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-rw-r--r--lib/dns/validator.c3394
1 files changed, 3394 insertions, 0 deletions
diff --git a/lib/dns/validator.c b/lib/dns/validator.c
new file mode 100644
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--- /dev/null
+++ b/lib/dns/validator.c
@@ -0,0 +1,3394 @@
+/*
+ * 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.
+ */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/base32.h>
+#include <isc/md.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/task.h>
+#include <isc/util.h>
+
+#include <dns/client.h>
+#include <dns/db.h>
+#include <dns/dnssec.h>
+#include <dns/ds.h>
+#include <dns/events.h>
+#include <dns/keytable.h>
+#include <dns/keyvalues.h>
+#include <dns/log.h>
+#include <dns/message.h>
+#include <dns/ncache.h>
+#include <dns/nsec.h>
+#include <dns/nsec3.h>
+#include <dns/rdata.h>
+#include <dns/rdataset.h>
+#include <dns/rdatatype.h>
+#include <dns/resolver.h>
+#include <dns/validator.h>
+#include <dns/view.h>
+
+/*! \file
+ * \brief
+ * Basic processing sequences:
+ *
+ * \li When called with rdataset and sigrdataset:
+ * validator_start -> validate_answer -> proveunsecure
+ * validator_start -> validate_answer -> validate_nx (if secure wildcard)
+ *
+ * \li When called with rdataset but no sigrdataset:
+ * validator_start -> proveunsecure
+ *
+ * \li When called with no rdataset or sigrdataset:
+ * validator_start -> validate_nx-> proveunsecure
+ *
+ * validator_start: determine what type of validation to do.
+ * validate_answer: attempt to perform a positive validation.
+ * proveunsecure: attempt to prove the answer comes from an unsecure zone.
+ * validate_nx: attempt to prove a negative response.
+ */
+
+#define VALIDATOR_MAGIC ISC_MAGIC('V', 'a', 'l', '?')
+#define VALID_VALIDATOR(v) ISC_MAGIC_VALID(v, VALIDATOR_MAGIC)
+
+#define VALATTR_SHUTDOWN 0x0001 /*%< Shutting down. */
+#define VALATTR_CANCELED 0x0002 /*%< Canceled. */
+#define VALATTR_TRIEDVERIFY \
+ 0x0004 /*%< We have found a key and \
+ * have attempted a verify. */
+#define VALATTR_INSECURITY 0x0010 /*%< Attempting proveunsecure. */
+
+/*!
+ * NSEC proofs to be looked for.
+ */
+#define VALATTR_NEEDNOQNAME 0x00000100
+#define VALATTR_NEEDNOWILDCARD 0x00000200
+#define VALATTR_NEEDNODATA 0x00000400
+
+/*!
+ * NSEC proofs that have been found.
+ */
+#define VALATTR_FOUNDNOQNAME 0x00001000
+#define VALATTR_FOUNDNOWILDCARD 0x00002000
+#define VALATTR_FOUNDNODATA 0x00004000
+#define VALATTR_FOUNDCLOSEST 0x00008000
+#define VALATTR_FOUNDOPTOUT 0x00010000
+#define VALATTR_FOUNDUNKNOWN 0x00020000
+
+#define NEEDNODATA(val) ((val->attributes & VALATTR_NEEDNODATA) != 0)
+#define NEEDNOQNAME(val) ((val->attributes & VALATTR_NEEDNOQNAME) != 0)
+#define NEEDNOWILDCARD(val) ((val->attributes & VALATTR_NEEDNOWILDCARD) != 0)
+#define FOUNDNODATA(val) ((val->attributes & VALATTR_FOUNDNODATA) != 0)
+#define FOUNDNOQNAME(val) ((val->attributes & VALATTR_FOUNDNOQNAME) != 0)
+#define FOUNDNOWILDCARD(val) ((val->attributes & VALATTR_FOUNDNOWILDCARD) != 0)
+#define FOUNDCLOSEST(val) ((val->attributes & VALATTR_FOUNDCLOSEST) != 0)
+#define FOUNDOPTOUT(val) ((val->attributes & VALATTR_FOUNDOPTOUT) != 0)
+
+#define SHUTDOWN(v) (((v)->attributes & VALATTR_SHUTDOWN) != 0)
+#define CANCELED(v) (((v)->attributes & VALATTR_CANCELED) != 0)
+
+#define NEGATIVE(r) (((r)->attributes & DNS_RDATASETATTR_NEGATIVE) != 0)
+#define NXDOMAIN(r) (((r)->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0)
+
+static void
+destroy(dns_validator_t *val);
+
+static isc_result_t
+select_signing_key(dns_validator_t *val, dns_rdataset_t *rdataset);
+
+static isc_result_t
+validate_answer(dns_validator_t *val, bool resume);
+
+static isc_result_t
+validate_dnskey(dns_validator_t *val);
+
+static isc_result_t
+validate_nx(dns_validator_t *val, bool resume);
+
+static isc_result_t
+proveunsecure(dns_validator_t *val, bool have_ds, bool resume);
+
+static void
+validator_logv(dns_validator_t *val, isc_logcategory_t *category,
+ isc_logmodule_t *module, int level, const char *fmt, va_list ap)
+ ISC_FORMAT_PRINTF(5, 0);
+
+static void
+validator_log(void *val, int level, const char *fmt, ...)
+ ISC_FORMAT_PRINTF(3, 4);
+
+static void
+validator_logcreate(dns_validator_t *val, dns_name_t *name,
+ dns_rdatatype_t type, const char *caller,
+ const char *operation);
+
+/*%
+ * Ensure the validator's rdatasets are marked as expired.
+ */
+static void
+expire_rdatasets(dns_validator_t *val) {
+ if (dns_rdataset_isassociated(&val->frdataset)) {
+ dns_rdataset_expire(&val->frdataset);
+ }
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ dns_rdataset_expire(&val->fsigrdataset);
+ }
+}
+
+/*%
+ * Ensure the validator's rdatasets are disassociated.
+ */
+static void
+disassociate_rdatasets(dns_validator_t *val) {
+ if (dns_rdataset_isassociated(&val->fdsset)) {
+ dns_rdataset_disassociate(&val->fdsset);
+ }
+ if (dns_rdataset_isassociated(&val->frdataset)) {
+ dns_rdataset_disassociate(&val->frdataset);
+ }
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ dns_rdataset_disassociate(&val->fsigrdataset);
+ }
+}
+
+/*%
+ * Mark the rdatasets in val->event with trust level "answer",
+ * indicating that they did not validate, but could be cached as insecure.
+ *
+ * If we are validating a name that is marked as "must be secure", log a
+ * warning and return DNS_R_MUSTBESECURE instead.
+ */
+static isc_result_t
+markanswer(dns_validator_t *val, const char *where, const char *mbstext) {
+ if (val->mustbesecure && mbstext != NULL) {
+ validator_log(val, ISC_LOG_WARNING,
+ "must be secure failure, %s", mbstext);
+ return (DNS_R_MUSTBESECURE);
+ }
+
+ validator_log(val, ISC_LOG_DEBUG(3), "marking as answer (%s)", where);
+ if (val->event->rdataset != NULL) {
+ dns_rdataset_settrust(val->event->rdataset, dns_trust_answer);
+ }
+ if (val->event->sigrdataset != NULL) {
+ dns_rdataset_settrust(val->event->sigrdataset,
+ dns_trust_answer);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+/*%
+ * Mark the RRsets in val->event with trust level secure.
+ */
+static void
+marksecure(dns_validatorevent_t *event) {
+ dns_rdataset_settrust(event->rdataset, dns_trust_secure);
+ if (event->sigrdataset != NULL) {
+ dns_rdataset_settrust(event->sigrdataset, dns_trust_secure);
+ }
+ event->secure = true;
+}
+
+/*
+ * Validator 'val' is finished; send the completion event to the task
+ * that called dns_validator_create(), with result `result`.
+ */
+static void
+validator_done(dns_validator_t *val, isc_result_t result) {
+ isc_task_t *task;
+
+ if (val->event == NULL) {
+ return;
+ }
+
+ /*
+ * Caller must be holding the lock.
+ */
+
+ val->event->result = result;
+ task = val->event->ev_sender;
+ val->event->ev_sender = val;
+ val->event->ev_type = DNS_EVENT_VALIDATORDONE;
+ val->event->ev_action = val->action;
+ val->event->ev_arg = val->arg;
+ isc_task_sendanddetach(&task, (isc_event_t **)&val->event);
+}
+
+/*
+ * Called when deciding whether to destroy validator 'val'.
+ */
+static bool
+exit_check(dns_validator_t *val) {
+ /*
+ * Caller must be holding the lock.
+ */
+ if (!SHUTDOWN(val)) {
+ return (false);
+ }
+
+ INSIST(val->event == NULL);
+
+ if (val->fetch != NULL || val->subvalidator != NULL) {
+ return (false);
+ }
+
+ return (true);
+}
+
+/*%
+ * Look in the NSEC record returned from a DS query to see if there is
+ * a NS RRset at this name. If it is found we are at a delegation point.
+ */
+static bool
+isdelegation(dns_name_t *name, dns_rdataset_t *rdataset,
+ isc_result_t dbresult) {
+ dns_fixedname_t fixed;
+ dns_label_t hashlabel;
+ dns_name_t nsec3name;
+ dns_rdata_nsec3_t nsec3;
+ dns_rdata_t rdata = DNS_RDATA_INIT;
+ dns_rdataset_t set;
+ int order;
+ int scope;
+ bool found;
+ isc_buffer_t buffer;
+ isc_result_t result;
+ unsigned char hash[NSEC3_MAX_HASH_LENGTH];
+ unsigned char owner[NSEC3_MAX_HASH_LENGTH];
+ unsigned int length;
+
+ REQUIRE(dbresult == DNS_R_NXRRSET || dbresult == DNS_R_NCACHENXRRSET);
+
+ dns_rdataset_init(&set);
+ if (dbresult == DNS_R_NXRRSET) {
+ dns_rdataset_clone(rdataset, &set);
+ } else {
+ result = dns_ncache_getrdataset(rdataset, name,
+ dns_rdatatype_nsec, &set);
+ if (result == ISC_R_NOTFOUND) {
+ goto trynsec3;
+ }
+ if (result != ISC_R_SUCCESS) {
+ return (false);
+ }
+ }
+
+ INSIST(set.type == dns_rdatatype_nsec);
+
+ found = false;
+ result = dns_rdataset_first(&set);
+ if (result == ISC_R_SUCCESS) {
+ dns_rdataset_current(&set, &rdata);
+ found = dns_nsec_typepresent(&rdata, dns_rdatatype_ns);
+ dns_rdata_reset(&rdata);
+ }
+ dns_rdataset_disassociate(&set);
+ return (found);
+
+trynsec3:
+ /*
+ * Iterate over the ncache entry.
+ */
+ found = false;
+ dns_name_init(&nsec3name, NULL);
+ dns_fixedname_init(&fixed);
+ dns_name_downcase(name, dns_fixedname_name(&fixed), NULL);
+ name = dns_fixedname_name(&fixed);
+ for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(rdataset))
+ {
+ dns_ncache_current(rdataset, &nsec3name, &set);
+ if (set.type != dns_rdatatype_nsec3) {
+ dns_rdataset_disassociate(&set);
+ continue;
+ }
+ dns_name_getlabel(&nsec3name, 0, &hashlabel);
+ isc_region_consume(&hashlabel, 1);
+ isc_buffer_init(&buffer, owner, sizeof(owner));
+ result = isc_base32hexnp_decoderegion(&hashlabel, &buffer);
+ if (result != ISC_R_SUCCESS) {
+ dns_rdataset_disassociate(&set);
+ continue;
+ }
+ for (result = dns_rdataset_first(&set); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(&set))
+ {
+ dns_rdata_reset(&rdata);
+ dns_rdataset_current(&set, &rdata);
+ (void)dns_rdata_tostruct(&rdata, &nsec3, NULL);
+ if (nsec3.hash != 1) {
+ continue;
+ }
+ length = isc_iterated_hash(
+ hash, nsec3.hash, nsec3.iterations, nsec3.salt,
+ nsec3.salt_length, name->ndata, name->length);
+ if (length != isc_buffer_usedlength(&buffer)) {
+ continue;
+ }
+ order = memcmp(hash, owner, length);
+ if (order == 0) {
+ found = dns_nsec3_typepresent(&rdata,
+ dns_rdatatype_ns);
+ dns_rdataset_disassociate(&set);
+ return (found);
+ }
+ if ((nsec3.flags & DNS_NSEC3FLAG_OPTOUT) == 0) {
+ continue;
+ }
+ /*
+ * Does this optout span cover the name?
+ */
+ scope = memcmp(owner, nsec3.next, nsec3.next_length);
+ if ((scope < 0 && order > 0 &&
+ memcmp(hash, nsec3.next, length) < 0) ||
+ (scope >= 0 &&
+ (order > 0 ||
+ memcmp(hash, nsec3.next, length) < 0)))
+ {
+ dns_rdataset_disassociate(&set);
+ return (true);
+ }
+ }
+ dns_rdataset_disassociate(&set);
+ }
+ return (found);
+}
+
+/*%
+ * We have been asked to look for a key.
+ * If found, resume the validation process.
+ * If not found, fail the validation process.
+ */
+static void
+fetch_callback_dnskey(isc_task_t *task, isc_event_t *event) {
+ dns_fetchevent_t *devent;
+ dns_validator_t *val;
+ dns_rdataset_t *rdataset;
+ bool want_destroy;
+ isc_result_t result;
+ isc_result_t eresult;
+ isc_result_t saved_result;
+ dns_fetch_t *fetch;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_FETCHDONE);
+ devent = (dns_fetchevent_t *)event;
+ val = devent->ev_arg;
+ rdataset = &val->frdataset;
+ eresult = devent->result;
+
+ /* Free resources which are not of interest. */
+ if (devent->node != NULL) {
+ dns_db_detachnode(devent->db, &devent->node);
+ }
+ if (devent->db != NULL) {
+ dns_db_detach(&devent->db);
+ }
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ dns_rdataset_disassociate(&val->fsigrdataset);
+ }
+ isc_event_free(&event);
+
+ INSIST(val->event != NULL);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in fetch_callback_dnskey");
+ LOCK(&val->lock);
+ fetch = val->fetch;
+ val->fetch = NULL;
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ } else if (eresult == ISC_R_SUCCESS || eresult == DNS_R_NCACHENXRRSET) {
+ /*
+ * We have an answer to our DNSKEY query. Either the DNSKEY
+ * RRset or a NODATA response.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3), "%s with trust %s",
+ eresult == ISC_R_SUCCESS ? "keyset"
+ : "NCACHENXRRSET",
+ dns_trust_totext(rdataset->trust));
+ /*
+ * Only extract the dst key if the keyset exists and is secure.
+ */
+ if (eresult == ISC_R_SUCCESS &&
+ rdataset->trust >= dns_trust_secure)
+ {
+ result = select_signing_key(val, rdataset);
+ if (result == ISC_R_SUCCESS) {
+ val->keyset = &val->frdataset;
+ }
+ }
+ result = validate_answer(val, true);
+ if (result == DNS_R_NOVALIDSIG &&
+ (val->attributes & VALATTR_TRIEDVERIFY) == 0)
+ {
+ saved_result = result;
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "falling back to insecurity proof");
+ result = proveunsecure(val, false, false);
+ if (result == DNS_R_NOTINSECURE) {
+ result = saved_result;
+ }
+ }
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "fetch_callback_dnskey: got %s",
+ isc_result_totext(eresult));
+ if (eresult == ISC_R_CANCELED) {
+ validator_done(val, eresult);
+ } else {
+ validator_done(val, DNS_R_BROKENCHAIN);
+ }
+ }
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+
+ if (fetch != NULL) {
+ dns_resolver_destroyfetch(&fetch);
+ }
+
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+/*%
+ * We have been asked to look for a DS. This may be part of
+ * walking a trust chain, or an insecurity proof.
+ */
+static void
+fetch_callback_ds(isc_task_t *task, isc_event_t *event) {
+ dns_fetchevent_t *devent;
+ dns_validator_t *val;
+ dns_rdataset_t *rdataset;
+ bool want_destroy, trustchain;
+ isc_result_t result;
+ isc_result_t eresult;
+ dns_fetch_t *fetch;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_FETCHDONE);
+ devent = (dns_fetchevent_t *)event;
+ val = devent->ev_arg;
+ rdataset = &val->frdataset;
+ eresult = devent->result;
+
+ /*
+ * Set 'trustchain' to true if we're walking a chain of
+ * trust; false if we're attempting to prove insecurity.
+ */
+ trustchain = ((val->attributes & VALATTR_INSECURITY) == 0);
+
+ /* Free resources which are not of interest. */
+ if (devent->node != NULL) {
+ dns_db_detachnode(devent->db, &devent->node);
+ }
+ if (devent->db != NULL) {
+ dns_db_detach(&devent->db);
+ }
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ dns_rdataset_disassociate(&val->fsigrdataset);
+ }
+
+ INSIST(val->event != NULL);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in fetch_callback_ds");
+ LOCK(&val->lock);
+ fetch = val->fetch;
+ val->fetch = NULL;
+
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ goto done;
+ }
+
+ switch (eresult) {
+ case DNS_R_NXDOMAIN:
+ case DNS_R_NCACHENXDOMAIN:
+ /*
+ * These results only make sense if we're attempting
+ * an insecurity proof, not when walking a chain of trust.
+ */
+ if (trustchain) {
+ goto unexpected;
+ }
+
+ FALLTHROUGH;
+ case ISC_R_SUCCESS:
+ if (trustchain) {
+ /*
+ * We looked for a DS record as part of
+ * following a key chain upwards; resume following
+ * the chain.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "dsset with trust %s",
+ dns_trust_totext(rdataset->trust));
+ val->dsset = &val->frdataset;
+ result = validate_dnskey(val);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else {
+ /*
+ * There is a DS which may or may not be a zone cut.
+ * In either case we are still in a secure zone,
+ * so keep looking for the break in the chain
+ * of trust.
+ */
+ result = proveunsecure(val, (eresult == ISC_R_SUCCESS),
+ true);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ }
+ break;
+ case DNS_R_CNAME:
+ case DNS_R_NXRRSET:
+ case DNS_R_NCACHENXRRSET:
+ case DNS_R_SERVFAIL: /* RFC 1034 parent? */
+ if (trustchain) {
+ /*
+ * Failed to find a DS while following the
+ * chain of trust; now we need to prove insecurity.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "falling back to insecurity proof (%s)",
+ isc_result_totext(eresult));
+ result = proveunsecure(val, false, false);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else if (eresult == DNS_R_SERVFAIL) {
+ goto unexpected;
+ } else if (eresult != DNS_R_CNAME &&
+ isdelegation(devent->foundname, &val->frdataset,
+ eresult))
+ {
+ /*
+ * Failed to find a DS while trying to prove
+ * insecurity. If this is a zone cut, that
+ * means we're insecure.
+ */
+ result = markanswer(val, "fetch_callback_ds",
+ "no DS and this is a delegation");
+ validator_done(val, result);
+ } else {
+ /*
+ * Not a zone cut, so we have to keep looking for
+ * the break point in the chain of trust.
+ */
+ result = proveunsecure(val, false, true);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ }
+ break;
+
+ default:
+ unexpected:
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "fetch_callback_ds: got %s",
+ isc_result_totext(eresult));
+ if (eresult == ISC_R_CANCELED) {
+ validator_done(val, eresult);
+ } else {
+ validator_done(val, DNS_R_BROKENCHAIN);
+ }
+ }
+done:
+
+ isc_event_free(&event);
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+
+ if (fetch != NULL) {
+ dns_resolver_destroyfetch(&fetch);
+ }
+
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+/*%
+ * Callback from when a DNSKEY RRset has been validated.
+ *
+ * Resumes the stalled validation process.
+ */
+static void
+validator_callback_dnskey(isc_task_t *task, isc_event_t *event) {
+ dns_validatorevent_t *devent;
+ dns_validator_t *val;
+ bool want_destroy;
+ isc_result_t result;
+ isc_result_t eresult;
+ isc_result_t saved_result;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);
+
+ devent = (dns_validatorevent_t *)event;
+ val = devent->ev_arg;
+ eresult = devent->result;
+
+ isc_event_free(&event);
+ dns_validator_destroy(&val->subvalidator);
+
+ INSIST(val->event != NULL);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in validator_callback_dnskey");
+ LOCK(&val->lock);
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ } else if (eresult == ISC_R_SUCCESS) {
+ validator_log(val, ISC_LOG_DEBUG(3), "keyset with trust %s",
+ dns_trust_totext(val->frdataset.trust));
+ /*
+ * Only extract the dst key if the keyset is secure.
+ */
+ if (val->frdataset.trust >= dns_trust_secure) {
+ (void)select_signing_key(val, &val->frdataset);
+ }
+ result = validate_answer(val, true);
+ if (result == DNS_R_NOVALIDSIG &&
+ (val->attributes & VALATTR_TRIEDVERIFY) == 0)
+ {
+ saved_result = result;
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "falling back to insecurity proof");
+ result = proveunsecure(val, false, false);
+ if (result == DNS_R_NOTINSECURE) {
+ result = saved_result;
+ }
+ }
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else {
+ if (eresult != DNS_R_BROKENCHAIN) {
+ expire_rdatasets(val);
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "validator_callback_dnskey: got %s",
+ isc_result_totext(eresult));
+ validator_done(val, DNS_R_BROKENCHAIN);
+ }
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+/*%
+ * Callback when the DS record has been validated.
+ *
+ * Resumes validation of the zone key or the unsecure zone proof.
+ */
+static void
+validator_callback_ds(isc_task_t *task, isc_event_t *event) {
+ dns_validatorevent_t *devent;
+ dns_validator_t *val;
+ bool want_destroy;
+ isc_result_t result;
+ isc_result_t eresult;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);
+
+ devent = (dns_validatorevent_t *)event;
+ val = devent->ev_arg;
+ eresult = devent->result;
+
+ isc_event_free(&event);
+ dns_validator_destroy(&val->subvalidator);
+
+ INSIST(val->event != NULL);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in validator_callback_ds");
+ LOCK(&val->lock);
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ } else if (eresult == ISC_R_SUCCESS) {
+ bool have_dsset;
+ dns_name_t *name;
+ validator_log(val, ISC_LOG_DEBUG(3), "%s with trust %s",
+ val->frdataset.type == dns_rdatatype_ds ? "dsset"
+ : "ds "
+ "non-"
+ "existe"
+ "nce",
+ dns_trust_totext(val->frdataset.trust));
+ have_dsset = (val->frdataset.type == dns_rdatatype_ds);
+ name = dns_fixedname_name(&val->fname);
+ if ((val->attributes & VALATTR_INSECURITY) != 0 &&
+ val->frdataset.covers == dns_rdatatype_ds &&
+ NEGATIVE(&val->frdataset) &&
+ isdelegation(name, &val->frdataset, DNS_R_NCACHENXRRSET))
+ {
+ result = markanswer(val, "validator_callback_ds",
+ "no DS and this is a delegation");
+ } else if ((val->attributes & VALATTR_INSECURITY) != 0) {
+ result = proveunsecure(val, have_dsset, true);
+ } else {
+ result = validate_dnskey(val);
+ }
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else {
+ if (eresult != DNS_R_BROKENCHAIN) {
+ expire_rdatasets(val);
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "validator_callback_ds: got %s",
+ isc_result_totext(eresult));
+ validator_done(val, DNS_R_BROKENCHAIN);
+ }
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+/*%
+ * Callback when the CNAME record has been validated.
+ *
+ * Resumes validation of the unsecure zone proof.
+ */
+static void
+validator_callback_cname(isc_task_t *task, isc_event_t *event) {
+ dns_validatorevent_t *devent;
+ dns_validator_t *val;
+ bool want_destroy;
+ isc_result_t result;
+ isc_result_t eresult;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);
+
+ devent = (dns_validatorevent_t *)event;
+ val = devent->ev_arg;
+ eresult = devent->result;
+
+ isc_event_free(&event);
+ dns_validator_destroy(&val->subvalidator);
+
+ INSIST(val->event != NULL);
+ INSIST((val->attributes & VALATTR_INSECURITY) != 0);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in validator_callback_cname");
+ LOCK(&val->lock);
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ } else if (eresult == ISC_R_SUCCESS) {
+ validator_log(val, ISC_LOG_DEBUG(3), "cname with trust %s",
+ dns_trust_totext(val->frdataset.trust));
+ result = proveunsecure(val, false, true);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ } else {
+ if (eresult != DNS_R_BROKENCHAIN) {
+ expire_rdatasets(val);
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "validator_callback_cname: got %s",
+ isc_result_totext(eresult));
+ validator_done(val, DNS_R_BROKENCHAIN);
+ }
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+/*%
+ * Callback for when NSEC records have been validated.
+ *
+ * Looks for NOQNAME, NODATA and OPTOUT proofs.
+ *
+ * Resumes the negative response validation by calling validate_nx().
+ */
+static void
+validator_callback_nsec(isc_task_t *task, isc_event_t *event) {
+ dns_validatorevent_t *devent;
+ dns_validator_t *val;
+ dns_rdataset_t *rdataset;
+ bool want_destroy;
+ isc_result_t result;
+ bool exists, data;
+
+ UNUSED(task);
+ INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);
+
+ devent = (dns_validatorevent_t *)event;
+ rdataset = devent->rdataset;
+ val = devent->ev_arg;
+ result = devent->result;
+ dns_validator_destroy(&val->subvalidator);
+
+ INSIST(val->event != NULL);
+
+ validator_log(val, ISC_LOG_DEBUG(3), "in validator_callback_nsec");
+ LOCK(&val->lock);
+ if (CANCELED(val)) {
+ validator_done(val, ISC_R_CANCELED);
+ } else if (result != ISC_R_SUCCESS) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "validator_callback_nsec: got %s",
+ isc_result_totext(result));
+ if (result == DNS_R_BROKENCHAIN) {
+ val->authfail++;
+ }
+ if (result == ISC_R_CANCELED) {
+ validator_done(val, result);
+ } else {
+ result = validate_nx(val, true);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ }
+ } else {
+ dns_name_t **proofs = val->event->proofs;
+ dns_name_t *wild = dns_fixedname_name(&val->wild);
+
+ if (rdataset->type == dns_rdatatype_nsec &&
+ rdataset->trust == dns_trust_secure &&
+ (NEEDNODATA(val) || NEEDNOQNAME(val)) &&
+ !FOUNDNODATA(val) && !FOUNDNOQNAME(val) &&
+ dns_nsec_noexistnodata(val->event->type, val->event->name,
+ devent->name, rdataset, &exists,
+ &data, wild, validator_log,
+ val) == ISC_R_SUCCESS)
+ {
+ if (exists && !data) {
+ val->attributes |= VALATTR_FOUNDNODATA;
+ if (NEEDNODATA(val)) {
+ proofs[DNS_VALIDATOR_NODATAPROOF] =
+ devent->name;
+ }
+ }
+ if (!exists) {
+ dns_name_t *closest;
+ unsigned int clabels;
+
+ val->attributes |= VALATTR_FOUNDNOQNAME;
+
+ closest = dns_fixedname_name(&val->closest);
+ clabels = dns_name_countlabels(closest);
+ /*
+ * If we are validating a wildcard response
+ * clabels will not be zero. We then need
+ * to check if the generated wildcard from
+ * dns_nsec_noexistnodata is consistent with
+ * the wildcard used to generate the response.
+ */
+ if (clabels == 0 ||
+ dns_name_countlabels(wild) == clabels + 1)
+ {
+ val->attributes |= VALATTR_FOUNDCLOSEST;
+ }
+ /*
+ * The NSEC noqname proof also contains
+ * the closest encloser.
+ */
+ if (NEEDNOQNAME(val)) {
+ proofs[DNS_VALIDATOR_NOQNAMEPROOF] =
+ devent->name;
+ }
+ }
+ }
+
+ result = validate_nx(val, true);
+ if (result != DNS_R_WAIT) {
+ validator_done(val, result);
+ }
+ }
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+
+ /*
+ * Free stuff from the event.
+ */
+ isc_event_free(&event);
+}
+
+/*%
+ * Looks for the requested name and type in the view (zones and cache).
+ *
+ * Returns:
+ * \li ISC_R_SUCCESS
+ * \li ISC_R_NOTFOUND
+ * \li DNS_R_NCACHENXDOMAIN
+ * \li DNS_R_NCACHENXRRSET
+ * \li DNS_R_NXRRSET
+ * \li DNS_R_NXDOMAIN
+ * \li DNS_R_BROKENCHAIN
+ */
+static isc_result_t
+view_find(dns_validator_t *val, dns_name_t *name, dns_rdatatype_t type) {
+ dns_fixedname_t fixedname;
+ dns_name_t *foundname;
+ isc_result_t result;
+ unsigned int options;
+ isc_time_t now;
+ char namebuf[DNS_NAME_FORMATSIZE];
+ char typebuf[DNS_RDATATYPE_FORMATSIZE];
+
+ disassociate_rdatasets(val);
+
+ if (isc_time_now(&now) == ISC_R_SUCCESS &&
+ dns_resolver_getbadcache(val->view->resolver, name, type, &now))
+ {
+ dns_name_format(name, namebuf, sizeof(namebuf));
+ dns_rdatatype_format(type, typebuf, sizeof(typebuf));
+ validator_log(val, ISC_LOG_INFO, "bad cache hit (%s/%s)",
+ namebuf, typebuf);
+ return (DNS_R_BROKENCHAIN);
+ }
+
+ options = DNS_DBFIND_PENDINGOK;
+ foundname = dns_fixedname_initname(&fixedname);
+ result = dns_view_find(val->view, name, type, 0, options, false, false,
+ NULL, NULL, foundname, &val->frdataset,
+ &val->fsigrdataset);
+
+ if (result == DNS_R_NXDOMAIN) {
+ goto notfound;
+ } else if (result != ISC_R_SUCCESS && result != DNS_R_NCACHENXDOMAIN &&
+ result != DNS_R_NCACHENXRRSET && result != DNS_R_EMPTYNAME &&
+ result != DNS_R_NXRRSET && result != ISC_R_NOTFOUND)
+ {
+ result = ISC_R_NOTFOUND;
+ goto notfound;
+ }
+
+ return (result);
+
+notfound:
+ disassociate_rdatasets(val);
+
+ return (result);
+}
+
+/*%
+ * Checks to make sure we are not going to loop. As we use a SHARED fetch
+ * the validation process will stall if looping was to occur.
+ */
+static bool
+check_deadlock(dns_validator_t *val, dns_name_t *name, dns_rdatatype_t type,
+ dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
+ dns_validator_t *parent;
+
+ for (parent = val; parent != NULL; parent = parent->parent) {
+ if (parent->event != NULL && parent->event->type == type &&
+ dns_name_equal(parent->event->name, name) &&
+ /*
+ * As NSEC3 records are meta data you sometimes
+ * need to prove a NSEC3 record which says that
+ * itself doesn't exist.
+ */
+ (parent->event->type != dns_rdatatype_nsec3 ||
+ rdataset == NULL || sigrdataset == NULL ||
+ parent->event->message == NULL ||
+ parent->event->rdataset != NULL ||
+ parent->event->sigrdataset != NULL))
+ {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "continuing validation would lead to "
+ "deadlock: aborting validation");
+ return (true);
+ }
+ }
+ return (false);
+}
+
+/*%
+ * Start a fetch for the requested name and type.
+ */
+static isc_result_t
+create_fetch(dns_validator_t *val, dns_name_t *name, dns_rdatatype_t type,
+ isc_taskaction_t callback, const char *caller) {
+ unsigned int fopts = 0;
+
+ disassociate_rdatasets(val);
+
+ if (check_deadlock(val, name, type, NULL, NULL)) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "deadlock found (create_fetch)");
+ return (DNS_R_NOVALIDSIG);
+ }
+
+ if ((val->options & DNS_VALIDATOR_NOCDFLAG) != 0) {
+ fopts |= DNS_FETCHOPT_NOCDFLAG;
+ }
+
+ if ((val->options & DNS_VALIDATOR_NONTA) != 0) {
+ fopts |= DNS_FETCHOPT_NONTA;
+ }
+
+ validator_logcreate(val, name, type, caller, "fetch");
+ return (dns_resolver_createfetch(
+ val->view->resolver, name, type, NULL, NULL, NULL, NULL, 0,
+ fopts, 0, NULL, val->event->ev_sender, callback, val,
+ &val->frdataset, &val->fsigrdataset, &val->fetch));
+}
+
+/*%
+ * Start a subvalidation process.
+ */
+static isc_result_t
+create_validator(dns_validator_t *val, dns_name_t *name, dns_rdatatype_t type,
+ dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
+ isc_taskaction_t action, const char *caller) {
+ isc_result_t result;
+ unsigned int vopts = 0;
+ dns_rdataset_t *sig = NULL;
+
+ if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset)) {
+ sig = sigrdataset;
+ }
+
+ if (check_deadlock(val, name, type, rdataset, sig)) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "deadlock found (create_validator)");
+ return (DNS_R_NOVALIDSIG);
+ }
+
+ /* OK to clear other options, but preserve NOCDFLAG and NONTA. */
+ vopts |= (val->options &
+ (DNS_VALIDATOR_NOCDFLAG | DNS_VALIDATOR_NONTA));
+
+ validator_logcreate(val, name, type, caller, "validator");
+ result = dns_validator_create(val->view, name, type, rdataset, sig,
+ NULL, vopts, val->task, action, val,
+ &val->subvalidator);
+ if (result == ISC_R_SUCCESS) {
+ val->subvalidator->parent = val;
+ val->subvalidator->depth = val->depth + 1;
+ }
+ return (result);
+}
+
+/*%
+ * Try to find a key that could have signed val->siginfo among those in
+ * 'rdataset'. If found, build a dst_key_t for it and point val->key at
+ * it.
+ *
+ * If val->key is already non-NULL, locate it in the rdataset and then
+ * search past it for the *next* key that could have signed 'siginfo', then
+ * set val->key to that.
+ *
+ * Returns ISC_R_SUCCESS if a possible matching key has been found,
+ * ISC_R_NOTFOUND if not. Any other value indicates error.
+ */
+static isc_result_t
+select_signing_key(dns_validator_t *val, dns_rdataset_t *rdataset) {
+ isc_result_t result;
+ dns_rdata_rrsig_t *siginfo = val->siginfo;
+ isc_buffer_t b;
+ dns_rdata_t rdata = DNS_RDATA_INIT;
+ dst_key_t *oldkey = val->key;
+ bool foundold;
+
+ if (oldkey == NULL) {
+ foundold = true;
+ } else {
+ foundold = false;
+ val->key = NULL;
+ }
+
+ result = dns_rdataset_first(rdataset);
+ if (result != ISC_R_SUCCESS) {
+ goto failure;
+ }
+ do {
+ dns_rdataset_current(rdataset, &rdata);
+
+ isc_buffer_init(&b, rdata.data, rdata.length);
+ isc_buffer_add(&b, rdata.length);
+ INSIST(val->key == NULL);
+ result = dst_key_fromdns(&siginfo->signer, rdata.rdclass, &b,
+ val->view->mctx, &val->key);
+ if (result == ISC_R_SUCCESS) {
+ if (siginfo->algorithm ==
+ (dns_secalg_t)dst_key_alg(val->key) &&
+ siginfo->keyid ==
+ (dns_keytag_t)dst_key_id(val->key) &&
+ dst_key_iszonekey(val->key))
+ {
+ if (foundold) {
+ /*
+ * This is the key we're looking for.
+ */
+ return (ISC_R_SUCCESS);
+ } else if (dst_key_compare(oldkey, val->key)) {
+ foundold = true;
+ dst_key_free(&oldkey);
+ }
+ }
+ dst_key_free(&val->key);
+ }
+ dns_rdata_reset(&rdata);
+ result = dns_rdataset_next(rdataset);
+ } while (result == ISC_R_SUCCESS);
+
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_NOTFOUND;
+ }
+
+failure:
+ if (oldkey != NULL) {
+ dst_key_free(&oldkey);
+ }
+
+ return (result);
+}
+
+/*%
+ * Get the key that generated the signature in val->siginfo.
+ */
+static isc_result_t
+seek_dnskey(dns_validator_t *val) {
+ isc_result_t result;
+ dns_rdata_rrsig_t *siginfo = val->siginfo;
+ unsigned int nlabels;
+ int order;
+ dns_namereln_t namereln;
+
+ /*
+ * Is the signer name appropriate for this signature?
+ *
+ * The signer name must be at the same level as the owner name
+ * or closer to the DNS root.
+ */
+ namereln = dns_name_fullcompare(val->event->name, &siginfo->signer,
+ &order, &nlabels);
+ if (namereln != dns_namereln_subdomain &&
+ namereln != dns_namereln_equal)
+ {
+ return (DNS_R_CONTINUE);
+ }
+
+ if (namereln == dns_namereln_equal) {
+ /*
+ * If this is a self-signed keyset, it must not be a zone key
+ * (since seek_dnskey is not called from validate_dnskey).
+ */
+ if (val->event->rdataset->type == dns_rdatatype_dnskey) {
+ return (DNS_R_CONTINUE);
+ }
+
+ /*
+ * Records appearing in the parent zone at delegation
+ * points cannot be self-signed.
+ */
+ if (dns_rdatatype_atparent(val->event->rdataset->type)) {
+ return (DNS_R_CONTINUE);
+ }
+ } else {
+ /*
+ * SOA and NS RRsets can only be signed by a key with
+ * the same name.
+ */
+ if (val->event->rdataset->type == dns_rdatatype_soa ||
+ val->event->rdataset->type == dns_rdatatype_ns)
+ {
+ const char *type;
+
+ if (val->event->rdataset->type == dns_rdatatype_soa) {
+ type = "SOA";
+ } else {
+ type = "NS";
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "%s signer mismatch", type);
+ return (DNS_R_CONTINUE);
+ }
+ }
+
+ /*
+ * Do we know about this key?
+ */
+ result = view_find(val, &siginfo->signer, dns_rdatatype_dnskey);
+ switch (result) {
+ case ISC_R_SUCCESS:
+ /*
+ * We have an rrset for the given keyname.
+ */
+ val->keyset = &val->frdataset;
+ if ((DNS_TRUST_PENDING(val->frdataset.trust) ||
+ DNS_TRUST_ANSWER(val->frdataset.trust)) &&
+ dns_rdataset_isassociated(&val->fsigrdataset))
+ {
+ /*
+ * We know the key but haven't validated it yet or
+ * we have a key of trust answer but a DS
+ * record for the zone may have been added.
+ */
+ result = create_validator(
+ val, &siginfo->signer, dns_rdatatype_dnskey,
+ &val->frdataset, &val->fsigrdataset,
+ validator_callback_dnskey, "seek_dnskey");
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ return (DNS_R_WAIT);
+ } else if (DNS_TRUST_PENDING(val->frdataset.trust)) {
+ /*
+ * Having a pending key with no signature means that
+ * something is broken.
+ */
+ result = DNS_R_CONTINUE;
+ } else if (val->frdataset.trust < dns_trust_secure) {
+ /*
+ * The key is legitimately insecure. There's no
+ * point in even attempting verification.
+ */
+ val->key = NULL;
+ result = ISC_R_SUCCESS;
+ } else {
+ /*
+ * See if we've got the key used in the signature.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "keyset with trust %s",
+ dns_trust_totext(val->frdataset.trust));
+ result = select_signing_key(val, val->keyset);
+ if (result != ISC_R_SUCCESS) {
+ /*
+ * Either the key we're looking for is not
+ * in the rrset, or something bad happened.
+ * Give up.
+ */
+ result = DNS_R_CONTINUE;
+ }
+ }
+ break;
+
+ case ISC_R_NOTFOUND:
+ /*
+ * We don't know anything about this key.
+ */
+ result = create_fetch(val, &siginfo->signer,
+ dns_rdatatype_dnskey,
+ fetch_callback_dnskey, "seek_dnskey");
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ return (DNS_R_WAIT);
+
+ case DNS_R_NCACHENXDOMAIN:
+ case DNS_R_NCACHENXRRSET:
+ case DNS_R_EMPTYNAME:
+ case DNS_R_NXDOMAIN:
+ case DNS_R_NXRRSET:
+ /*
+ * This key doesn't exist.
+ */
+ result = DNS_R_CONTINUE;
+ break;
+
+ case DNS_R_BROKENCHAIN:
+ return (result);
+
+ default:
+ break;
+ }
+
+ if (dns_rdataset_isassociated(&val->frdataset) &&
+ val->keyset != &val->frdataset)
+ {
+ dns_rdataset_disassociate(&val->frdataset);
+ }
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ dns_rdataset_disassociate(&val->fsigrdataset);
+ }
+
+ return (result);
+}
+
+/*
+ * Compute the tag for a key represented in a DNSKEY rdata.
+ */
+static dns_keytag_t
+compute_keytag(dns_rdata_t *rdata) {
+ isc_region_t r;
+
+ dns_rdata_toregion(rdata, &r);
+ return (dst_region_computeid(&r));
+}
+
+/*%
+ * Is the DNSKEY rrset in val->event->rdataset self-signed?
+ */
+static bool
+selfsigned_dnskey(dns_validator_t *val) {
+ dns_rdataset_t *rdataset = val->event->rdataset;
+ dns_rdataset_t *sigrdataset = val->event->sigrdataset;
+ dns_name_t *name = val->event->name;
+ isc_result_t result;
+ isc_mem_t *mctx = val->view->mctx;
+ bool answer = false;
+
+ if (rdataset->type != dns_rdatatype_dnskey) {
+ return (false);
+ }
+
+ for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(rdataset))
+ {
+ dns_rdata_t keyrdata = DNS_RDATA_INIT;
+ dns_rdata_t sigrdata = DNS_RDATA_INIT;
+ dns_rdata_dnskey_t key;
+ dns_rdata_rrsig_t sig;
+ dns_keytag_t keytag;
+
+ dns_rdata_reset(&keyrdata);
+ dns_rdataset_current(rdataset, &keyrdata);
+ result = dns_rdata_tostruct(&keyrdata, &key, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ keytag = compute_keytag(&keyrdata);
+
+ for (result = dns_rdataset_first(sigrdataset);
+ result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(sigrdataset))
+ {
+ dst_key_t *dstkey = NULL;
+
+ dns_rdata_reset(&sigrdata);
+ dns_rdataset_current(sigrdataset, &sigrdata);
+ result = dns_rdata_tostruct(&sigrdata, &sig, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+
+ if (sig.algorithm != key.algorithm ||
+ sig.keyid != keytag ||
+ !dns_name_equal(name, &sig.signer))
+ {
+ continue;
+ }
+
+ /*
+ * If the REVOKE bit is not set we have a
+ * theoretically self signed DNSKEY RRset.
+ * This will be verified later.
+ */
+ if ((key.flags & DNS_KEYFLAG_REVOKE) == 0) {
+ answer = true;
+ continue;
+ }
+
+ result = dns_dnssec_keyfromrdata(name, &keyrdata, mctx,
+ &dstkey);
+ if (result != ISC_R_SUCCESS) {
+ continue;
+ }
+
+ /*
+ * If this RRset is pending and it is trusted,
+ * see if it was self signed by this DNSKEY.
+ */
+ if (DNS_TRUST_PENDING(rdataset->trust) &&
+ dns_view_istrusted(val->view, name, &key))
+ {
+ result = dns_dnssec_verify(
+ name, rdataset, dstkey, true,
+ val->view->maxbits, mctx, &sigrdata,
+ NULL);
+ if (result == ISC_R_SUCCESS) {
+ /*
+ * The key with the REVOKE flag has
+ * self signed the RRset so it is no
+ * good.
+ */
+ dns_view_untrust(val->view, name, &key);
+ }
+ } else if (rdataset->trust >= dns_trust_secure) {
+ /*
+ * We trust this RRset so if the key is
+ * marked revoked remove it.
+ */
+ dns_view_untrust(val->view, name, &key);
+ }
+
+ dst_key_free(&dstkey);
+ }
+ }
+
+ return (answer);
+}
+
+/*%
+ * Attempt to verify the rdataset using the given key and rdata (RRSIG).
+ * The signature was good and from a wildcard record and the QNAME does
+ * not match the wildcard we need to look for a NOQNAME proof.
+ *
+ * Returns:
+ * \li ISC_R_SUCCESS if the verification succeeds.
+ * \li Others if the verification fails.
+ */
+static isc_result_t
+verify(dns_validator_t *val, dst_key_t *key, dns_rdata_t *rdata,
+ uint16_t keyid) {
+ isc_result_t result;
+ dns_fixedname_t fixed;
+ bool ignore = false;
+ dns_name_t *wild;
+
+ val->attributes |= VALATTR_TRIEDVERIFY;
+ wild = dns_fixedname_initname(&fixed);
+again:
+ result = dns_dnssec_verify(val->event->name, val->event->rdataset, key,
+ ignore, val->view->maxbits, val->view->mctx,
+ rdata, wild);
+ if ((result == DNS_R_SIGEXPIRED || result == DNS_R_SIGFUTURE) &&
+ val->view->acceptexpired)
+ {
+ ignore = true;
+ goto again;
+ }
+
+ if (ignore && (result == ISC_R_SUCCESS || result == DNS_R_FROMWILDCARD))
+ {
+ validator_log(val, ISC_LOG_INFO,
+ "accepted expired %sRRSIG (keyid=%u)",
+ (result == DNS_R_FROMWILDCARD) ? "wildcard " : "",
+ keyid);
+ } else if (result == DNS_R_SIGEXPIRED || result == DNS_R_SIGFUTURE) {
+ validator_log(val, ISC_LOG_INFO,
+ "verify failed due to bad signature (keyid=%u): "
+ "%s",
+ keyid, isc_result_totext(result));
+ } else {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "verify rdataset (keyid=%u): %s", keyid,
+ isc_result_totext(result));
+ }
+ if (result == DNS_R_FROMWILDCARD) {
+ if (!dns_name_equal(val->event->name, wild)) {
+ dns_name_t *closest;
+ unsigned int labels;
+
+ /*
+ * Compute the closest encloser in case we need it
+ * for the NSEC3 NOQNAME proof.
+ */
+ closest = dns_fixedname_name(&val->closest);
+ dns_name_copy(wild, closest);
+ labels = dns_name_countlabels(closest) - 1;
+ dns_name_getlabelsequence(closest, 1, labels, closest);
+ val->attributes |= VALATTR_NEEDNOQNAME;
+ }
+ result = ISC_R_SUCCESS;
+ }
+ return (result);
+}
+
+/*%
+ * Attempts positive response validation of a normal RRset.
+ *
+ * Returns:
+ * \li ISC_R_SUCCESS Validation completed successfully
+ * \li DNS_R_WAIT Validation has started but is waiting
+ * for an event.
+ * \li Other return codes are possible and all indicate failure.
+ */
+static isc_result_t
+validate_answer(dns_validator_t *val, bool resume) {
+ isc_result_t result, vresult = DNS_R_NOVALIDSIG;
+ dns_validatorevent_t *event;
+ dns_rdata_t rdata = DNS_RDATA_INIT;
+
+ /*
+ * Caller must be holding the validator lock.
+ */
+
+ event = val->event;
+
+ if (resume) {
+ /*
+ * We already have a sigrdataset.
+ */
+ result = ISC_R_SUCCESS;
+ validator_log(val, ISC_LOG_DEBUG(3), "resuming validate");
+ } else {
+ result = dns_rdataset_first(event->sigrdataset);
+ }
+
+ for (; result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(event->sigrdataset))
+ {
+ dns_rdata_reset(&rdata);
+ dns_rdataset_current(event->sigrdataset, &rdata);
+ if (val->siginfo == NULL) {
+ val->siginfo = isc_mem_get(val->view->mctx,
+ sizeof(*val->siginfo));
+ }
+ result = dns_rdata_tostruct(&rdata, val->siginfo, NULL);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+
+ /*
+ * At this point we could check that the signature algorithm
+ * was known and "sufficiently good".
+ */
+ if (!dns_resolver_algorithm_supported(val->view->resolver,
+ event->name,
+ val->siginfo->algorithm))
+ {
+ resume = false;
+ continue;
+ }
+
+ if (!resume) {
+ result = seek_dnskey(val);
+ if (result == DNS_R_CONTINUE) {
+ continue; /* Try the next SIG RR. */
+ }
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ }
+
+ /*
+ * There isn't a secure DNSKEY for this signature so move
+ * onto the next RRSIG.
+ */
+ if (val->key == NULL) {
+ resume = false;
+ continue;
+ }
+
+ do {
+ isc_result_t tresult;
+ vresult = verify(val, val->key, &rdata,
+ val->siginfo->keyid);
+ if (vresult == ISC_R_SUCCESS) {
+ break;
+ }
+
+ tresult = select_signing_key(val, val->keyset);
+ if (tresult != ISC_R_SUCCESS) {
+ break;
+ }
+ } while (1);
+ if (vresult != ISC_R_SUCCESS) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "failed to verify rdataset");
+ } else {
+ dns_rdataset_trimttl(event->rdataset,
+ event->sigrdataset, val->siginfo,
+ val->start,
+ val->view->acceptexpired);
+ }
+
+ if (val->key != NULL) {
+ dst_key_free(&val->key);
+ }
+ if (val->keyset != NULL) {
+ dns_rdataset_disassociate(val->keyset);
+ val->keyset = NULL;
+ }
+ val->key = NULL;
+ if (NEEDNOQNAME(val)) {
+ if (val->event->message == NULL) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no message available "
+ "for noqname proof");
+ return (DNS_R_NOVALIDSIG);
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "looking for noqname proof");
+ return (validate_nx(val, false));
+ } else if (vresult == ISC_R_SUCCESS) {
+ marksecure(event);
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "marking as secure, "
+ "noqname proof not needed");
+ return (ISC_R_SUCCESS);
+ } else {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "verify failure: %s",
+ isc_result_totext(result));
+ resume = false;
+ }
+ }
+ if (result != ISC_R_NOMORE) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "failed to iterate signatures: %s",
+ isc_result_totext(result));
+ return (result);
+ }
+
+ validator_log(val, ISC_LOG_INFO, "no valid signature found");
+ return (vresult);
+}
+
+/*%
+ * Check whether this DNSKEY (keyrdata) signed the DNSKEY RRset
+ * (val->event->rdataset).
+ */
+static isc_result_t
+check_signer(dns_validator_t *val, dns_rdata_t *keyrdata, uint16_t keyid,
+ dns_secalg_t algorithm) {
+ dns_rdata_rrsig_t sig;
+ dst_key_t *dstkey = NULL;
+ isc_result_t result;
+
+ for (result = dns_rdataset_first(val->event->sigrdataset);
+ result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(val->event->sigrdataset))
+ {
+ dns_rdata_t rdata = DNS_RDATA_INIT;
+
+ dns_rdataset_current(val->event->sigrdataset, &rdata);
+ result = dns_rdata_tostruct(&rdata, &sig, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ if (keyid != sig.keyid || algorithm != sig.algorithm) {
+ continue;
+ }
+ if (dstkey == NULL) {
+ result = dns_dnssec_keyfromrdata(
+ val->event->name, keyrdata, val->view->mctx,
+ &dstkey);
+ if (result != ISC_R_SUCCESS) {
+ /*
+ * This really shouldn't happen, but...
+ */
+ continue;
+ }
+ }
+ result = verify(val, dstkey, &rdata, sig.keyid);
+ if (result == ISC_R_SUCCESS) {
+ break;
+ }
+ }
+
+ if (dstkey != NULL) {
+ dst_key_free(&dstkey);
+ }
+
+ return (result);
+}
+
+/*
+ * get_dsset() is called to look up a DS RRset corresponding to the name
+ * of a DNSKEY record, either in the cache or, if necessary, by starting a
+ * fetch. This is done in the context of validating a zone key to build a
+ * trust chain.
+ *
+ * Returns:
+ * \li ISC_R_COMPLETE a DS has not been found; the caller should
+ * stop trying to validate the zone key and
+ * return the result code in '*resp'.
+ * \li DNS_R_CONTINUE a DS has been found and the caller may
+ * continue the zone key validation.
+ */
+static isc_result_t
+get_dsset(dns_validator_t *val, dns_name_t *tname, isc_result_t *resp) {
+ isc_result_t result;
+
+ result = view_find(val, tname, dns_rdatatype_ds);
+ switch (result) {
+ case ISC_R_SUCCESS:
+ /*
+ * We have a DS RRset.
+ */
+ val->dsset = &val->frdataset;
+ if ((DNS_TRUST_PENDING(val->frdataset.trust) ||
+ DNS_TRUST_ANSWER(val->frdataset.trust)) &&
+ dns_rdataset_isassociated(&val->fsigrdataset))
+ {
+ /*
+ * ... which is signed but not yet validated.
+ */
+ result = create_validator(
+ val, tname, dns_rdatatype_ds, &val->frdataset,
+ &val->fsigrdataset, validator_callback_ds,
+ "validate_dnskey");
+ *resp = DNS_R_WAIT;
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+ } else if (DNS_TRUST_PENDING(val->frdataset.trust)) {
+ /*
+ * There should never be an unsigned DS.
+ */
+ disassociate_rdatasets(val);
+ validator_log(val, ISC_LOG_DEBUG(2),
+ "unsigned DS record");
+ *resp = DNS_R_NOVALIDSIG;
+ return (ISC_R_COMPLETE);
+ }
+ break;
+
+ case ISC_R_NOTFOUND:
+ /*
+ * We don't have the DS. Find it.
+ */
+ result = create_fetch(val, tname, dns_rdatatype_ds,
+ fetch_callback_ds, "validate_dnskey");
+ *resp = DNS_R_WAIT;
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+
+ case DNS_R_NCACHENXDOMAIN:
+ case DNS_R_NCACHENXRRSET:
+ case DNS_R_EMPTYNAME:
+ case DNS_R_NXDOMAIN:
+ case DNS_R_NXRRSET:
+ case DNS_R_CNAME:
+ /*
+ * The DS does not exist.
+ */
+ disassociate_rdatasets(val);
+ validator_log(val, ISC_LOG_DEBUG(2), "no DS record");
+ *resp = DNS_R_NOVALIDSIG;
+ return (ISC_R_COMPLETE);
+
+ case DNS_R_BROKENCHAIN:
+ *resp = result;
+ return (ISC_R_COMPLETE);
+
+ default:
+ break;
+ }
+
+ return (DNS_R_CONTINUE);
+}
+
+/*%
+ * Attempts positive response validation of an RRset containing zone keys
+ * (i.e. a DNSKEY rrset).
+ *
+ * Caller must be holding the validator lock.
+ *
+ * Returns:
+ * \li ISC_R_SUCCESS Validation completed successfully
+ * \li DNS_R_WAIT Validation has started but is waiting
+ * for an event.
+ * \li Other return codes are possible and all indicate failure.
+ */
+static isc_result_t
+validate_dnskey(dns_validator_t *val) {
+ isc_result_t result;
+ dns_rdata_t dsrdata = DNS_RDATA_INIT;
+ dns_rdata_t keyrdata = DNS_RDATA_INIT;
+ dns_keynode_t *keynode = NULL;
+ dns_rdata_ds_t ds;
+ bool supported_algorithm;
+ char digest_types[256];
+
+ /*
+ * If we don't already have a DS RRset, check to see if there's
+ * a DS style trust anchor configured for this key.
+ */
+ if (val->dsset == NULL) {
+ result = dns_keytable_find(val->keytable, val->event->name,
+ &keynode);
+ if (result == ISC_R_SUCCESS) {
+ if (dns_keynode_dsset(keynode, &val->fdsset)) {
+ val->dsset = &val->fdsset;
+ }
+ dns_keytable_detachkeynode(val->keytable, &keynode);
+ }
+ }
+
+ /*
+ * No trust anchor for this name, so we look up the DS at the parent.
+ */
+ if (val->dsset == NULL) {
+ isc_result_t tresult = ISC_R_SUCCESS;
+
+ /*
+ * If this is the root name and there was no trust anchor,
+ * we can give up now, since there's no DS at the root.
+ */
+ if (dns_name_equal(val->event->name, dns_rootname)) {
+ if ((val->attributes & VALATTR_TRIEDVERIFY) != 0) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "root key failed to validate");
+ } else {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no trusted root key");
+ }
+ result = DNS_R_NOVALIDSIG;
+ goto cleanup;
+ }
+
+ /*
+ * Look up the DS RRset for this name.
+ */
+ result = get_dsset(val, val->event->name, &tresult);
+ if (result == ISC_R_COMPLETE) {
+ result = tresult;
+ goto cleanup;
+ }
+ }
+
+ /*
+ * We have a DS set.
+ */
+ INSIST(val->dsset != NULL);
+
+ if (val->dsset->trust < dns_trust_secure) {
+ result = markanswer(val, "validate_dnskey (2)", "insecure DS");
+ goto cleanup;
+ }
+
+ /*
+ * Look through the DS record and find the keys that can sign the
+ * key set and the matching signature. For each such key, attempt
+ * verification.
+ */
+
+ supported_algorithm = false;
+
+ /*
+ * If DNS_DSDIGEST_SHA256 or DNS_DSDIGEST_SHA384 is present we
+ * are required to prefer it over DNS_DSDIGEST_SHA1. This in
+ * practice means that we need to ignore DNS_DSDIGEST_SHA1 if a
+ * DNS_DSDIGEST_SHA256 or DNS_DSDIGEST_SHA384 is present.
+ */
+ memset(digest_types, 1, sizeof(digest_types));
+ for (result = dns_rdataset_first(val->dsset); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(val->dsset))
+ {
+ dns_rdata_reset(&dsrdata);
+ dns_rdataset_current(val->dsset, &dsrdata);
+ result = dns_rdata_tostruct(&dsrdata, &ds, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+
+ if (!dns_resolver_ds_digest_supported(val->view->resolver,
+ val->event->name,
+ ds.digest_type))
+ {
+ continue;
+ }
+
+ if (!dns_resolver_algorithm_supported(val->view->resolver,
+ val->event->name,
+ ds.algorithm))
+ {
+ continue;
+ }
+
+ if ((ds.digest_type == DNS_DSDIGEST_SHA256 &&
+ ds.length == ISC_SHA256_DIGESTLENGTH) ||
+ (ds.digest_type == DNS_DSDIGEST_SHA384 &&
+ ds.length == ISC_SHA384_DIGESTLENGTH))
+ {
+ digest_types[DNS_DSDIGEST_SHA1] = 0;
+ break;
+ }
+ }
+
+ for (result = dns_rdataset_first(val->dsset); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(val->dsset))
+ {
+ dns_rdata_reset(&dsrdata);
+ dns_rdataset_current(val->dsset, &dsrdata);
+ result = dns_rdata_tostruct(&dsrdata, &ds, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+
+ if (digest_types[ds.digest_type] == 0) {
+ continue;
+ }
+
+ if (!dns_resolver_ds_digest_supported(val->view->resolver,
+ val->event->name,
+ ds.digest_type))
+ {
+ continue;
+ }
+
+ if (!dns_resolver_algorithm_supported(val->view->resolver,
+ val->event->name,
+ ds.algorithm))
+ {
+ continue;
+ }
+
+ supported_algorithm = true;
+
+ /*
+ * Find the DNSKEY matching the DS...
+ */
+ result = dns_dnssec_matchdskey(val->event->name, &dsrdata,
+ val->event->rdataset, &keyrdata);
+ if (result != ISC_R_SUCCESS) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no DNSKEY matching DS");
+ continue;
+ }
+
+ /*
+ * ... and check that it signed the DNSKEY RRset.
+ */
+ result = check_signer(val, &keyrdata, ds.key_tag, ds.algorithm);
+ if (result == ISC_R_SUCCESS) {
+ break;
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no RRSIG matching DS key");
+ }
+
+ if (result == ISC_R_SUCCESS) {
+ marksecure(val->event);
+ validator_log(val, ISC_LOG_DEBUG(3), "marking as secure (DS)");
+ } else if (result == ISC_R_NOMORE && !supported_algorithm) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no supported algorithm/digest (DS)");
+ result = markanswer(val, "validate_dnskey (3)",
+ "no supported algorithm/digest (DS)");
+ } else {
+ validator_log(val, ISC_LOG_INFO,
+ "no valid signature found (DS)");
+ result = DNS_R_NOVALIDSIG;
+ }
+
+cleanup:
+ if (val->dsset == &val->fdsset) {
+ val->dsset = NULL;
+ dns_rdataset_disassociate(&val->fdsset);
+ }
+
+ return (result);
+}
+
+/*%
+ * val_rdataset_first and val_rdataset_next provide iteration methods
+ * that hide whether we are iterating across the AUTHORITY section of
+ * a message, or a negative cache rdataset.
+ */
+static isc_result_t
+val_rdataset_first(dns_validator_t *val, dns_name_t **namep,
+ dns_rdataset_t **rdatasetp) {
+ dns_message_t *message = val->event->message;
+ isc_result_t result;
+
+ REQUIRE(rdatasetp != NULL);
+ REQUIRE(namep != NULL);
+ if (message == NULL) {
+ REQUIRE(*rdatasetp != NULL);
+ REQUIRE(*namep != NULL);
+ } else {
+ REQUIRE(*rdatasetp == NULL);
+ REQUIRE(*namep == NULL);
+ }
+
+ if (message != NULL) {
+ result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ dns_message_currentname(message, DNS_SECTION_AUTHORITY, namep);
+ *rdatasetp = ISC_LIST_HEAD((*namep)->list);
+ INSIST(*rdatasetp != NULL);
+ } else {
+ result = dns_rdataset_first(val->event->rdataset);
+ if (result == ISC_R_SUCCESS) {
+ dns_ncache_current(val->event->rdataset, *namep,
+ *rdatasetp);
+ }
+ }
+ return (result);
+}
+
+static isc_result_t
+val_rdataset_next(dns_validator_t *val, dns_name_t **namep,
+ dns_rdataset_t **rdatasetp) {
+ dns_message_t *message = val->event->message;
+ isc_result_t result = ISC_R_SUCCESS;
+
+ REQUIRE(rdatasetp != NULL && *rdatasetp != NULL);
+ REQUIRE(namep != NULL && *namep != NULL);
+
+ if (message != NULL) {
+ dns_rdataset_t *rdataset = *rdatasetp;
+ rdataset = ISC_LIST_NEXT(rdataset, link);
+ if (rdataset == NULL) {
+ *namep = NULL;
+ result = dns_message_nextname(message,
+ DNS_SECTION_AUTHORITY);
+ if (result == ISC_R_SUCCESS) {
+ dns_message_currentname(
+ message, DNS_SECTION_AUTHORITY, namep);
+ rdataset = ISC_LIST_HEAD((*namep)->list);
+ INSIST(rdataset != NULL);
+ }
+ }
+ *rdatasetp = rdataset;
+ } else {
+ dns_rdataset_disassociate(*rdatasetp);
+ result = dns_rdataset_next(val->event->rdataset);
+ if (result == ISC_R_SUCCESS) {
+ dns_ncache_current(val->event->rdataset, *namep,
+ *rdatasetp);
+ }
+ }
+ return (result);
+}
+
+/*%
+ * Look for NODATA at the wildcard and NOWILDCARD proofs in the
+ * previously validated NSEC records. As these proofs are mutually
+ * exclusive we stop when one is found.
+ *
+ * Returns
+ * \li ISC_R_SUCCESS
+ */
+static isc_result_t
+checkwildcard(dns_validator_t *val, dns_rdatatype_t type,
+ dns_name_t *zonename) {
+ dns_name_t *name, *wild, tname;
+ isc_result_t result;
+ bool exists, data;
+ char namebuf[DNS_NAME_FORMATSIZE];
+ dns_rdataset_t *rdataset, trdataset;
+
+ dns_name_init(&tname, NULL);
+ dns_rdataset_init(&trdataset);
+ wild = dns_fixedname_name(&val->wild);
+
+ if (dns_name_countlabels(wild) == 0) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "in checkwildcard: no wildcard to check");
+ return (ISC_R_SUCCESS);
+ }
+
+ dns_name_format(wild, namebuf, sizeof(namebuf));
+ validator_log(val, ISC_LOG_DEBUG(3), "in checkwildcard: %s", namebuf);
+
+ if (val->event->message == NULL) {
+ name = &tname;
+ rdataset = &trdataset;
+ } else {
+ name = NULL;
+ rdataset = NULL;
+ }
+
+ for (result = val_rdataset_first(val, &name, &rdataset);
+ result == ISC_R_SUCCESS;
+ result = val_rdataset_next(val, &name, &rdataset))
+ {
+ if (rdataset->type != type ||
+ rdataset->trust != dns_trust_secure)
+ {
+ continue;
+ }
+
+ if (rdataset->type == dns_rdatatype_nsec &&
+ (NEEDNODATA(val) || NEEDNOWILDCARD(val)) &&
+ !FOUNDNODATA(val) && !FOUNDNOWILDCARD(val) &&
+ dns_nsec_noexistnodata(val->event->type, wild, name,
+ rdataset, &exists, &data, NULL,
+ validator_log, val) == ISC_R_SUCCESS)
+ {
+ dns_name_t **proofs = val->event->proofs;
+ if (exists && !data) {
+ val->attributes |= VALATTR_FOUNDNODATA;
+ }
+ if (exists && !data && NEEDNODATA(val)) {
+ proofs[DNS_VALIDATOR_NODATAPROOF] = name;
+ }
+ if (!exists) {
+ val->attributes |= VALATTR_FOUNDNOWILDCARD;
+ }
+ if (!exists && NEEDNOQNAME(val)) {
+ proofs[DNS_VALIDATOR_NOWILDCARDPROOF] = name;
+ }
+ if (dns_rdataset_isassociated(&trdataset)) {
+ dns_rdataset_disassociate(&trdataset);
+ }
+ return (ISC_R_SUCCESS);
+ }
+
+ if (rdataset->type == dns_rdatatype_nsec3 &&
+ (NEEDNODATA(val) || NEEDNOWILDCARD(val)) &&
+ !FOUNDNODATA(val) && !FOUNDNOWILDCARD(val) &&
+ dns_nsec3_noexistnodata(
+ val->event->type, wild, name, rdataset, zonename,
+ &exists, &data, NULL, NULL, NULL, NULL, NULL, NULL,
+ validator_log, val) == ISC_R_SUCCESS)
+ {
+ dns_name_t **proofs = val->event->proofs;
+ if (exists && !data) {
+ val->attributes |= VALATTR_FOUNDNODATA;
+ }
+ if (exists && !data && NEEDNODATA(val)) {
+ proofs[DNS_VALIDATOR_NODATAPROOF] = name;
+ }
+ if (!exists) {
+ val->attributes |= VALATTR_FOUNDNOWILDCARD;
+ }
+ if (!exists && NEEDNOQNAME(val)) {
+ proofs[DNS_VALIDATOR_NOWILDCARDPROOF] = name;
+ }
+ if (dns_rdataset_isassociated(&trdataset)) {
+ dns_rdataset_disassociate(&trdataset);
+ }
+ return (ISC_R_SUCCESS);
+ }
+ }
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+ if (dns_rdataset_isassociated(&trdataset)) {
+ dns_rdataset_disassociate(&trdataset);
+ }
+ return (result);
+}
+
+/*
+ * Look for the needed proofs for a negative or wildcard response
+ * from a zone using NSEC3, and set flags in the validator as they
+ * are found.
+ */
+static isc_result_t
+findnsec3proofs(dns_validator_t *val) {
+ dns_name_t *name, tname;
+ isc_result_t result;
+ bool exists, data, optout, unknown;
+ bool setclosest, setnearest, *setclosestp;
+ dns_fixedname_t fclosest, fnearest, fzonename;
+ dns_name_t *closest, *nearest, *zonename, *closestp;
+ dns_name_t **proofs = val->event->proofs;
+ dns_rdataset_t *rdataset, trdataset;
+
+ dns_name_init(&tname, NULL);
+ dns_rdataset_init(&trdataset);
+ closest = dns_fixedname_initname(&fclosest);
+ nearest = dns_fixedname_initname(&fnearest);
+ zonename = dns_fixedname_initname(&fzonename);
+
+ if (val->event->message == NULL) {
+ name = &tname;
+ rdataset = &trdataset;
+ } else {
+ name = NULL;
+ rdataset = NULL;
+ }
+
+ for (result = val_rdataset_first(val, &name, &rdataset);
+ result == ISC_R_SUCCESS;
+ result = val_rdataset_next(val, &name, &rdataset))
+ {
+ if (rdataset->type != dns_rdatatype_nsec3 ||
+ rdataset->trust != dns_trust_secure)
+ {
+ continue;
+ }
+
+ result = dns_nsec3_noexistnodata(
+ val->event->type, val->event->name, name, rdataset,
+ zonename, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL, validator_log, val);
+ if (result != ISC_R_IGNORE && result != ISC_R_SUCCESS) {
+ if (dns_rdataset_isassociated(&trdataset)) {
+ dns_rdataset_disassociate(&trdataset);
+ }
+ return (result);
+ }
+ }
+ if (result != ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+ POST(result);
+
+ if (dns_name_countlabels(zonename) == 0) {
+ return (ISC_R_SUCCESS);
+ }
+
+ /*
+ * If the val->closest is set then we want to use it otherwise
+ * we need to discover it.
+ */
+ if (dns_name_countlabels(dns_fixedname_name(&val->closest)) != 0) {
+ char namebuf[DNS_NAME_FORMATSIZE];
+
+ dns_name_format(dns_fixedname_name(&val->closest), namebuf,
+ sizeof(namebuf));
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "closest encloser from wildcard signature '%s'",
+ namebuf);
+ dns_name_copy(dns_fixedname_name(&val->closest), closest);
+ closestp = NULL;
+ setclosestp = NULL;
+ } else {
+ closestp = closest;
+ setclosestp = &setclosest;
+ }
+
+ for (result = val_rdataset_first(val, &name, &rdataset);
+ result == ISC_R_SUCCESS;
+ result = val_rdataset_next(val, &name, &rdataset))
+ {
+ if (rdataset->type != dns_rdatatype_nsec3 ||
+ rdataset->trust != dns_trust_secure)
+ {
+ continue;
+ }
+
+ /*
+ * We process all NSEC3 records to find the closest
+ * encloser and nearest name to the closest encloser.
+ */
+ setclosest = setnearest = false;
+ optout = false;
+ unknown = false;
+ result = dns_nsec3_noexistnodata(
+ val->event->type, val->event->name, name, rdataset,
+ zonename, &exists, &data, &optout, &unknown,
+ setclosestp, &setnearest, closestp, nearest,
+ validator_log, val);
+ if (unknown) {
+ val->attributes |= VALATTR_FOUNDUNKNOWN;
+ }
+ if (result == DNS_R_NSEC3ITERRANGE) {
+ /*
+ * We don't really know which NSEC3 record provides
+ * which proof. Just populate them.
+ */
+ if (NEEDNOQNAME(val) &&
+ proofs[DNS_VALIDATOR_NOQNAMEPROOF] == NULL)
+ {
+ proofs[DNS_VALIDATOR_NOQNAMEPROOF] = name;
+ } else if (setclosest) {
+ proofs[DNS_VALIDATOR_CLOSESTENCLOSER] = name;
+ } else if (NEEDNODATA(val) &&
+ proofs[DNS_VALIDATOR_NODATAPROOF] == NULL)
+ {
+ proofs[DNS_VALIDATOR_NODATAPROOF] = name;
+ } else if (NEEDNOWILDCARD(val) &&
+ proofs[DNS_VALIDATOR_NOWILDCARDPROOF] ==
+ NULL)
+ {
+ proofs[DNS_VALIDATOR_NOWILDCARDPROOF] = name;
+ }
+ return (result);
+ }
+ if (result != ISC_R_SUCCESS) {
+ continue;
+ }
+ if (setclosest) {
+ proofs[DNS_VALIDATOR_CLOSESTENCLOSER] = name;
+ }
+ if (exists && !data && NEEDNODATA(val)) {
+ val->attributes |= VALATTR_FOUNDNODATA;
+ proofs[DNS_VALIDATOR_NODATAPROOF] = name;
+ }
+ if (!exists && setnearest) {
+ val->attributes |= VALATTR_FOUNDNOQNAME;
+ proofs[DNS_VALIDATOR_NOQNAMEPROOF] = name;
+ if (optout) {
+ val->attributes |= VALATTR_FOUNDOPTOUT;
+ }
+ }
+ }
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+
+ /*
+ * To know we have a valid noqname and optout proofs we need to also
+ * have a valid closest encloser. Otherwise we could still be looking
+ * at proofs from the parent zone.
+ */
+ if (dns_name_countlabels(closest) > 0 &&
+ dns_name_countlabels(nearest) ==
+ dns_name_countlabels(closest) + 1 &&
+ dns_name_issubdomain(nearest, closest))
+ {
+ val->attributes |= VALATTR_FOUNDCLOSEST;
+ result = dns_name_concatenate(dns_wildcardname, closest,
+ dns_fixedname_name(&val->wild),
+ NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ } else {
+ val->attributes &= ~VALATTR_FOUNDNOQNAME;
+ val->attributes &= ~VALATTR_FOUNDOPTOUT;
+ proofs[DNS_VALIDATOR_NOQNAMEPROOF] = NULL;
+ }
+
+ /*
+ * Do we need to check for the wildcard?
+ */
+ if (FOUNDNOQNAME(val) && FOUNDCLOSEST(val) &&
+ ((NEEDNODATA(val) && !FOUNDNODATA(val)) || NEEDNOWILDCARD(val)))
+ {
+ result = checkwildcard(val, dns_rdatatype_nsec3, zonename);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ }
+ return (result);
+}
+
+/*
+ * Start a validator for negative response data.
+ *
+ * Returns:
+ * \li DNS_R_CONTINUE Validation skipped, continue
+ * \li DNS_R_WAIT Validation is in progress
+ *
+ * \li Other return codes indicate failure.
+ */
+static isc_result_t
+validate_neg_rrset(dns_validator_t *val, dns_name_t *name,
+ dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
+ isc_result_t result;
+
+ /*
+ * If a signed zone is missing the zone key, bad
+ * things could happen. A query for data in the zone
+ * would lead to a query for the zone key, which
+ * would return a negative answer, which would contain
+ * an SOA and an NSEC signed by the missing key, which
+ * would trigger another query for the DNSKEY (since
+ * the first one is still in progress), and go into an
+ * infinite loop. Avoid that.
+ */
+ if (val->event->type == dns_rdatatype_dnskey &&
+ rdataset->type == dns_rdatatype_nsec &&
+ dns_name_equal(name, val->event->name))
+ {
+ dns_rdata_t nsec = DNS_RDATA_INIT;
+
+ result = dns_rdataset_first(rdataset);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ dns_rdataset_current(rdataset, &nsec);
+ if (dns_nsec_typepresent(&nsec, dns_rdatatype_soa)) {
+ return (DNS_R_CONTINUE);
+ }
+ }
+
+ val->currentset = rdataset;
+ result = create_validator(val, name, rdataset->type, rdataset,
+ sigrdataset, validator_callback_nsec,
+ "validate_neg_rrset");
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+
+ val->authcount++;
+ return (DNS_R_WAIT);
+}
+
+/*%
+ * Validate the authority section records.
+ */
+static isc_result_t
+validate_authority(dns_validator_t *val, bool resume) {
+ dns_name_t *name;
+ dns_message_t *message = val->event->message;
+ isc_result_t result;
+
+ if (!resume) {
+ result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
+ } else {
+ result = ISC_R_SUCCESS;
+ }
+
+ for (; result == ISC_R_SUCCESS;
+ result = dns_message_nextname(message, DNS_SECTION_AUTHORITY))
+ {
+ dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL;
+
+ name = NULL;
+ dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
+ if (resume) {
+ rdataset = ISC_LIST_NEXT(val->currentset, link);
+ val->currentset = NULL;
+ resume = false;
+ } else {
+ rdataset = ISC_LIST_HEAD(name->list);
+ }
+
+ for (; rdataset != NULL;
+ rdataset = ISC_LIST_NEXT(rdataset, link))
+ {
+ if (rdataset->type == dns_rdatatype_rrsig) {
+ continue;
+ }
+
+ for (sigrdataset = ISC_LIST_HEAD(name->list);
+ sigrdataset != NULL;
+ sigrdataset = ISC_LIST_NEXT(sigrdataset, link))
+ {
+ if (sigrdataset->type == dns_rdatatype_rrsig &&
+ sigrdataset->covers == rdataset->type)
+ {
+ break;
+ }
+ }
+
+ result = validate_neg_rrset(val, name, rdataset,
+ sigrdataset);
+ if (result != DNS_R_CONTINUE) {
+ return (result);
+ }
+ }
+ }
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+ return (result);
+}
+
+/*%
+ * Validate negative cache elements.
+ */
+static isc_result_t
+validate_ncache(dns_validator_t *val, bool resume) {
+ dns_name_t *name;
+ isc_result_t result;
+
+ if (!resume) {
+ result = dns_rdataset_first(val->event->rdataset);
+ } else {
+ result = dns_rdataset_next(val->event->rdataset);
+ }
+
+ for (; result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(val->event->rdataset))
+ {
+ dns_rdataset_t *rdataset, *sigrdataset = NULL;
+
+ disassociate_rdatasets(val);
+
+ name = dns_fixedname_initname(&val->fname);
+ rdataset = &val->frdataset;
+ dns_ncache_current(val->event->rdataset, name, rdataset);
+
+ if (val->frdataset.type == dns_rdatatype_rrsig) {
+ continue;
+ }
+
+ result = dns_ncache_getsigrdataset(val->event->rdataset, name,
+ rdataset->type,
+ &val->fsigrdataset);
+ if (result == ISC_R_SUCCESS) {
+ sigrdataset = &val->fsigrdataset;
+ }
+
+ result = validate_neg_rrset(val, name, rdataset, sigrdataset);
+ if (result == DNS_R_CONTINUE) {
+ continue;
+ }
+
+ return (result);
+ }
+ if (result == ISC_R_NOMORE) {
+ result = ISC_R_SUCCESS;
+ }
+
+ return (result);
+}
+
+/*%
+ * Prove a negative answer is good or that there is a NOQNAME when the
+ * answer is from a wildcard.
+ *
+ * Loop through the authority section looking for NODATA, NOWILDCARD
+ * and NOQNAME proofs in the NSEC records by calling
+ * validator_callback_nsec().
+ *
+ * If the required proofs are found we are done.
+ *
+ * If the proofs are not found attempt to prove this is an unsecure
+ * response.
+ */
+static isc_result_t
+validate_nx(dns_validator_t *val, bool resume) {
+ isc_result_t result;
+
+ if (resume) {
+ validator_log(val, ISC_LOG_DEBUG(3), "resuming validate_nx");
+ }
+
+ if (val->event->message == NULL) {
+ result = validate_ncache(val, resume);
+ } else {
+ result = validate_authority(val, resume);
+ }
+
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+
+ /*
+ * Do we only need to check for NOQNAME? To get here we must have
+ * had a secure wildcard answer.
+ */
+ if (!NEEDNODATA(val) && !NEEDNOWILDCARD(val) && NEEDNOQNAME(val)) {
+ if (!FOUNDNOQNAME(val)) {
+ result = findnsec3proofs(val);
+ if (result == DNS_R_NSEC3ITERRANGE) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "too many iterations");
+ markanswer(val, "validate_nx (3)", NULL);
+ return (ISC_R_SUCCESS);
+ }
+ }
+
+ if (FOUNDNOQNAME(val) && FOUNDCLOSEST(val) && !FOUNDOPTOUT(val))
+ {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "marking as secure, noqname proof found");
+ marksecure(val->event);
+ return (ISC_R_SUCCESS);
+ } else if (FOUNDOPTOUT(val) &&
+ dns_name_countlabels(
+ dns_fixedname_name(&val->wild)) != 0)
+ {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "optout proof found");
+ val->event->optout = true;
+ markanswer(val, "validate_nx (1)", NULL);
+ return (ISC_R_SUCCESS);
+ } else if ((val->attributes & VALATTR_FOUNDUNKNOWN) != 0) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "unknown NSEC3 hash algorithm found");
+ markanswer(val, "validate_nx (2)", NULL);
+ return (ISC_R_SUCCESS);
+ }
+
+ validator_log(val, ISC_LOG_DEBUG(3), "noqname proof not found");
+ return (DNS_R_NOVALIDNSEC);
+ }
+
+ if (!FOUNDNOQNAME(val) && !FOUNDNODATA(val)) {
+ result = findnsec3proofs(val);
+ if (result == DNS_R_NSEC3ITERRANGE) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "too many iterations");
+ markanswer(val, "validate_nx (4)", NULL);
+ return (ISC_R_SUCCESS);
+ }
+ }
+
+ /*
+ * Do we need to check for the wildcard?
+ */
+ if (FOUNDNOQNAME(val) && FOUNDCLOSEST(val) &&
+ ((NEEDNODATA(val) && !FOUNDNODATA(val)) || NEEDNOWILDCARD(val)))
+ {
+ result = checkwildcard(val, dns_rdatatype_nsec, NULL);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ }
+
+ if ((NEEDNODATA(val) && (FOUNDNODATA(val) || FOUNDOPTOUT(val))) ||
+ (NEEDNOQNAME(val) && FOUNDNOQNAME(val) && NEEDNOWILDCARD(val) &&
+ FOUNDNOWILDCARD(val) && FOUNDCLOSEST(val)))
+ {
+ if ((val->attributes & VALATTR_FOUNDOPTOUT) != 0) {
+ val->event->optout = true;
+ }
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "nonexistence proof(s) found");
+ if (val->event->message == NULL) {
+ marksecure(val->event);
+ } else {
+ val->event->secure = true;
+ }
+ return (ISC_R_SUCCESS);
+ }
+
+ if (val->authfail != 0 && val->authcount == val->authfail) {
+ return (DNS_R_BROKENCHAIN);
+ }
+
+ validator_log(val, ISC_LOG_DEBUG(3), "nonexistence proof(s) not found");
+ return (proveunsecure(val, false, false));
+}
+
+/*%
+ * Check that DS rdataset has at least one record with
+ * a supported algorithm and digest.
+ */
+static bool
+check_ds_algs(dns_validator_t *val, dns_name_t *name,
+ dns_rdataset_t *rdataset) {
+ dns_rdata_t dsrdata = DNS_RDATA_INIT;
+ dns_rdata_ds_t ds;
+ isc_result_t result;
+
+ for (result = dns_rdataset_first(rdataset); result == ISC_R_SUCCESS;
+ result = dns_rdataset_next(rdataset))
+ {
+ dns_rdataset_current(rdataset, &dsrdata);
+ result = dns_rdata_tostruct(&dsrdata, &ds, NULL);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+
+ if (dns_resolver_ds_digest_supported(val->view->resolver, name,
+ ds.digest_type) &&
+ dns_resolver_algorithm_supported(val->view->resolver, name,
+ ds.algorithm))
+ {
+ dns_rdata_reset(&dsrdata);
+ return (true);
+ }
+ dns_rdata_reset(&dsrdata);
+ }
+ return (false);
+}
+
+/*%
+ * seek_ds is called to look up DS rrsets at the label of val->event->name
+ * indicated by val->labels. This is done while building an insecurity
+ * proof, and so it will attempt validation of NXDOMAIN, NXRRSET or CNAME
+ * responses.
+ *
+ * Returns:
+ * \li ISC_R_COMPLETE a result has been determined and copied
+ * into `*resp`; ISC_R_SUCCESS indicates that
+ * the name has been proven insecure and any
+ * other result indicates failure.
+ * \li DNS_R_CONTINUE result is indeterminate; caller should
+ * continue walking down labels.
+ */
+static isc_result_t
+seek_ds(dns_validator_t *val, isc_result_t *resp) {
+ isc_result_t result;
+ char namebuf[DNS_NAME_FORMATSIZE];
+ dns_fixedname_t fixedfound;
+ dns_name_t *found = dns_fixedname_initname(&fixedfound);
+ dns_name_t *tname = dns_fixedname_initname(&val->fname);
+
+ if (val->labels == dns_name_countlabels(val->event->name)) {
+ dns_name_copy(val->event->name, tname);
+ } else {
+ dns_name_split(val->event->name, val->labels, NULL, tname);
+ }
+
+ dns_name_format(tname, namebuf, sizeof(namebuf));
+ validator_log(val, ISC_LOG_DEBUG(3), "checking existence of DS at '%s'",
+ namebuf);
+
+ result = view_find(val, tname, dns_rdatatype_ds);
+ switch (result) {
+ case ISC_R_SUCCESS:
+ /*
+ * There is a DS here. If it's already been
+ * validated, continue walking down labels.
+ */
+ if (val->frdataset.trust >= dns_trust_secure) {
+ if (!check_ds_algs(val, tname, &val->frdataset)) {
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no supported algorithm/"
+ "digest (%s/DS)",
+ namebuf);
+ *resp = markanswer(val, "proveunsecure (5)",
+ "no supported "
+ "algorithm/digest (DS)");
+ return (ISC_R_COMPLETE);
+ }
+
+ break;
+ }
+
+ /*
+ * Otherwise, try to validate it now.
+ */
+ if (dns_rdataset_isassociated(&val->fsigrdataset)) {
+ result = create_validator(
+ val, tname, dns_rdatatype_ds, &val->frdataset,
+ &val->fsigrdataset, validator_callback_ds,
+ "proveunsecure");
+ *resp = DNS_R_WAIT;
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ } else {
+ /*
+ * There should never be an unsigned DS.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "unsigned DS record");
+ *resp = DNS_R_NOVALIDSIG;
+ }
+
+ return (ISC_R_COMPLETE);
+
+ case ISC_R_NOTFOUND:
+ /*
+ * We don't know anything about the DS. Find it.
+ */
+ *resp = DNS_R_WAIT;
+ result = create_fetch(val, tname, dns_rdatatype_ds,
+ fetch_callback_ds, "proveunsecure");
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+
+ case DNS_R_NXRRSET:
+ case DNS_R_NCACHENXRRSET:
+ /*
+ * There is no DS. If this is a delegation,
+ * we may be done.
+ *
+ * If we have "trust == answer" then this namespace
+ * has switched from insecure to should be secure.
+ */
+ if (DNS_TRUST_PENDING(val->frdataset.trust) ||
+ DNS_TRUST_ANSWER(val->frdataset.trust))
+ {
+ result = create_validator(
+ val, tname, dns_rdatatype_ds, &val->frdataset,
+ &val->fsigrdataset, validator_callback_ds,
+ "proveunsecure");
+ *resp = DNS_R_WAIT;
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+ }
+
+ /*
+ * Zones using NSEC3 don't return a NSEC RRset so
+ * we need to use dns_view_findzonecut2 to find
+ * the zone cut.
+ */
+ if (result == DNS_R_NXRRSET &&
+ !dns_rdataset_isassociated(&val->frdataset) &&
+ dns_view_findzonecut(val->view, tname, found, NULL, 0, 0,
+ false, false, NULL,
+ NULL) == ISC_R_SUCCESS &&
+ dns_name_equal(tname, found))
+ {
+ *resp = markanswer(val, "proveunsecure (3)",
+ "no DS at zone cut");
+ return (ISC_R_COMPLETE);
+ }
+
+ if (val->frdataset.trust < dns_trust_secure) {
+ /*
+ * This shouldn't happen, since the negative
+ * response should have been validated. Since
+ * there's no way of validating existing
+ * negative response blobs, give up.
+ */
+ validator_log(val, ISC_LOG_WARNING,
+ "can't validate existing "
+ "negative responses (no DS)");
+ *resp = DNS_R_MUSTBESECURE;
+ return (ISC_R_COMPLETE);
+ }
+
+ if (isdelegation(tname, &val->frdataset, result)) {
+ *resp = markanswer(val, "proveunsecure (4)",
+ "this is a delegation");
+ return (ISC_R_COMPLETE);
+ }
+
+ break;
+
+ case DNS_R_NXDOMAIN:
+ case DNS_R_NCACHENXDOMAIN:
+ /*
+ * This is not a zone cut. Assuming things are
+ * as expected, continue.
+ */
+ if (!dns_rdataset_isassociated(&val->frdataset)) {
+ /*
+ * There should be an NSEC here, since we
+ * are still in a secure zone.
+ */
+ *resp = DNS_R_NOVALIDNSEC;
+ return (ISC_R_COMPLETE);
+ } else if (DNS_TRUST_PENDING(val->frdataset.trust) ||
+ DNS_TRUST_ANSWER(val->frdataset.trust))
+ {
+ /*
+ * If we have "trust == answer" then this
+ * namespace has switched from insecure to
+ * should be secure.
+ */
+ *resp = DNS_R_WAIT;
+ result = create_validator(
+ val, tname, dns_rdatatype_ds, &val->frdataset,
+ &val->fsigrdataset, validator_callback_ds,
+ "proveunsecure");
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+ } else if (val->frdataset.trust < dns_trust_secure) {
+ /*
+ * This shouldn't happen, since the negative
+ * response should have been validated. Since
+ * there's no way of validating existing
+ * negative response blobs, give up.
+ */
+ validator_log(val, ISC_LOG_WARNING,
+ "can't validate existing "
+ "negative responses "
+ "(not a zone cut)");
+ *resp = DNS_R_NOVALIDSIG;
+ return (ISC_R_COMPLETE);
+ }
+
+ break;
+
+ case DNS_R_CNAME:
+ if (DNS_TRUST_PENDING(val->frdataset.trust) ||
+ DNS_TRUST_ANSWER(val->frdataset.trust))
+ {
+ result = create_validator(
+ val, tname, dns_rdatatype_cname,
+ &val->frdataset, &val->fsigrdataset,
+ validator_callback_cname,
+ "proveunsecure "
+ "(cname)");
+ *resp = DNS_R_WAIT;
+ if (result != ISC_R_SUCCESS) {
+ *resp = result;
+ }
+ return (ISC_R_COMPLETE);
+ }
+
+ break;
+
+ default:
+ *resp = result;
+ return (ISC_R_COMPLETE);
+ }
+
+ /*
+ * No definite answer yet; continue walking down labels.
+ */
+ return (DNS_R_CONTINUE);
+}
+
+/*%
+ * proveunsecure walks down, label by label, from the closest enclosing
+ * trust anchor to the name that is being validated, looking for an
+ * endpoint in the chain of trust. That occurs when we can prove that
+ * a DS record does not exist at a delegation point, or that a DS exists
+ * at a delegation point but we don't support its algorithm/digest. If
+ * no such endpoint is found, then the response should have been secure.
+ *
+ * Returns:
+ * \li ISC_R_SUCCESS val->event->name is in an unsecure zone
+ * \li DNS_R_WAIT validation is in progress.
+ * \li DNS_R_MUSTBESECURE val->event->name is supposed to be secure
+ * (policy) but we proved that it is unsecure.
+ * \li DNS_R_NOVALIDSIG
+ * \li DNS_R_NOVALIDNSEC
+ * \li DNS_R_NOTINSECURE
+ * \li DNS_R_BROKENCHAIN
+ */
+static isc_result_t
+proveunsecure(dns_validator_t *val, bool have_ds, bool resume) {
+ isc_result_t result;
+ char namebuf[DNS_NAME_FORMATSIZE];
+ dns_fixedname_t fixedsecroot;
+ dns_name_t *secroot = dns_fixedname_initname(&fixedsecroot);
+ unsigned int labels;
+
+ /*
+ * We're attempting to prove insecurity.
+ */
+ val->attributes |= VALATTR_INSECURITY;
+
+ dns_name_copy(val->event->name, secroot);
+
+ /*
+ * If this is a response to a DS query, we need to look in
+ * the parent zone for the trust anchor.
+ */
+ labels = dns_name_countlabels(secroot);
+ if (val->event->type == dns_rdatatype_ds && labels > 1U) {
+ dns_name_getlabelsequence(secroot, 1, labels - 1, secroot);
+ }
+
+ result = dns_keytable_finddeepestmatch(val->keytable, secroot, secroot);
+ if (result == ISC_R_NOTFOUND) {
+ validator_log(val, ISC_LOG_DEBUG(3), "not beneath secure root");
+ return (markanswer(val, "proveunsecure (1)",
+ "not beneath secure root"));
+ } else if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+
+ if (!resume) {
+ /*
+ * We are looking for interruptions in the chain of trust.
+ * That can only happen *below* the trust anchor, so we
+ * start looking at the next label down.
+ */
+ val->labels = dns_name_countlabels(secroot) + 1;
+ } else {
+ validator_log(val, ISC_LOG_DEBUG(3), "resuming proveunsecure");
+
+ /*
+ * If we have a DS rdataset and it is secure, check whether
+ * it has a supported algorithm combination. If not, this is
+ * an insecure delegation as far as this resolver is concerned.
+ */
+ if (have_ds && val->frdataset.trust >= dns_trust_secure &&
+ !check_ds_algs(val, dns_fixedname_name(&val->fname),
+ &val->frdataset))
+ {
+ dns_name_format(dns_fixedname_name(&val->fname),
+ namebuf, sizeof(namebuf));
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "no supported algorithm/digest (%s/DS)",
+ namebuf);
+ result = markanswer(val, "proveunsecure (2)", namebuf);
+ goto out;
+ }
+ val->labels++;
+ }
+
+ /*
+ * Walk down through each of the remaining labels in the name,
+ * looking for DS records.
+ */
+ while (val->labels <= dns_name_countlabels(val->event->name)) {
+ isc_result_t tresult;
+
+ result = seek_ds(val, &tresult);
+ if (result == ISC_R_COMPLETE) {
+ result = tresult;
+ goto out;
+ }
+
+ INSIST(result == DNS_R_CONTINUE);
+ val->labels++;
+ }
+
+ /* Couldn't complete insecurity proof. */
+ validator_log(val, ISC_LOG_DEBUG(3), "insecurity proof failed: %s",
+ isc_result_totext(result));
+ return (DNS_R_NOTINSECURE);
+
+out:
+ if (result != DNS_R_WAIT) {
+ disassociate_rdatasets(val);
+ }
+ return (result);
+}
+
+/*%
+ * Start the validation process.
+ *
+ * Attempt to validate the answer based on the category it appears to
+ * fall in.
+ * \li 1. secure positive answer.
+ * \li 2. unsecure positive answer.
+ * \li 3. a negative answer (secure or unsecure).
+ *
+ * Note an answer that appears to be a secure positive answer may actually
+ * be an unsecure positive answer.
+ */
+static void
+validator_start(isc_task_t *task, isc_event_t *event) {
+ dns_validator_t *val;
+ dns_validatorevent_t *vevent;
+ bool want_destroy = false;
+ isc_result_t result = ISC_R_FAILURE;
+
+ UNUSED(task);
+ REQUIRE(event->ev_type == DNS_EVENT_VALIDATORSTART);
+ vevent = (dns_validatorevent_t *)event;
+ val = vevent->validator;
+
+ /* If the validator has been canceled, val->event == NULL */
+ if (val->event == NULL) {
+ return;
+ }
+
+ validator_log(val, ISC_LOG_DEBUG(3), "starting");
+
+ LOCK(&val->lock);
+
+ if (val->event->rdataset != NULL && val->event->sigrdataset != NULL) {
+ isc_result_t saved_result;
+
+ /*
+ * This looks like a simple validation. We say "looks like"
+ * because it might end up requiring an insecurity proof.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "attempting positive response validation");
+
+ INSIST(dns_rdataset_isassociated(val->event->rdataset));
+ INSIST(dns_rdataset_isassociated(val->event->sigrdataset));
+ if (selfsigned_dnskey(val)) {
+ result = validate_dnskey(val);
+ } else {
+ result = validate_answer(val, false);
+ }
+ if (result == DNS_R_NOVALIDSIG &&
+ (val->attributes & VALATTR_TRIEDVERIFY) == 0)
+ {
+ saved_result = result;
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "falling back to insecurity proof");
+ result = proveunsecure(val, false, false);
+ if (result == DNS_R_NOTINSECURE) {
+ result = saved_result;
+ }
+ }
+ } else if (val->event->rdataset != NULL &&
+ val->event->rdataset->type != 0)
+ {
+ /*
+ * This is either an unsecure subdomain or a response
+ * from a broken server.
+ */
+ INSIST(dns_rdataset_isassociated(val->event->rdataset));
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "attempting insecurity proof");
+
+ result = proveunsecure(val, false, false);
+ if (result == DNS_R_NOTINSECURE) {
+ validator_log(val, ISC_LOG_INFO,
+ "got insecure response; "
+ "parent indicates it should be secure");
+ }
+ } else if ((val->event->rdataset == NULL &&
+ val->event->sigrdataset == NULL))
+ {
+ /*
+ * This is a validation of a negative response.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "attempting negative response validation "
+ "from message");
+
+ if (val->event->message->rcode == dns_rcode_nxdomain) {
+ val->attributes |= VALATTR_NEEDNOQNAME;
+ val->attributes |= VALATTR_NEEDNOWILDCARD;
+ } else {
+ val->attributes |= VALATTR_NEEDNODATA;
+ }
+
+ result = validate_nx(val, false);
+ } else if ((val->event->rdataset != NULL &&
+ NEGATIVE(val->event->rdataset)))
+ {
+ /*
+ * This is a delayed validation of a negative cache entry.
+ */
+ validator_log(val, ISC_LOG_DEBUG(3),
+ "attempting negative response validation "
+ "from cache");
+
+ if (NXDOMAIN(val->event->rdataset)) {
+ val->attributes |= VALATTR_NEEDNOQNAME;
+ val->attributes |= VALATTR_NEEDNOWILDCARD;
+ } else {
+ val->attributes |= VALATTR_NEEDNODATA;
+ }
+
+ result = validate_nx(val, false);
+ } else {
+ UNREACHABLE();
+ }
+
+ if (result != DNS_R_WAIT) {
+ want_destroy = exit_check(val);
+ validator_done(val, result);
+ }
+
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+isc_result_t
+dns_validator_create(dns_view_t *view, dns_name_t *name, dns_rdatatype_t type,
+ dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
+ dns_message_t *message, unsigned int options,
+ isc_task_t *task, isc_taskaction_t action, void *arg,
+ dns_validator_t **validatorp) {
+ isc_result_t result = ISC_R_FAILURE;
+ dns_validator_t *val;
+ isc_task_t *tclone = NULL;
+ dns_validatorevent_t *event;
+
+ REQUIRE(name != NULL);
+ REQUIRE(rdataset != NULL ||
+ (rdataset == NULL && sigrdataset == NULL && message != NULL));
+ REQUIRE(validatorp != NULL && *validatorp == NULL);
+
+ event = (dns_validatorevent_t *)isc_event_allocate(
+ view->mctx, task, DNS_EVENT_VALIDATORSTART, validator_start,
+ NULL, sizeof(dns_validatorevent_t));
+
+ isc_task_attach(task, &tclone);
+ event->result = ISC_R_FAILURE;
+ event->name = name;
+ event->type = type;
+ event->rdataset = rdataset;
+ event->sigrdataset = sigrdataset;
+ event->message = message;
+ memset(event->proofs, 0, sizeof(event->proofs));
+ event->optout = false;
+ event->secure = false;
+
+ val = isc_mem_get(view->mctx, sizeof(*val));
+ *val = (dns_validator_t){ .event = event,
+ .options = options,
+ .task = task,
+ .action = action,
+ .arg = arg };
+
+ dns_view_weakattach(view, &val->view);
+ isc_mutex_init(&val->lock);
+
+ result = dns_view_getsecroots(val->view, &val->keytable);
+ if (result != ISC_R_SUCCESS) {
+ goto cleanup;
+ }
+
+ val->mustbesecure = dns_resolver_getmustbesecure(view->resolver, name);
+ dns_rdataset_init(&val->fdsset);
+ dns_rdataset_init(&val->frdataset);
+ dns_rdataset_init(&val->fsigrdataset);
+ dns_fixedname_init(&val->wild);
+ dns_fixedname_init(&val->closest);
+ isc_stdtime_get(&val->start);
+ ISC_LINK_INIT(val, link);
+ val->magic = VALIDATOR_MAGIC;
+
+ event->validator = val;
+
+ if ((options & DNS_VALIDATOR_DEFER) == 0) {
+ isc_task_send(task, ISC_EVENT_PTR(&event));
+ }
+
+ *validatorp = val;
+
+ return (ISC_R_SUCCESS);
+
+cleanup:
+ isc_mutex_destroy(&val->lock);
+
+ isc_task_detach(&tclone);
+ isc_event_free(ISC_EVENT_PTR(&event));
+
+ dns_view_weakdetach(&val->view);
+ isc_mem_put(view->mctx, val, sizeof(*val));
+
+ return (result);
+}
+
+void
+dns_validator_send(dns_validator_t *validator) {
+ isc_event_t *event;
+ REQUIRE(VALID_VALIDATOR(validator));
+
+ LOCK(&validator->lock);
+
+ INSIST((validator->options & DNS_VALIDATOR_DEFER) != 0);
+ event = (isc_event_t *)validator->event;
+ validator->options &= ~DNS_VALIDATOR_DEFER;
+ UNLOCK(&validator->lock);
+
+ isc_task_send(validator->task, ISC_EVENT_PTR(&event));
+}
+
+void
+dns_validator_cancel(dns_validator_t *validator) {
+ dns_fetch_t *fetch = NULL;
+
+ REQUIRE(VALID_VALIDATOR(validator));
+
+ LOCK(&validator->lock);
+
+ validator_log(validator, ISC_LOG_DEBUG(3), "dns_validator_cancel");
+
+ if ((validator->attributes & VALATTR_CANCELED) == 0) {
+ validator->attributes |= VALATTR_CANCELED;
+ if (validator->event != NULL) {
+ fetch = validator->fetch;
+ validator->fetch = NULL;
+
+ if (validator->subvalidator != NULL) {
+ dns_validator_cancel(validator->subvalidator);
+ }
+ if ((validator->options & DNS_VALIDATOR_DEFER) != 0) {
+ validator->options &= ~DNS_VALIDATOR_DEFER;
+ validator_done(validator, ISC_R_CANCELED);
+ }
+ }
+ }
+ UNLOCK(&validator->lock);
+
+ /* Need to cancel and destroy the fetch outside validator lock */
+ if (fetch != NULL) {
+ dns_resolver_cancelfetch(fetch);
+ dns_resolver_destroyfetch(&fetch);
+ }
+}
+
+static void
+destroy(dns_validator_t *val) {
+ isc_mem_t *mctx;
+
+ REQUIRE(SHUTDOWN(val));
+ REQUIRE(val->event == NULL);
+ REQUIRE(val->fetch == NULL);
+
+ val->magic = 0;
+ if (val->key != NULL) {
+ dst_key_free(&val->key);
+ }
+ if (val->keytable != NULL) {
+ dns_keytable_detach(&val->keytable);
+ }
+ if (val->subvalidator != NULL) {
+ dns_validator_destroy(&val->subvalidator);
+ }
+ disassociate_rdatasets(val);
+ mctx = val->view->mctx;
+ if (val->siginfo != NULL) {
+ isc_mem_put(mctx, val->siginfo, sizeof(*val->siginfo));
+ }
+ isc_mutex_destroy(&val->lock);
+ dns_view_weakdetach(&val->view);
+ isc_mem_put(mctx, val, sizeof(*val));
+}
+
+void
+dns_validator_destroy(dns_validator_t **validatorp) {
+ dns_validator_t *val;
+ bool want_destroy = false;
+
+ REQUIRE(validatorp != NULL);
+ val = *validatorp;
+ *validatorp = NULL;
+ REQUIRE(VALID_VALIDATOR(val));
+
+ LOCK(&val->lock);
+
+ val->attributes |= VALATTR_SHUTDOWN;
+ validator_log(val, ISC_LOG_DEBUG(4), "dns_validator_destroy");
+
+ want_destroy = exit_check(val);
+ UNLOCK(&val->lock);
+ if (want_destroy) {
+ destroy(val);
+ }
+}
+
+static void
+validator_logv(dns_validator_t *val, isc_logcategory_t *category,
+ isc_logmodule_t *module, int level, const char *fmt,
+ va_list ap) {
+ char msgbuf[2048];
+ static const char spaces[] = " *";
+ int depth = val->depth * 2;
+ const char *viewname, *sep1, *sep2;
+
+ vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
+
+ if ((unsigned int)depth >= sizeof spaces) {
+ depth = sizeof spaces - 1;
+ }
+
+ /*
+ * Log the view name unless it's:
+ * * "_default/IN" (which means there's only one view
+ * configured in the server), or
+ * * "_dnsclient/IN" (which means this is being called
+ * from an application using dns/client.c).
+ */
+ if (val->view->rdclass == dns_rdataclass_in &&
+ (strcmp(val->view->name, "_default") == 0 ||
+ strcmp(val->view->name, DNS_CLIENTVIEW_NAME) == 0))
+ {
+ sep1 = viewname = sep2 = "";
+ } else {
+ sep1 = "view ";
+ viewname = val->view->name;
+ sep2 = ": ";
+ }
+
+ if (val->event != NULL && val->event->name != NULL) {
+ char namebuf[DNS_NAME_FORMATSIZE];
+ char typebuf[DNS_RDATATYPE_FORMATSIZE];
+
+ dns_name_format(val->event->name, namebuf, sizeof(namebuf));
+ dns_rdatatype_format(val->event->type, typebuf,
+ sizeof(typebuf));
+ isc_log_write(dns_lctx, category, module, level,
+ "%s%s%s%.*svalidating %s/%s: %s", sep1, viewname,
+ sep2, depth, spaces, namebuf, typebuf, msgbuf);
+ } else {
+ isc_log_write(dns_lctx, category, module, level,
+ "%s%s%s%.*svalidator @%p: %s", sep1, viewname,
+ sep2, depth, spaces, val, msgbuf);
+ }
+}
+
+static void
+validator_log(void *val, int level, const char *fmt, ...) {
+ va_list ap;
+
+ if (!isc_log_wouldlog(dns_lctx, level)) {
+ return;
+ }
+
+ va_start(ap, fmt);
+
+ validator_logv(val, DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_VALIDATOR,
+ level, fmt, ap);
+ va_end(ap);
+}
+
+static void
+validator_logcreate(dns_validator_t *val, dns_name_t *name,
+ dns_rdatatype_t type, const char *caller,
+ const char *operation) {
+ char namestr[DNS_NAME_FORMATSIZE];
+ char typestr[DNS_RDATATYPE_FORMATSIZE];
+
+ dns_name_format(name, namestr, sizeof(namestr));
+ dns_rdatatype_format(type, typestr, sizeof(typestr));
+ validator_log(val, ISC_LOG_DEBUG(9), "%s: creating %s for %s %s",
+ caller, operation, namestr, typestr);
+}