validator.c revision 40f53fa8d9c6a4fc38c0014495e7a42b08f52481
/*
* Copyright (C) 2000 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: validator.c,v 1.71 2000/08/01 01:23:04 tale Exp $ */
#include <config.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/task.h>
#include <isc/util.h>
#include <dns/db.h>
#include <dns/dnssec.h>
#include <dns/events.h>
#include <dns/keytable.h>
#include <dns/log.h>
#include <dns/message.h>
#include <dns/nxt.h>
#include <dns/rdata.h>
#include <dns/rdatastruct.h>
#include <dns/rdataset.h>
#include <dns/rdatatype.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/validator.h>
#include <dns/view.h>
struct dns_validator {
/* Unlocked. */
unsigned int magic;
isc_mutex_t lock;
dns_view_t * view;
/* Locked by lock. */
unsigned int options;
unsigned int attributes;
dns_validatorevent_t * event;
dns_fetch_t * fetch;
dns_validator_t * keyvalidator;
dns_validator_t * authvalidator;
dns_keytable_t * keytable;
dns_keynode_t * keynode;
dst_key_t * key;
dns_rdata_sig_t * siginfo;
isc_task_t * task;
isc_taskaction_t action;
void * arg;
unsigned int labels;
dns_rdataset_t * currentset;
isc_boolean_t seensig;
dns_rdataset_t * keyset;
dns_rdataset_t frdataset;
dns_rdataset_t fsigrdataset;
};
#define VALIDATOR_MAGIC 0x56616c3fU /* Val?. */
#define VALID_VALIDATOR(v) ISC_MAGIC_VALID(v, VALIDATOR_MAGIC)
#define VALATTR_SHUTDOWN 0x01
#define VALATTR_FOUNDNONEXISTENCE 0x02
#define VALATTR_TRIEDVERIFY 0x04
#define SHUTDOWN(v) (((v)->attributes & VALATTR_SHUTDOWN) != 0)
static void
nullkeyvalidated(isc_task_t *task, isc_event_t *event);
static inline isc_boolean_t
containsnullkey(dns_validator_t *val, dns_rdataset_t *rdataset);
static inline isc_result_t
get_dst_key(dns_validator_t *val, dns_rdata_sig_t *siginfo,
dns_rdataset_t *rdataset);
static inline isc_result_t
validate(dns_validator_t *val, isc_boolean_t resume);
static inline isc_result_t
nxtvalidate(dns_validator_t *val, isc_boolean_t resume);
static inline isc_result_t
proveunsecure(dns_validator_t *val, isc_boolean_t resume);
static void
validator_log(dns_validator_t *val, int level, const char *fmt, ...);
static void
validator_done(dns_validator_t *val, isc_result_t result) {
isc_task_t *task;
REQUIRE(val->event != NULL);
/*
* 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);
}
static void
auth_nonpending(dns_message_t *message) {
isc_result_t result;
dns_name_t *name;
dns_rdataset_t *rdataset;
for (result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
result == ISC_R_SUCCESS;
result = dns_message_nextname(message, DNS_SECTION_AUTHORITY))
{
name = NULL;
dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
for (rdataset = ISC_LIST_HEAD(name->list);
rdataset != NULL;
rdataset = ISC_LIST_NEXT(rdataset, link))
{
if (rdataset->trust == dns_trust_pending)
rdataset->trust = dns_trust_authauthority;
}
}
}
static void
fetch_callback_validator(isc_task_t *task, isc_event_t *event) {
dns_fetchevent_t *devent;
dns_validator_t *val;
dns_rdataset_t *rdataset;
isc_result_t result;
isc_result_t eresult;
UNUSED(task);
INSIST(event->ev_type == DNS_EVENT_FETCHDONE);
devent = (dns_fetchevent_t *)event;
val = devent->ev_arg;
rdataset = &val->frdataset;
eresult = devent->result;
isc_event_free(&event);
dns_resolver_destroyfetch(&val->fetch);
validator_log(val, ISC_LOG_DEBUG(3), "in fetch_callback_validator");
LOCK(&val->lock);
if (eresult == ISC_R_SUCCESS) {
validator_log(val, ISC_LOG_DEBUG(3),
"keyset with trust %d", rdataset->trust);
/*
* Only extract the dst key if the keyset is secure.
*/
if (rdataset->trust >= dns_trust_secure) {
result = get_dst_key(val, val->siginfo, rdataset);
if (result == ISC_R_SUCCESS)
val->keyset = &val->frdataset;
}
result = validate(val, ISC_TRUE);
if (result != DNS_R_WAIT) {
validator_done(val, result);
goto out;
}
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"fetch_callback_validator: got %s",
dns_result_totext(eresult));
validator_done(val, eresult);
}
out:
UNLOCK(&val->lock);
/*
* Free stuff from the event.
*/
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);
}
static void
fetch_callback_nullkey(isc_task_t *task, isc_event_t *event) {
dns_fetchevent_t *devent;
dns_validator_t *val;
dns_rdataset_t *rdataset, *sigrdataset;
dns_fetch_t *fetch;
isc_result_t result;
isc_result_t eresult;
UNUSED(task);
INSIST(event->ev_type == DNS_EVENT_FETCHDONE);
devent = (dns_fetchevent_t *)event;
val = devent->ev_arg;
rdataset = &val->frdataset;
sigrdataset = &val->fsigrdataset;
eresult = devent->result;
validator_log(val, ISC_LOG_DEBUG(3), "in fetch_callback_nullkey");
fetch = val->fetch;
val->fetch = NULL;
LOCK(&val->lock);
if (eresult == ISC_R_SUCCESS) {
if (!containsnullkey(val, rdataset)) {
/*
* No null key.
*/
validator_log(val, ISC_LOG_DEBUG(3),
"found a keyset, no null key");
result = proveunsecure(val, ISC_TRUE);
if (result != DNS_R_WAIT)
validator_done(val, result);
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"found a keyset with a null key");
if (rdataset->trust >= dns_trust_secure) {
validator_log(val, ISC_LOG_DEBUG(3),
"insecurity proof succeeded");
val->event->rdataset->trust = dns_trust_answer;
validator_done(val, ISC_R_SUCCESS);
} else if (!dns_rdataset_isassociated(sigrdataset)) {
validator_log(val, ISC_LOG_DEBUG(3),
"insecurity proof failed");
validator_done(val, DNS_R_NOTINSECURE);
} else {
dns_name_t *tname;
tname = dns_fixedname_name(&devent->foundname);
result = dns_validator_create(val->view, tname,
dns_rdatatype_key,
rdataset,
sigrdataset, NULL,
0, val->task,
nullkeyvalidated,
val,
&val->keyvalidator);
if (result != ISC_R_SUCCESS)
validator_done(val, result);
/*
* Don't free these, since they'll be
* freed in nullkeyvalidated.
*/
dns_resolver_destroyfetch(&fetch);
isc_event_free(&event);
UNLOCK(&val->lock);
return;
}
}
} else if (eresult == DNS_R_NCACHENXDOMAIN ||
eresult == DNS_R_NCACHENXRRSET ||
eresult == DNS_R_NXDOMAIN ||
eresult == DNS_R_NXRRSET)
{
/*
* No keys.
*/
validator_log(val, ISC_LOG_DEBUG(3),
"no keys found");
result = proveunsecure(val, ISC_TRUE);
if (result != DNS_R_WAIT)
validator_done(val, result);
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"fetch_callback_nullkey: got %s",
dns_result_totext(eresult));
validator_done(val, eresult);
}
UNLOCK(&val->lock);
dns_resolver_destroyfetch(&fetch);
/*
* Free stuff from the event.
*/
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
isc_event_free(&event);
}
static void
keyvalidated(isc_task_t *task, isc_event_t *event) {
dns_validatorevent_t *devent;
dns_validator_t *val;
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);
validator_log(val, ISC_LOG_DEBUG(3), "in keyvalidated");
LOCK(&val->lock);
if (eresult == ISC_R_SUCCESS) {
validator_log(val, ISC_LOG_DEBUG(3),
"keyset with trust %d", &val->frdataset.trust);
/*
* Only extract the dst key if the keyset is secure.
*/
if (val->frdataset.trust >= dns_trust_secure)
(void) get_dst_key(val, val->siginfo, &val->frdataset);
result = validate(val, ISC_TRUE);
if (result != DNS_R_WAIT) {
validator_done(val, result);
goto out;
}
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"keyvalidated: got %s",
dns_result_totext(eresult));
validator_done(val, eresult);
}
out:
UNLOCK(&val->lock);
dns_validator_destroy(&val->keyvalidator);
/*
* Free stuff from the event.
*/
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
}
static isc_boolean_t
nxtprovesnonexistence(dns_validator_t *val, dns_name_t *nxtname,
dns_rdataset_t *nxtset, dns_rdataset_t *signxtset)
{
int order;
dns_rdata_t rdata;
isc_region_t r;
dns_name_t nextname;
isc_result_t result;
result = dns_rdataset_first(nxtset);
INSIST(result == ISC_R_SUCCESS);
dns_rdataset_current(nxtset, &rdata);
validator_log(val, ISC_LOG_DEBUG(3),
"looking for relevant nxt");
order = dns_name_compare(val->event->name, nxtname);
if (order == 0) {
/*
* The names are the same, so look for the type present bit.
*/
if (val->event->type >= 128) {
validator_log(val, ISC_LOG_DEBUG(3), "invalid type %d",
val->event->type);
return (ISC_FALSE);
}
if (dns_nxt_typepresent(&rdata, val->event->type)) {
validator_log(val, ISC_LOG_DEBUG(3),
"type should not be present");
return (ISC_FALSE);
}
validator_log(val, ISC_LOG_DEBUG(3), "nxt bitmask ok");
} else if (order > 0) {
/*
* The NXT owner name is less than the nonexistent name.
*/
dns_rdata_toregion(&rdata, &r);
dns_name_init(&nextname, NULL);
dns_name_fromregion(&nextname, &r);
order = dns_name_compare(val->event->name, &nextname);
if (order >= 0) {
/*
* The NXT next name is less than the nonexistent
* name. This is only ok if the next name is the zone
* name.
*/
dns_rdata_sig_t siginfo;
result = dns_rdataset_first(signxtset);
INSIST (result == ISC_R_SUCCESS);
dns_rdataset_current(signxtset, &rdata);
result = dns_rdata_tostruct(&rdata, &siginfo, NULL);
INSIST (result == ISC_R_SUCCESS);
if (!dns_name_equal(&siginfo.signer, &nextname)) {
validator_log(val, ISC_LOG_DEBUG(3),
"next name is not greater");
return (ISC_FALSE);
}
validator_log(val, ISC_LOG_DEBUG(3),
"nxt points to zone apex, ok");
}
validator_log(val, ISC_LOG_DEBUG(3),
"nxt range ok");
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"nxt owner name is not less");
/*
* The NXT owner name is greater than the supposedly
* nonexistent name. This NXT is irrelevant.
*/
return (ISC_FALSE);
}
return (ISC_TRUE);
}
static void
authvalidated(isc_task_t *task, isc_event_t *event) {
dns_validatorevent_t *devent;
dns_validator_t *val;
dns_rdataset_t *rdataset, *sigrdataset;
isc_result_t result;
isc_result_t eresult;
UNUSED(task);
INSIST(event->ev_type == DNS_EVENT_VALIDATORDONE);
devent = (dns_validatorevent_t *)event;
rdataset = devent->rdataset;
sigrdataset = devent->sigrdataset;
val = devent->ev_arg;
eresult = devent->result;
dns_validator_destroy(&val->authvalidator);
validator_log(val, ISC_LOG_DEBUG(3), "in authvalidated");
LOCK(&val->lock);
if (eresult != ISC_R_SUCCESS) {
validator_log(val, ISC_LOG_DEBUG(3),
"authvalidated: got %s",
dns_result_totext(eresult));
result = nxtvalidate(val, ISC_TRUE);
if (result != DNS_R_WAIT)
validator_done(val, result);
} else {
if (rdataset->type == dns_rdatatype_nxt &&
nxtprovesnonexistence(val, devent->name, rdataset,
sigrdataset))
val->attributes |= VALATTR_FOUNDNONEXISTENCE;
result = nxtvalidate(val, ISC_TRUE);
if (result != DNS_R_WAIT)
validator_done(val, result);
}
UNLOCK(&val->lock);
/*
* Free stuff from the event.
*/
isc_event_free(&event);
}
static void
negauthvalidated(isc_task_t *task, isc_event_t *event) {
dns_validatorevent_t *devent;
dns_validator_t *val;
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->authvalidator);
validator_log(val, ISC_LOG_DEBUG(3), "in negauthvalidated");
LOCK(&val->lock);
if (eresult == ISC_R_SUCCESS) {
val->attributes |= VALATTR_FOUNDNONEXISTENCE;
validator_log(val, ISC_LOG_DEBUG(3),
"nonexistence proof found");
auth_nonpending(val->event->message);
validator_done(val, ISC_R_SUCCESS);
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"negauthvalidated: got %s",
dns_result_totext(eresult));
validator_done(val, eresult);
}
UNLOCK(&val->lock);
/*
* Free stuff from the event.
*/
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
}
static void
nullkeyvalidated(isc_task_t *task, isc_event_t *event) {
dns_validatorevent_t *devent;
dns_validator_t *val;
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;
dns_name_free(devent->name, val->view->mctx);
isc_mem_put(val->view->mctx, devent->name, sizeof(dns_name_t));
isc_event_free(&event);
validator_log(val, ISC_LOG_DEBUG(3), "in nullkeyvalidated");
if (eresult == ISC_R_SUCCESS) {
validator_log(val, ISC_LOG_DEBUG(3),
"proved that name is in an unsecure domain");
LOCK(&val->lock);
validator_done(val, ISC_R_SUCCESS);
UNLOCK(&val->lock);
} else {
LOCK(&val->lock);
result = proveunsecure(val, ISC_TRUE);
if (result != DNS_R_WAIT)
validator_done(val, result);
UNLOCK(&val->lock);
}
dns_validator_destroy(&val->keyvalidator);
/*
* Free stuff from the event.
*/
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
}
/*
* Try to find a null zone key among those in 'rdataset'. If found, build
* a dst_key_t for it and point val->key at it.
*/
static inline isc_boolean_t
containsnullkey(dns_validator_t *val, dns_rdataset_t *rdataset) {
isc_result_t result;
dst_key_t *key = NULL;
isc_buffer_t b;
dns_rdata_t rdata;
isc_boolean_t found = ISC_FALSE;
result = dns_rdataset_first(rdataset);
if (result != ISC_R_SUCCESS)
return (ISC_FALSE);
while (result == ISC_R_SUCCESS && !found) {
dns_rdataset_current(rdataset, &rdata);
isc_buffer_init(&b, rdata.data, rdata.length);
isc_buffer_add(&b, rdata.length);
key = NULL;
/*
* The key name is unimportant, so we can avoid any name/text
* conversion.
*/
result = dst_key_fromdns(dns_rootname, &b, val->view->mctx,
&key);
if (result != ISC_R_SUCCESS)
continue;
if (dst_key_isnullkey(key))
found = ISC_TRUE;
dst_key_free(&key);
result = dns_rdataset_next(rdataset);
}
return (found);
}
/*
* Try to find a key that could have signed 'siginfo' among those
* in 'rdataset'. If found, build a dst_key_t for it and point
* val->key at it.
*
* If val->key is non-NULL, this returns the next matching key.
*/
static inline isc_result_t
get_dst_key(dns_validator_t *val, dns_rdata_sig_t *siginfo,
dns_rdataset_t *rdataset)
{
isc_result_t result;
isc_buffer_t b;
dns_rdata_t rdata;
dst_key_t *oldkey = val->key;
isc_boolean_t foundold;
if (oldkey == NULL)
foundold = ISC_TRUE;
else {
foundold = ISC_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, &b, val->view->mctx,
&val->key);
if (result != ISC_R_SUCCESS)
goto failure;
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) == ISC_TRUE)
{
foundold = ISC_TRUE;
dst_key_free(&oldkey);
}
}
dst_key_free(&val->key);
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);
}
static inline isc_result_t
get_key(dns_validator_t *val, dns_rdata_sig_t *siginfo) {
isc_result_t result;
dns_validatorevent_t *event;
unsigned int nbits, nlabels;
int order;
dns_namereln_t namereln;
event = val->event;
/*
* Is the key name appropriate for this signature?
*/
namereln = dns_name_fullcompare(event->name, &siginfo->signer,
&order, &nlabels, &nbits);
if (event->rdataset->type == dns_rdatatype_key &&
namereln != dns_namereln_subdomain) {
/*
* We don't want a KEY RR to authenticate
* itself, so we ignore the signature if it
* was not made by an ancestor of the KEY.
*/
return (DNS_R_CONTINUE);
} else if (namereln != dns_namereln_subdomain &&
namereln != dns_namereln_equal) {
/*
* The key name is not at the same level
* as 'rdataset', nor is it closer to the
* DNS root.
*/
return (DNS_R_CONTINUE);
}
/*
* Is the key used for the signature a security root?
*/
INSIST(val->keynode == NULL);
val->keytable = val->view->secroots;
result = dns_keytable_findkeynode(val->view->secroots,
&siginfo->signer,
siginfo->algorithm, siginfo->keyid,
&val->keynode);
if (result == ISC_R_SUCCESS) {
/*
* The key is a security root.
*/
val->key = dns_keynode_key(val->keynode);
return (ISC_R_SUCCESS);
}
/*
* Do we know about this key?
*/
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
result = dns_view_simplefind(val->view, &siginfo->signer,
dns_rdatatype_key, 0,
DNS_DBFIND_PENDINGOK, ISC_FALSE,
&val->frdataset, &val->fsigrdataset);
if (result == ISC_R_SUCCESS) {
/*
* We have an rrset for the given keyname.
*/
val->keyset = &val->frdataset;
if (val->frdataset.trust == dns_trust_pending &&
dns_rdataset_isassociated(&val->fsigrdataset))
{
/*
* We know the key but haven't validated it yet.
*/
result = dns_validator_create(val->view,
&siginfo->signer,
dns_rdatatype_key,
&val->frdataset,
&val->fsigrdataset,
NULL,
0,
val->task,
keyvalidated,
val,
&val->keyvalidator);
if (result != ISC_R_SUCCESS)
return (result);
return (DNS_R_WAIT);
} else if (val->frdataset.trust == dns_trust_pending) {
/*
* 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 %d",
val->frdataset.trust);
result = get_dst_key(val, siginfo, 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;
}
}
} else if (result == ISC_R_NOTFOUND) {
/*
* We don't know anything about this key.
*/
val->fetch = NULL;
result = dns_resolver_createfetch(val->view->resolver,
&siginfo->signer,
dns_rdatatype_key,
NULL, NULL, NULL, 0,
val->event->ev_sender,
fetch_callback_validator,
val,
&val->frdataset,
&val->fsigrdataset,
&val->fetch);
if (result != ISC_R_SUCCESS)
return (result);
return (DNS_R_WAIT);
} else if (result == DNS_R_NCACHENXDOMAIN ||
result == DNS_R_NCACHENXRRSET ||
result == DNS_R_NXDOMAIN ||
result == DNS_R_NXRRSET)
{
/*
* This key doesn't exist.
*/
result = DNS_R_CONTINUE;
}
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);
}
/*
* If the rdataset being validated is a key set, is each key a security root?
*/
static isc_boolean_t
issecurityroot(dns_validator_t *val) {
dns_name_t *name;
dns_rdataset_t *rdataset;
isc_mem_t *mctx;
dns_keytable_t *secroots;
dns_rdata_t rdata;
isc_result_t result;
dns_keynode_t *keynode, *nextnode;
dst_key_t *key, *secrootkey;
isc_boolean_t match = ISC_FALSE;
name = val->event->name;
rdataset = val->event->rdataset;
mctx = val->view->mctx;
secroots = val->view->secroots;
for (result = dns_rdataset_first(rdataset);
result == ISC_R_SUCCESS;
result = dns_rdataset_next(rdataset))
{
dns_rdataset_current(rdataset, &rdata);
key = NULL;
result = dns_dnssec_keyfromrdata(name, &rdata, mctx, &key);
if (result != ISC_R_SUCCESS)
continue;
keynode = NULL;
result = dns_keytable_findkeynode(secroots, name,
dst_key_alg(key),
dst_key_id(key),
&keynode);
match = ISC_FALSE;
while (result == ISC_R_SUCCESS) {
secrootkey = dns_keynode_key(keynode);
if (dst_key_compare(key, secrootkey)) {
match = ISC_TRUE;
dns_keytable_detachkeynode(secroots, &keynode);
break;
}
nextnode = NULL;
result = dns_keytable_findnextkeynode(secroots,
keynode,
&nextnode);
dns_keytable_detachkeynode(secroots, &keynode);
}
dst_key_free(&key);
if (!match)
return (ISC_FALSE);
}
return (match);
}
/*
* Attempts positive response validation.
*
* Returns:
* ISC_R_SUCCESS Validation completed successfully
* DNS_R_WAIT Validation has started but is waiting
* for an event.
* Other return codes are possible and all indicate failure.
*/
static inline isc_result_t
validate(dns_validator_t *val, isc_boolean_t resume) {
isc_result_t result;
dns_validatorevent_t *event;
dns_rdata_t rdata;
/*
* Caller must be holding the validator lock.
*/
event = val->event;
/*
* If this is a security root, it's ok.
*/
if (!resume) {
dns_fixedname_t fsecroot;
dns_name_t *secroot;
dns_fixedname_init(&fsecroot);
secroot = dns_fixedname_name(&fsecroot);
result = dns_keytable_finddeepestmatch(val->view->secroots,
val->event->name,
secroot);
if (result == ISC_R_SUCCESS &&
val->event->type == dns_rdatatype_key &&
dns_name_equal(val->event->name, secroot) &&
issecurityroot(val))
{
val->event->rdataset->trust = dns_trust_secure;
return (ISC_R_SUCCESS);
}
}
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_rdataset_current(event->sigrdataset, &rdata);
if (val->siginfo != NULL)
isc_mem_put(val->view->mctx, val->siginfo,
sizeof *val->siginfo);
val->siginfo = isc_mem_get(val->view->mctx,
sizeof *val->siginfo);
if (val->siginfo == NULL)
return (ISC_R_NOMEMORY);
dns_rdata_tostruct(&rdata, val->siginfo, NULL);
/*
* At this point we could check that the signature algorithm
* was known and "sufficiently good". For now, any algorithm
* is acceptable.
*/
if (!resume) {
result = get_key(val, val->siginfo);
if (result == DNS_R_CONTINUE)
continue; /* Try the next SIG RR. */
if (result != ISC_R_SUCCESS)
return (result);
}
if (val->key == NULL) {
event->rdataset->trust = dns_trust_answer;
event->sigrdataset->trust = dns_trust_answer;
validator_log(val, ISC_LOG_DEBUG(3),
"marking as answer");
return (ISC_R_SUCCESS);
}
do {
val->attributes |= VALATTR_TRIEDVERIFY;
result = dns_dnssec_verify(event->name,
event->rdataset,
val->key, ISC_FALSE,
val->view->mctx, &rdata);
validator_log(val, ISC_LOG_DEBUG(3),
"verify rdataset: %s",
isc_result_totext(result));
if (result == ISC_R_SUCCESS)
break;
if (val->keynode != NULL) {
dns_keynode_t *nextnode = NULL;
result = dns_keytable_findnextkeynode(
val->keytable,
val->keynode,
&nextnode);
dns_keytable_detachkeynode(val->keytable,
&val->keynode);
val->keynode = nextnode;
if (result != ISC_R_SUCCESS) {
val->key = NULL;
break;
}
val->key = dns_keynode_key(val->keynode);
} else {
if (get_dst_key(val, val->siginfo, val->keyset)
!= ISC_R_SUCCESS)
break;
}
} while (1);
if (result != ISC_R_SUCCESS)
validator_log(val, ISC_LOG_DEBUG(3),
"failed to verify rdataset");
else {
isc_uint32_t ttl;
isc_stdtime_t now;
isc_stdtime_get(&now);
ttl = ISC_MIN(event->rdataset->ttl,
val->siginfo->timeexpire - now);
if (val->keyset != NULL)
ttl = ISC_MIN(ttl, val->keyset->ttl);
event->rdataset->ttl = ttl;
event->sigrdataset->ttl = ttl;
}
if (val->keynode != NULL)
dns_keytable_detachkeynode(val->keytable,
&val->keynode);
else {
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 (result == ISC_R_SUCCESS) {
event->rdataset->trust = dns_trust_secure;
event->sigrdataset->trust = dns_trust_secure;
validator_log(val, ISC_LOG_DEBUG(3),
"marking as secure");
return (result);
}
else
validator_log(val, ISC_LOG_DEBUG(3),
"verify failure: %s",
isc_result_totext(result));
}
INSIST(result == ISC_R_NOMORE);
validator_log(val, ISC_LOG_INFO, "no valid signature found");
return (DNS_R_NOVALIDSIG);
}
static inline isc_result_t
nxtvalidate(dns_validator_t *val, isc_boolean_t 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);
if (result != ISC_R_SUCCESS)
validator_done(val, ISC_R_NOTFOUND);
} else {
result = ISC_R_SUCCESS;
validator_log(val, ISC_LOG_DEBUG(3), "resuming nxtvalidate");
}
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 = ISC_FALSE;
}
else
rdataset = ISC_LIST_HEAD(name->list);
for (;
rdataset != NULL;
rdataset = ISC_LIST_NEXT(rdataset, link))
{
if (rdataset->type == dns_rdatatype_sig)
continue;
for (sigrdataset = ISC_LIST_HEAD(name->list);
sigrdataset != NULL;
sigrdataset = ISC_LIST_NEXT(sigrdataset,
link))
{
if (sigrdataset->type == dns_rdatatype_sig &&
sigrdataset->covers == rdataset->type)
break;
}
if (sigrdataset == NULL)
continue;
val->seensig = ISC_TRUE;
val->authvalidator = NULL;
val->currentset = rdataset;
result = dns_validator_create(val->view, name,
rdataset->type,
rdataset,
sigrdataset,
NULL, 0,
val->task,
authvalidated,
val,
&val->authvalidator);
if (result != ISC_R_SUCCESS)
return (result);
return (DNS_R_WAIT);
}
}
if (result == ISC_R_NOMORE)
result = ISC_R_SUCCESS;
if (result != ISC_R_SUCCESS)
validator_done(val, result);
if ((val->attributes & VALATTR_FOUNDNONEXISTENCE) == 0) {
if (!val->seensig) {
result = dns_validator_create(val->view, name,
dns_rdatatype_soa,
&val->frdataset,
NULL, NULL, 0,
val->task,
negauthvalidated,
val,
&val->authvalidator);
if (result != ISC_R_SUCCESS)
return (result);
return (DNS_R_WAIT);
}
validator_log(val, ISC_LOG_DEBUG(3),
"nonexistence proof not found");
return (DNS_R_NOVALIDNXT);
} else {
validator_log(val, ISC_LOG_DEBUG(3),
"nonexistence proof found");
return (ISC_R_SUCCESS);
}
}
static inline isc_result_t
proveunsecure(dns_validator_t *val, isc_boolean_t resume) {
isc_result_t result;
dns_fixedname_t secroot, tfname;
dns_name_t *tname;
dns_fixedname_init(&secroot);
dns_fixedname_init(&tfname);
result = dns_keytable_finddeepestmatch(val->view->secroots,
val->event->name,
dns_fixedname_name(&secroot));
/*
* If the name is not under a security root, it must be insecure.
*/
if (result == ISC_R_NOTFOUND)
return (ISC_R_SUCCESS);
else if (result != ISC_R_SUCCESS)
return (result);
/*
* If this is a security root, it's ok.
*/
if (val->event->type == dns_rdatatype_key &&
dns_name_equal(val->event->name, dns_fixedname_name(&secroot)) &&
issecurityroot(val))
{
val->event->rdataset->trust = dns_trust_secure;
return (ISC_R_SUCCESS);
}
if (!resume)
val->labels = dns_name_depth(dns_fixedname_name(&secroot)) + 1;
else {
validator_log(val, ISC_LOG_DEBUG(3), "resuming proveunsecure");
val->labels++;
}
for (;
val->labels <= dns_name_depth(val->event->name);
val->labels++)
{
char namebuf[1024];
if (val->labels == dns_name_depth(val->event->name)) {
if (val->event->type == dns_rdatatype_key)
break;
tname = val->event->name;
} else {
tname = dns_fixedname_name(&tfname);
result = dns_name_splitatdepth(val->event->name,
val->labels,
NULL, tname);
if (result != ISC_R_SUCCESS)
return (result);
}
dns_name_format(tname, namebuf, sizeof(namebuf));
validator_log(val, ISC_LOG_DEBUG(3),
"looking for null keyset at '%s'",
namebuf);
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
result = dns_view_simplefind(val->view, tname,
dns_rdatatype_key, 0,
DNS_DBFIND_PENDINGOK, ISC_FALSE,
&val->frdataset,
&val->fsigrdataset);
if (result == ISC_R_SUCCESS) {
dns_name_t *fname = NULL;
if (!dns_rdataset_isassociated(&val->fsigrdataset)) {
result = DNS_R_NOTINSECURE;
goto out;
}
validator_log(val, ISC_LOG_DEBUG(3),
"found keyset, looking for null key");
if (!containsnullkey(val, &val->frdataset))
continue;
if (val->frdataset.trust >= dns_trust_secure) {
validator_log(val, ISC_LOG_DEBUG(3),
"insecurity proof succeeded");
val->event->rdataset->trust = dns_trust_answer;
result = ISC_R_SUCCESS;
goto out;
}
fname = isc_mem_get(val->view->mctx, sizeof *fname);
if (fname == NULL)
return (ISC_R_NOMEMORY);
dns_name_init(fname, NULL);
result = dns_name_dup(tname, val->view->mctx, fname);
if (result != ISC_R_SUCCESS) {
isc_mem_put(val->view->mctx, fname,
sizeof *fname);
result = ISC_R_NOMEMORY;
goto out;
}
result = dns_validator_create(val->view,
fname,
dns_rdatatype_key,
&val->frdataset,
&val->fsigrdataset,
NULL,
0,
val->task,
nullkeyvalidated,
val,
&val->keyvalidator);
if (result != ISC_R_SUCCESS)
goto out;
return (DNS_R_WAIT);
} else if (result == ISC_R_NOTFOUND) {
val->fetch = NULL;
result = dns_resolver_createfetch(val->view->resolver,
tname,
dns_rdatatype_key,
NULL, NULL, NULL, 0,
val->event->ev_sender,
fetch_callback_nullkey,
val,
&val->frdataset,
&val->fsigrdataset,
&val->fetch);
if (result != ISC_R_SUCCESS)
goto out;
return (DNS_R_WAIT);
} else if (result == DNS_R_NCACHENXDOMAIN ||
result == DNS_R_NCACHENXRRSET ||
result == DNS_R_NXDOMAIN ||
result == DNS_R_NXRRSET)
{
continue;
} else
goto out;
}
validator_log(val, ISC_LOG_DEBUG(3), "insecurity proof failed");
return (DNS_R_NOTINSECURE); /* Didn't find a null key */
out:
if (dns_rdataset_isassociated(&val->frdataset))
dns_rdataset_disassociate(&val->frdataset);
if (dns_rdataset_isassociated(&val->fsigrdataset))
dns_rdataset_disassociate(&val->fsigrdataset);
return (result);
}
static void
validator_start(isc_task_t *task, isc_event_t *event) {
dns_validator_t *val;
dns_validatorevent_t *vevent;
isc_result_t result = ISC_R_FAILURE;
UNUSED(task);
REQUIRE(event->ev_type == DNS_EVENT_VALIDATORSTART);
vevent = (dns_validatorevent_t *)event;
val = vevent->validator;
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 we don't know if wildcards are involved yet so it
* could still get complicated.
*/
validator_log(val, ISC_LOG_DEBUG(3),
"attempting positive response validation");
result = validate(val, ISC_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, ISC_FALSE);
if (result == DNS_R_NOTINSECURE)
result = saved_result;
}
} else if (val->event->rdataset != NULL) {
/*
* This is either an unsecure subdomain or a response from
* a broken server.
*/
validator_log(val, ISC_LOG_DEBUG(3),
"attempting insecurity proof");
result = proveunsecure(val, ISC_FALSE);
} else if (val->event->rdataset == NULL &&
val->event->sigrdataset == NULL)
{
/*
* This is a nonexistence validation.
*/
validator_log(val, ISC_LOG_DEBUG(3),
"attempting negative response validation");
result = nxtvalidate(val, ISC_FALSE);
} else {
/*
* This shouldn't happen.
*/
INSIST(0);
}
if (result != DNS_R_WAIT)
validator_done(val, result);
UNLOCK(&val->lock);
}
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;
dns_validator_t *val;
isc_task_t *tclone;
dns_validatorevent_t *event;
REQUIRE(name != NULL);
REQUIRE(type != 0);
REQUIRE(rdataset != NULL ||
(rdataset == NULL && sigrdataset == NULL && message != NULL));
REQUIRE(options == 0);
REQUIRE(validatorp != NULL && *validatorp == NULL);
tclone = NULL;
result = ISC_R_FAILURE;
val = isc_mem_get(view->mctx, sizeof *val);
if (val == NULL)
return (ISC_R_NOMEMORY);
val->view = NULL;
dns_view_attach(view, &val->view);
event = (dns_validatorevent_t *)
isc_event_allocate(view->mctx, task,
DNS_EVENT_VALIDATORSTART,
validator_start, NULL,
sizeof (dns_validatorevent_t));
if (event == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup_val;
}
isc_task_attach(task, &tclone);
event->validator = val;
event->result = ISC_R_FAILURE;
event->name = name;
event->type = type;
event->rdataset = rdataset;
event->sigrdataset = sigrdataset;
event->message = message;
result = isc_mutex_init(&val->lock);
if (result != ISC_R_SUCCESS)
goto cleanup_event;
val->event = event;
val->options = options;
val->attributes = 0;
val->fetch = NULL;
val->keyvalidator = NULL;
val->authvalidator = NULL;
val->keynode = NULL;
val->key = NULL;
val->siginfo = NULL;
val->task = task;
val->action = action;
val->arg = arg;
val->labels = 0;
val->currentset = NULL;
val->keyset = NULL;
val->seensig = ISC_FALSE;
dns_rdataset_init(&val->frdataset);
dns_rdataset_init(&val->fsigrdataset);
val->magic = VALIDATOR_MAGIC;
isc_task_send(task, (isc_event_t **)&event);
*validatorp = val;
return (ISC_R_SUCCESS);
cleanup_event:
isc_task_detach(&tclone);
isc_event_free((isc_event_t **)&val->event);
cleanup_val:
dns_view_detach(&val->view);
isc_mem_put(view->mctx, val, sizeof *val);
return (result);
}
void
dns_validator_cancel(dns_validator_t *validator) {
isc_task_t *task;
REQUIRE(VALID_VALIDATOR(validator));
LOCK(&validator->lock);
if (validator->event != NULL) {
validator->event->result = ISC_R_CANCELED;
task = validator->event->ev_sender;
validator->event->ev_sender = validator;
isc_task_sendanddetach(&task,
(isc_event_t **)&validator->event);
if (validator->fetch != NULL)
dns_resolver_cancelfetch(validator->fetch);
if (validator->keyvalidator != NULL)
dns_validator_cancel(validator->keyvalidator);
}
UNLOCK(&validator->lock);
}
static void
destroy(dns_validator_t *val) {
isc_mem_t *mctx;
REQUIRE(SHUTDOWN(val));
REQUIRE(val->event == NULL);
REQUIRE(val->fetch == NULL);
#if 0
REQUIRE(val->currentset == NULL);
#endif
if (val->keynode != NULL)
dns_keytable_detachkeynode(val->keytable, &val->keynode);
else if (val->key != NULL)
dst_key_free(&val->key);
if (val->keyvalidator != NULL)
dns_validator_destroy(&val->keyvalidator);
if (val->authvalidator != NULL)
dns_validator_destroy(&val->authvalidator);
mctx = val->view->mctx;
if (val->siginfo != NULL)
isc_mem_put(mctx, val->siginfo, sizeof *val->siginfo);
isc_mutex_destroy(&val->lock);
dns_view_detach(&val->view);
val->magic = 0;
isc_mem_put(mctx, val, sizeof *val);
}
void
dns_validator_destroy(dns_validator_t **validatorp) {
dns_validator_t *val;
isc_boolean_t want_destroy = ISC_FALSE;
REQUIRE(validatorp != NULL);
val = *validatorp;
REQUIRE(VALID_VALIDATOR(val));
LOCK(&val->lock);
REQUIRE(val->event == NULL);
val->attributes |= VALATTR_SHUTDOWN;
if (val->fetch == NULL)
want_destroy = ISC_TRUE;
UNLOCK(&val->lock);
if (want_destroy)
destroy(val);
*validatorp = NULL;
}
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];
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
if (val->event != NULL && val->event->name != NULL) {
char namebuf[1024];
char typebuf[256];
isc_buffer_t b;
isc_region_t r;
dns_name_format(val->event->name, namebuf, sizeof(namebuf));
isc_buffer_init(&b, (unsigned char *)typebuf, sizeof(typebuf));
if (dns_rdatatype_totext(val->event->type, &b)
!= ISC_R_SUCCESS)
{
isc_buffer_clear(&b);
isc_buffer_putstr(&b, "<bad type>");
}
isc_buffer_usedregion(&b, &r);
isc_log_write(dns_lctx, category, module, level,
"validating %s %.*s: %s", namebuf,
(int)r.length, (char *)r.base, msgbuf);
} else {
isc_log_write(dns_lctx, category, module, level,
"validator @%p: %s", val, msgbuf);
}
}
static void
validator_log(dns_validator_t *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);
}