vctx->soasigs);
  dns_rdataset_init(&vctx->nsecset);
  dns_rdataset_init(&vctx->nsecsigs);
  dns_rdataset_init(&vctx->nsec3paramset);
  dns_rdataset_init(&vctx->nsec3paramsigs);

  vctx->expected_chains = NULL;
  isc_heap_create(mctx, chain_compare, NULL, 1024,
      &vctx->expected_chains);

  vctx->found_chains = NULL;
  isc_heap_create(mctx, chain_compare, NULL, 1024, &vctx->found_chains);
}

static void
vctx_destroy(vctx_t *vctx) {
  if (dns_rdataset_isassociated(&vctx->keyset)) {
    dns_rdataset_disassociate(&vctx->keyset);
  }
  if (dns_rdataset_isassociated(&vctx->keysigs)) {
    dns_rdataset_disassociate(&vctx->keysigs);
  }
  if (dns_rdataset_isassociated(&vctx->soaset)) {
    dns_rdataset_disassociate(&vctx->soaset);
  }
  if (dns_rdataset_isassociated(&vctx->soasigs)) {
    dns_rdataset_disassociate(&vctx->soasigs);
  }
  if (dns_rdataset_isassociated(&vctx->nsecset)) {
    dns_rdataset_disassociate(&vctx->nsecset);
  }
  if (dns_rdataset_isassociated(&vctx->nsecsigs)) {
    dns_rdataset_disassociate(&vctx->nsecsigs);
  }
  if (dns_rdataset_isassociated(&vctx->nsec3paramset)) {
    dns_rdataset_disassociate(&vctx->nsec3paramset);
  }
  if (dns_rdataset_isassociated(&vctx->nsec3paramsigs)) {
    dns_rdataset_disassociate(&vctx->nsec3paramsigs);
  }
  isc_heap_foreach(vctx->expected_chains, free_element_heap, vctx->mctx);
  isc_heap_destroy(&vctx->expected_chains);
  isc_heap_foreach(vctx->found_chains, free_element_heap, vctx->mctx);
  isc_heap_destroy(&vctx->found_chains);
}

static isc_result_t
check_apex_rrsets(vctx_t *vctx) {
  dns_dbnode_t *node = NULL;
  isc_result_t result;

  result = dns_db_findnode(vctx->db, vctx->origin, false, &node);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx,
             "failed to find the zone's origin: %s",
             isc_result_totext(result));
    return result;
  }

  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_dnskey, 0, 0, &vctx->keyset,
             &vctx->keysigs);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "Zone contains no DNSSEC keys");
    goto done;
  }

  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_soa, 0, 0, &vctx->soaset,
             &vctx->soasigs);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "Zone contains no SOA record");
    goto done;
  }

  result = dns_db_findrdataset(vctx->db, node, vctx->ver,
             dns_rdatatype_nsec, 0, 0, &vctx->nsecset,
             &vctx->nsecsigs);
  if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
    zoneverify_log_error(vctx, "NSEC lookup failed");
    goto done;
  }

  result = dns_db_findrdataset(
    vctx->db, node, vctx->ver, dns_rdatatype_nsec3param, 0, 0,
    &vctx->nsec3paramset, &vctx->nsec3paramsigs);
  if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
    zoneverify_log_error(vctx, "NSEC3PARAM lookup failed");
    goto done;
  }

  if (!dns_rdataset_isassociated(&vctx->keysigs)) {
    zoneverify_log_error(vctx, "DNSKEY is not signed "
             "(keys offline or inactive?)");
    result = ISC_R_FAILURE;
    goto done;
  }

  if (!dns_rdataset_isassociated(&vctx->soasigs)) {
    zoneverify_log_error(vctx, "SOA is not signed "
             "(keys offline or inactive?)");
    result = ISC_R_FAILURE;
    goto done;
  }

  if (dns_rdataset_isassociated(&vctx->nsecset) &&
      !dns_rdataset_isassociated(&vctx->nsecsigs))
  {
    zoneverify_log_error(vctx, "NSEC is not signed "
             "(keys offline or inactive?)");
    result = ISC_R_FAILURE;
    goto done;
  }

  if (dns_rdataset_isassociated(&vctx->nsec3paramset) &&
      !dns_rdataset_isassociated(&vctx->nsec3paramsigs))
  {
    zoneverify_log_error(vctx, "NSEC3PARAM is not signed "
             "(keys offline or inactive?)");
    result = ISC_R_FAILURE;
    goto done;
  }

  if (!dns_rdataset_isassociated(&vctx->nsecset) &&
      !dns_rdataset_isassociated(&vctx->nsec3paramset))
  {
    zoneverify_log_error(vctx, "No valid NSEC/NSEC3 chain for "
             "testing");
    result = ISC_R_FAILURE;
    goto done;
  }

  result = ISC_R_SUCCESS;

done:
  dns_db_detachnode(&node);

  return result;
}

/*%
 * Update 'vctx' tables tracking active and standby key algorithms used in the
 * verified zone based on the signatures made using 'dnskey' (prepared from
 * 'rdata') found at zone apex.  Set 'vctx->goodksk' or 'vctx->goodzsk' to true
 * if 'dnskey' correctly signs the DNSKEY RRset at zone apex and either
 * 'vctx->secroots' is NULL or 'dnskey' is present in 'vctx->secroots'.
 *
 * The variables to update are chosen based on 'is_ksk', which is true when
 * 'dnskey' is a KSK and false otherwise.
 */
static void
check_dnskey_sigs(vctx_t *vctx, const dns_rdata_dnskey_t *dnskey,
      dns_rdata_t *keyrdata, bool is_ksk) {
  unsigned char *active_keys = NULL, *standby_keys = NULL;
  dns_keynode_t *keynode = NULL;
  bool *goodkey = NULL;
  dst_key_t *key = NULL;
  isc_result_t result;
  dns_rdataset_t dsset;
  dst_algorithm_t algorithm;

  active_keys = (is_ksk ? vctx->ksk_algorithms : vctx->zsk_algorithms);
  standby_keys = (is_ksk ? vctx->standby_ksk : vctx->standby_zsk);
  goodkey = (is_ksk ? &vctx->goodksk : &vctx->goodzsk);
  algorithm = dst_algorithm_fromdata(dnskey->algorithm, dnskey->data,
             dnskey->datalen);

  /*
   * First, does this key sign the DNSKEY rrset?
   */
  if (!dns_dnssec_selfsigns(keyrdata, vctx->origin, &vctx->keyset,
          &vctx->keysigs, false, vctx->mctx))
  {
    if (!is_ksk &&
        dns_dnssec_signs(keyrdata, vctx->origin, &vctx->soaset,
             &vctx->soasigs, false, vctx->mctx))
    {
      if (active_keys[algorithm] != DNS_KEYALG_MAX) {
        active_keys[algorithm]++;
      }
    } else {
      if (standby_keys[algorithm] != DNS_KEYALG_MAX) {
        standby_keys[algorithm]++;
      }
    }
    return;
  }

  if (active_keys[algorithm] != DNS_KEYALG_MAX) {
    active_keys[algorithm]++;
  }

  /*
   * If a trust anchor table was not supplied, a correctly self-signed
   * DNSKEY RRset is good enough.
   */
  if (vctx->secroots == NULL) {
    *goodkey = true;
    return;
  }

  /*
   * Convert the supplied key rdata to dst_key_t. (If this
   * fails we can't go further.)
   */
  result = dns_dnssec_keyfromrdata(vctx->origin, keyrdata, vctx->mctx,
           &key);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  /*
   * Look up the supplied key in the trust anchor table.
   * If we don't find an exact match, or if the keynode data
   * is NULL, then we have neither a DNSKEY nor a DS format
   * trust anchor, and can give up.
   */
  result = dns_keytable_find(vctx->secroots, vctx->origin, &keynode);
  if (result != ISC_R_SUCCESS) {
    /* No such trust anchor */
    goto cleanup;
  }

  /*
   * If the keynode has any DS format trust anchors, that means
   * it doesn't have any DNSKEY ones. So, we can check for a DS
   * match and then stop.
   */
  dns_rdataset_init(&dsset);
  if (dns_keynode_dsset(keynode, &dsset)) {
    DNS_RDATASET_FOREACH(&dsset) {
      dns_rdata_t dsrdata = DNS_RDATA_INIT;
      dns_rdata_t newdsrdata = DNS_RDATA_INIT;
      unsigned char buf[DNS_DS_BUFFERSIZE];
      dns_rdata_ds_t ds;

      dns_rdata_reset(&dsrdata);
      dns_rdataset_current(&dsset, &dsrdata);
      result = dns_rdata_tostruct(&dsrdata, &ds, NULL);
      RUNTIME_CHECK(result == ISC_R_SUCCESS);

      if (ds.key_tag != dst_key_id(key) ||
          ds.algorithm !=
            dst_algorithm_tosecalg(dst_key_alg(key)))
      {
        continue;
      }

      result = dns_ds_buildrdata(vctx->origin, keyrdata,
               ds.digest_type, buf,
               sizeof(buf), &newdsrdata);
      if (result != ISC_R_SUCCESS) {
        continue;
      }

      if (dns_rdata_compare(&dsrdata, &newdsrdata) == 0) {
        dns_rdataset_settrust(&vctx->keyset,
                  dns_trust_secure);
        dns_rdataset_settrust(&vctx->keysigs,
                  dns_trust_secure);
        *goodkey = true;
        break;
      }
    }
    dns_rdataset_disassociate(&dsset);

    goto cleanup;
  }

cleanup:
  if (keynode != NULL) {
    dns_keynode_detach(&keynode);
  }
  if (key != NULL) {
    dst_key_free(&key);
  }
}

/*%
 * Check that the DNSKEY RR has at least one self signing KSK and one ZSK per
 * algorithm in it (or, if -x was used, one self-signing KSK).
 */
static isc_result_t
check_dnskey(vctx_t *vctx) {
  dns_rdata_dnskey_t dnskey;
  isc_result_t result;
  bool is_ksk;

  DNS_RDATASET_FOREACH(&vctx->keyset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&vctx->keyset, &rdata);
    result = dns_rdata_tostruct(&rdata, &dnskey, NULL);
    RUNTIME_CHECK(result == ISC_R_SUCCESS);
    is_ksk = ((dnskey.flags & DNS_KEYFLAG_KSK) != 0);

    if ((dnskey.flags & DNS_KEYOWNER_ZONE) != 0 &&
        (dnskey.flags & DNS_KEYFLAG_REVOKE) != 0)
    {
      dst_algorithm_t algorithm;
      if ((dnskey.flags & DNS_KEYFLAG_KSK) != 0 &&
          !dns_dnssec_selfsigns(&rdata, vctx->origin,
              &vctx->keyset, &vctx->keysigs,
              false, vctx->mctx))
      {
        char namebuf[DNS_NAME_FORMATSIZE];
        char buffer[1024];
        isc_buffer_t buf;

        dns_name_format(vctx->origin, namebuf,
            sizeof(namebuf));
        isc_buffer_init(&buf, buffer, sizeof(buffer));
        result = dns_rdata_totext(&rdata, NULL, &buf);
        if (result != ISC_R_SUCCESS) {
          zoneverify_log_error(
            vctx, "dns_rdata_totext: %s",
            isc_result_totext(result));
          return ISC_R_FAILURE;
        }
        zoneverify_log_error(
          vctx,
          "revoked KSK is not self signed:\n"
          "%s DNSKEY %.*s",
          namebuf,
          (int)isc_buffer_usedlength(&buf),
          buffer);
        return ISC_R_FAILURE;
      }
      algorithm = dst_algorithm_fromdata(
        dnskey.algorithm, dnskey.data, dnskey.datalen);
      if ((dnskey.flags & DNS_KEYFLAG_KSK) != 0 &&
          vctx->revoked_ksk[algorithm] != DNS_KEYALG_MAX)
      {
        vctx->revoked_ksk[algorithm]++;
      } else if ((dnskey.flags & DNS_KEYFLAG_KSK) == 0 &&
           vctx->revoked_zsk[algorithm] !=
             DNS_KEYALG_MAX)
      {
        vctx->revoked_zsk[algorithm]++;
      }
    } else {
      check_dnskey_sigs(vctx, &dnskey, &rdata, is_ksk);
    }
    dns_rdata_freestruct(&dnskey);
  }

  return ISC_R_SUCCESS;
}

static void
determine_active_algorithms(vctx_t *vctx, bool ignore_kskflag,
          bool keyset_kskonly,
          void (*report)(const char *, ...)) {
  char algbuf[DNS_SECALG_FORMATSIZE];

  report("Verifying the zone using the following algorithms:");

  for (size_t i = 0; i < ARRAY_SIZE(vctx->act_algorithms); i++) {
    if (ignore_kskflag) {
      vctx->act_algorithms[i] = (vctx->ksk_algorithms[i] !=
                 0 ||
               vctx->zsk_algorithms[i] != 0)
                ? 1
                : 0;
    } else {
      vctx->act_algorithms[i] = vctx->ksk_algorithms[i] != 0
                ? 1
                : 0;
    }
    if (vctx->act_algorithms[i] != 0) {
      dst_algorithm_format(i, algbuf, sizeof(algbuf));
      report("- %s", algbuf);
    }
  }

  if (ignore_kskflag || keyset_kskonly) {
    return;
  }

  for (size_t i = 0; i < ARRAY_SIZE(vctx->ksk_algorithms); i++) {
    /*
     * The counts should both be zero or both be non-zero.  Mark
     * the algorithm as bad if this is not met.
     */
    if ((vctx->ksk_algorithms[i] != 0) ==
        (vctx->zsk_algorithms[i] != 0))
    {
      continue;
    }
    dst_algorithm_format(i, algbuf, sizeof(algbuf));
    zoneverify_log_error(vctx, "Missing %s for algorithm %s",
             (vctx->ksk_algorithms[i] != 0) ? "ZSK"
                    : "self-"
                      "signed "
                      "KSK",
             algbuf);
    vctx->bad_algorithms[i] = 1;
  }
}

/*%
 * Check that all the records not yet verified were signed by keys that are
 * present in the DNSKEY RRset.
 */
static isc_result_t
verify_nodes(vctx_t *vctx, isc_result_t *vresult) {
  dns_fixedname_t fname, fnextname, fprevname, fzonecut;
  dns_name_t *name, *nextname, *prevname, *zonecut;
  dns_dbnode_t *node = NULL, *nextnode;
  dns_dbiterator_t *dbiter = NULL;
  dst_key_t **dstkeys;
  size_t count, nkeys = 0;
  bool done = false;
  isc_result_t tvresult = ISC_R_UNSET;
  isc_result_t result;

  name = dns_fixedname_initname(&fname);
  nextname = dns_fixedname_initname(&fnextname);
  dns_fixedname_init(&fprevname);
  prevname = NULL;
  dns_fixedname_init(&fzonecut);
  zonecut = NULL;

  count = dns_rdataset_count(&vctx->keyset);
  dstkeys = isc_mem_cget(vctx->mctx, count, sizeof(*dstkeys));

  DNS_RDATASET_FOREACH(&vctx->keyset) {
    dns_rdata_t rdata = DNS_RDATA_INIT;
    dns_rdataset_current(&vctx->keyset, &rdata);
    dstkeys[nkeys] = NULL;
    result = dns_dnssec_keyfromrdata(vctx->origin, &rdata,
             vctx->mctx, &dstkeys[nkeys]);
    if (result == ISC_R_SUCCESS) {
      nkeys++;
    }
  }

  result = dns_db_createiterator(vctx->db, DNS_DB_NONSEC3, &dbiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_createiterator(): %s",
             isc_result_totext(result));
    goto done;
  }

  result = dns_dbiterator_first(dbiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_dbiterator_first(): %s",
             isc_result_totext(result));
    goto done;
  }

  while (!done) {
    bool isdelegation = false;

    result = dns_dbiterator_current(dbiter, &node, name);
    if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
      zoneverify_log_error(vctx,
               "dns_dbiterator_current(): %s",
               isc_result_totext(result));
      goto done;
    }
    if (!dns_name_issubdomain(name, vctx->origin)) {
      result = check_no_nsec(vctx, name, node);
      if (result != ISC_R_SUCCESS) {
        dns_db_detachnode(&node);
        goto done;
      }
      dns_db_detachnode(&node);
      result = dns_dbiterator_next(dbiter);
      if (result == ISC_R_NOMORE) {
        done = true;
      } else if (result != ISC_R_SUCCESS) {
        zoneverify_log_error(vctx,
                 "dns_dbiterator_next(): "
                 "%s",
                 isc_result_totext(result));
        goto done;
      }
      continue;
    }
    if (is_delegation(vctx, name, node, NULL)) {
      zonecut = dns_fixedname_name(&fzonecut);
      dns_name_copy(name, zonecut);
      isdelegation = true;
    } else if (has_dname(vctx, node)) {
      zonecut = dns_fixedname_name(&fzonecut);
      dns_name_copy(name, zonecut);
    }
    nextnode = NULL;
    result = dns_dbiterator_next(dbiter);
    while (result == ISC_R_SUCCESS) {
      result = dns_dbiterator_current(dbiter, &nextnode,
              nextname);
      if (result != ISC_R_SUCCESS &&
          result != DNS_R_NEWORIGIN)
      {
        zoneverify_log_error(vctx,
                 "dns_dbiterator_current():"
                 " %s",
                 isc_result_totext(result));
        dns_db_detachnode(&node);
        goto done;
      }
      if (!dns_name_issubdomain(nextname, vctx->origin) ||
          (zonecut != NULL &&
           dns_name_issubdomain(nextname, zonecut)))
      {
        result = check_no_nsec(vctx, nextname,
                   nextnode);
        if (result != ISC_R_SUCCESS) {
          dns_db_detachnode(&node);
          dns_db_detachnode(&nextnode);
          goto done;
        }
        dns_db_detachnode(&nextnode);
        result = dns_dbiterator_next(dbiter);
        continue;
      }
      result = is_empty(vctx, nextnode);
      dns_db_detachnode(&nextnode);
      switch (result) {
      case ISC_R_SUCCESS:
        break;
      case ISC_R_NOMORE:
        result = dns_dbiterator_next(dbiter);
        continue;
      default:
        dns_db_detachnode(&node);
      }
      break;
    }
    if (result == ISC_R_NOMORE) {
      done = true;
      nextname = vctx->origin;
    } else if (result != ISC_R_SUCCESS) {
      zoneverify_log_error(vctx,
               "iterating through the database "
               "failed: %s",
               isc_result_totext(result));
      dns_db_detachnode(&node);
      goto done;
    }
    result = verifynode(vctx, name, node, isdelegation, dstkeys,
            nkeys, &vctx->nsecset, &vctx->nsec3paramset,
            nextname, &tvresult);
    if (result != ISC_R_SUCCESS) {
      dns_db_detachnode(&node);
      goto done;
    }
    if (*vresult == ISC_R_UNSET) {
      *vresult = ISC_R_SUCCESS;
    }
    if (*vresult == ISC_R_SUCCESS) {
      *vresult = tvresult;
    }
    if (prevname != NULL) {
      result = verifyemptynodes(
        vctx, name, prevname, isdelegation,
        &vctx->nsec3paramset, &tvresult);
      if (result != ISC_R_SUCCESS) {
        dns_db_detachnode(&node);
        goto done;
      }
    } else {
      prevname = dns_fixedname_name(&fprevname);
    }
    dns_name_copy(name, prevname);
    if (*vresult == ISC_R_SUCCESS) {
      *vresult = tvresult;
    }
    dns_db_detachnode(&node);
  }

  dns_dbiterator_destroy(&dbiter);

  result = dns_db_createiterator(vctx->db, DNS_DB_NSEC3ONLY, &dbiter);
  if (result != ISC_R_SUCCESS) {
    zoneverify_log_error(vctx, "dns_db_createiterator(): %s",
             isc_result_totext(result));
    return result;
  }

  DNS_DBITERATOR_FOREACH(dbiter) {
    result = dns_dbiterator_current(dbiter, &node, name);
    if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
      zoneverify_log_error(vctx,
               "dns_dbiterator_current(): %s",
               isc_result_totext(result));
      goto done;
    }
    result = verifynode(vctx, name, node, false, dstkeys, nkeys,
            NULL, NULL, NULL, NULL);
    if (result != ISC_R_SUCCESS) {
      zoneverify_log_error(vctx, "verifynode: %s",
               isc_result_totext(result));
      dns_db_detachnode(&node);
      goto done;
    }
    result = record_found(vctx, name, node, &vctx->nsec3paramset);
    dns_db_detachnode(&node);
    if (result != ISC_R_SUCCESS) {
      goto done;
    }
  }

  result = ISC_R_SUCCESS;

done:
  while (nkeys-- > 0U) {
    dst_key_free(&dstkeys[nkeys]);
  }
  isc_mem_cput(vctx->mctx, dstkeys, count, sizeof(*dstkeys));
  if (dbiter != NULL) {
    dns_dbiterator_destroy(&dbiter);
  }

  return result;
}

static isc_result_t
check_bad_algorithms(const vctx_t *vctx, void (*report)(const char *, ...)) {
  char algbuf[DNS_SECALG_FORMATSIZE];
  bool first = true;

  for (size_t i = 0; i < ARRAY_SIZE(vctx->bad_algorithms); i++) {
    if (vctx->bad_algorithms[i] == 0) {
      continue;
    }
    if (first) {
      report("The zone is not fully signed "
             "for the following algorithms:");
    }
    dst_algorithm_format(i, algbuf, sizeof(algbuf));
    report(" %s", algbuf);
    first = false;
  }

  if (!first) {
    report(".");
  }

  return first ? ISC_R_SUCCESS : ISC_R_FAILURE;
}

static void
print_summary(const vctx_t *vctx, bool keyset_kskonly,
        void (*report)(const char *, ...)) {
  char algbuf[DNS_SECALG_FORMATSIZE];

  report("Zone fully signed:");
  for (size_t i = 0; i < ARRAY_SIZE(vctx->ksk_algorithms); i++) {
    if ((vctx->ksk_algorithms[i] == 0) &&
        (vctx->standby_ksk[i] == 0) &&
        (vctx->revoked_ksk[i] == 0) &&
        (vctx->zsk_algorithms[i] == 0) &&
        (vctx->standby_zsk[i] == 0) && (vctx->revoked_zsk[i] == 0))
    {
      continue;
    }
    dst_algorithm_format(i, algbuf, sizeof(algbuf));
    report("Algorithm: %s: KSKs: "
           "%u active, %u stand-by, %u revoked",
           algbuf, vctx->ksk_algorithms[i], vctx->standby_ksk[i],
           vctx->revoked_ksk[i]);
    report("%*sZSKs: "
           "%u active, %u %s, %u revoked",
           (int)strlen(algbuf) + 13, "", vctx->zsk_algorithms[i],
           vctx->standby_zsk[i],
           keyset_kskonly ? "present" : "stand-by",
           vctx->revoked_zsk[i]);
  }
}

isc_result_t
dns_zoneverify_dnssec(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
          dns_name_t *origin, dns_keytable_t *secroots,
          isc_mem_t *mctx, bool ignore_kskflag, bool keyset_kskonly,
          void (*report)(const char *, ...)) {
  const char *keydesc = (secroots == NULL ? "self-signed" : "trusted");
  isc_result_t result, vresult = ISC_R_UNSET;
  vctx_t vctx;

  vctx_init(&vctx, mctx, zone, db, ver, origin, secroots);

  result = check_apex_rrsets(&vctx);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  result = check_dnskey(&vctx);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  if (ignore_kskflag) {
    if (!vctx.goodksk && !vctx.goodzsk) {
      zoneverify_log_error(&vctx, "No %s DNSKEY found",
               keydesc);
      result = ISC_R_FAILURE;
      goto done;
    }
  } else if (!vctx.goodksk) {
    zoneverify_log_error(&vctx, "No %s KSK DNSKEY found", keydesc);
    result = ISC_R_FAILURE;
    goto done;
  }

  determine_active_algorithms(&vctx, ignore_kskflag, keyset_kskonly,
            report);

  result = verify_nodes(&vctx, &vresult);
  if (result != ISC_R_SUCCESS) {
    goto done;
  }

  result = verify_nsec3_chains(&vctx, mctx);
  if (vresult == ISC_R_UNSET) {
    vresult = ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS && vresult == ISC_R_SUCCESS) {
    vresult = result;
  }

  result = check_bad_algorithms(&vctx, report);
  if (result != ISC_R_SUCCESS) {
    report("DNSSEC completeness test failed.");
    goto done;
  }

  result = vresult;
  if (result != ISC_R_SUCCESS) {
    report("DNSSEC completeness test failed (%s).",
           isc_result_totext(result));
    goto done;
  }

  if (vctx.goodksk || ignore_kskflag) {
    print_summary(&vctx, keyset_kskonly, report);
  }

done:
  vctx_destroy(&vctx);

  return result;
}

Coverage Report

Created: 2025-11-09 06:44