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wownero/external/unbound/validator/validator.c
Riccardo Spagni 831933425b
update unbound from upstream
2014-12-04 23:10:49 +02:00

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/*
* validator/validator.c - secure validator DNS query response module
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains a module that performs validation of DNS queries.
* According to RFC 4034.
*/
#include "config.h"
#include "validator/validator.h"
#include "validator/val_anchor.h"
#include "validator/val_kcache.h"
#include "validator/val_kentry.h"
#include "validator/val_utils.h"
#include "validator/val_nsec.h"
#include "validator/val_nsec3.h"
#include "validator/val_neg.h"
#include "validator/val_sigcrypt.h"
#include "validator/autotrust.h"
#include "services/cache/dns.h"
#include "util/data/dname.h"
#include "util/module.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/regional.h"
#include "util/config_file.h"
#include "util/fptr_wlist.h"
#include "ldns/rrdef.h"
#include "ldns/wire2str.h"
/* forward decl for cache response and normal super inform calls of a DS */
static void process_ds_response(struct module_qstate* qstate,
struct val_qstate* vq, int id, int rcode, struct dns_msg* msg,
struct query_info* qinfo, struct sock_list* origin);
/** fill up nsec3 key iterations config entry */
static int
fill_nsec3_iter(struct val_env* ve, char* s, int c)
{
char* e;
int i;
free(ve->nsec3_keysize);
free(ve->nsec3_maxiter);
ve->nsec3_keysize = (size_t*)calloc(sizeof(size_t), (size_t)c);
ve->nsec3_maxiter = (size_t*)calloc(sizeof(size_t), (size_t)c);
if(!ve->nsec3_keysize || !ve->nsec3_maxiter) {
log_err("out of memory");
return 0;
}
for(i=0; i<c; i++) {
ve->nsec3_keysize[i] = (size_t)strtol(s, &e, 10);
if(s == e) {
log_err("cannot parse: %s", s);
return 0;
}
s = e;
ve->nsec3_maxiter[i] = (size_t)strtol(s, &e, 10);
if(s == e) {
log_err("cannot parse: %s", s);
return 0;
}
s = e;
if(i>0 && ve->nsec3_keysize[i-1] >= ve->nsec3_keysize[i]) {
log_err("nsec3 key iterations not ascending: %d %d",
(int)ve->nsec3_keysize[i-1],
(int)ve->nsec3_keysize[i]);
return 0;
}
verbose(VERB_ALGO, "validator nsec3cfg keysz %d mxiter %d",
(int)ve->nsec3_keysize[i], (int)ve->nsec3_maxiter[i]);
}
return 1;
}
/** apply config settings to validator */
static int
val_apply_cfg(struct module_env* env, struct val_env* val_env,
struct config_file* cfg)
{
int c;
val_env->bogus_ttl = (uint32_t)cfg->bogus_ttl;
val_env->clean_additional = cfg->val_clean_additional;
val_env->permissive_mode = cfg->val_permissive_mode;
if(!env->anchors)
env->anchors = anchors_create();
if(!env->anchors) {
log_err("out of memory");
return 0;
}
if(!val_env->kcache)
val_env->kcache = key_cache_create(cfg);
if(!val_env->kcache) {
log_err("out of memory");
return 0;
}
env->key_cache = val_env->kcache;
if(!anchors_apply_cfg(env->anchors, cfg)) {
log_err("validator: error in trustanchors config");
return 0;
}
val_env->date_override = cfg->val_date_override;
val_env->skew_min = cfg->val_sig_skew_min;
val_env->skew_max = cfg->val_sig_skew_max;
c = cfg_count_numbers(cfg->val_nsec3_key_iterations);
if(c < 1 || (c&1)) {
log_err("validator: unparseable or odd nsec3 key "
"iterations: %s", cfg->val_nsec3_key_iterations);
return 0;
}
val_env->nsec3_keyiter_count = c/2;
if(!fill_nsec3_iter(val_env, cfg->val_nsec3_key_iterations, c/2)) {
log_err("validator: cannot apply nsec3 key iterations");
return 0;
}
if(!val_env->neg_cache)
val_env->neg_cache = val_neg_create(cfg,
val_env->nsec3_maxiter[val_env->nsec3_keyiter_count-1]);
if(!val_env->neg_cache) {
log_err("out of memory");
return 0;
}
env->neg_cache = val_env->neg_cache;
return 1;
}
int
val_init(struct module_env* env, int id)
{
struct val_env* val_env = (struct val_env*)calloc(1,
sizeof(struct val_env));
if(!val_env) {
log_err("malloc failure");
return 0;
}
env->modinfo[id] = (void*)val_env;
env->need_to_validate = 1;
val_env->permissive_mode = 0;
lock_basic_init(&val_env->bogus_lock);
lock_protect(&val_env->bogus_lock, &val_env->num_rrset_bogus,
sizeof(val_env->num_rrset_bogus));
if(!val_apply_cfg(env, val_env, env->cfg)) {
log_err("validator: could not apply configuration settings.");
return 0;
}
return 1;
}
void
val_deinit(struct module_env* env, int id)
{
struct val_env* val_env;
if(!env || !env->modinfo[id])
return;
val_env = (struct val_env*)env->modinfo[id];
lock_basic_destroy(&val_env->bogus_lock);
anchors_delete(env->anchors);
env->anchors = NULL;
key_cache_delete(val_env->kcache);
neg_cache_delete(val_env->neg_cache);
free(val_env->nsec3_keysize);
free(val_env->nsec3_maxiter);
free(val_env);
env->modinfo[id] = NULL;
}
/** fill in message structure */
static struct val_qstate*
val_new_getmsg(struct module_qstate* qstate, struct val_qstate* vq)
{
if(!qstate->return_msg || qstate->return_rcode != LDNS_RCODE_NOERROR) {
/* create a message to verify */
verbose(VERB_ALGO, "constructing reply for validation");
vq->orig_msg = (struct dns_msg*)regional_alloc(qstate->region,
sizeof(struct dns_msg));
if(!vq->orig_msg)
return NULL;
vq->orig_msg->qinfo = qstate->qinfo;
vq->orig_msg->rep = (struct reply_info*)regional_alloc(
qstate->region, sizeof(struct reply_info));
if(!vq->orig_msg->rep)
return NULL;
memset(vq->orig_msg->rep, 0, sizeof(struct reply_info));
vq->orig_msg->rep->flags = (uint16_t)(qstate->return_rcode&0xf)
|BIT_QR|BIT_RA|(qstate->query_flags|(BIT_CD|BIT_RD));
vq->orig_msg->rep->qdcount = 1;
} else {
vq->orig_msg = qstate->return_msg;
}
vq->qchase = qstate->qinfo;
/* chase reply will be an edited (sub)set of the orig msg rrset ptrs */
vq->chase_reply = regional_alloc_init(qstate->region,
vq->orig_msg->rep,
sizeof(struct reply_info) - sizeof(struct rrset_ref));
if(!vq->chase_reply)
return NULL;
vq->chase_reply->rrsets = regional_alloc_init(qstate->region,
vq->orig_msg->rep->rrsets, sizeof(struct ub_packed_rrset_key*)
* vq->orig_msg->rep->rrset_count);
if(!vq->chase_reply->rrsets)
return NULL;
vq->rrset_skip = 0;
return vq;
}
/** allocate new validator query state */
static struct val_qstate*
val_new(struct module_qstate* qstate, int id)
{
struct val_qstate* vq = (struct val_qstate*)regional_alloc(
qstate->region, sizeof(*vq));
log_assert(!qstate->minfo[id]);
if(!vq)
return NULL;
memset(vq, 0, sizeof(*vq));
qstate->minfo[id] = vq;
vq->state = VAL_INIT_STATE;
return val_new_getmsg(qstate, vq);
}
/**
* Exit validation with an error status
*
* @param qstate: query state
* @param id: validator id.
* @return false, for use by caller to return to stop processing.
*/
static int
val_error(struct module_qstate* qstate, int id)
{
qstate->ext_state[id] = module_error;
qstate->return_rcode = LDNS_RCODE_SERVFAIL;
return 0;
}
/**
* Check to see if a given response needs to go through the validation
* process. Typical reasons for this routine to return false are: CD bit was
* on in the original request, or the response is a kind of message that
* is unvalidatable (i.e., SERVFAIL, REFUSED, etc.)
*
* @param qstate: query state.
* @param ret_rc: rcode for this message (if noerror - examine ret_msg).
* @param ret_msg: return msg, can be NULL; look at rcode instead.
* @return true if the response could use validation (although this does not
* mean we can actually validate this response).
*/
static int
needs_validation(struct module_qstate* qstate, int ret_rc,
struct dns_msg* ret_msg)
{
int rcode;
/* If the CD bit is on in the original request, then you could think
* that we don't bother to validate anything.
* But this is signalled internally with the valrec flag.
* User queries are validated with BIT_CD to make our cache clean
* so that bogus messages get retried by the upstream also for
* downstream validators that set BIT_CD.
* For DNS64 bit_cd signals no dns64 processing, but we want to
* provide validation there too */
/*
if(qstate->query_flags & BIT_CD) {
verbose(VERB_ALGO, "not validating response due to CD bit");
return 0;
}
*/
if(qstate->is_valrec) {
verbose(VERB_ALGO, "not validating response, is valrec"
"(validation recursion lookup)");
return 0;
}
if(ret_rc != LDNS_RCODE_NOERROR || !ret_msg)
rcode = ret_rc;
else rcode = (int)FLAGS_GET_RCODE(ret_msg->rep->flags);
if(rcode != LDNS_RCODE_NOERROR && rcode != LDNS_RCODE_NXDOMAIN) {
if(verbosity >= VERB_ALGO) {
char rc[16];
rc[0]=0;
(void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
verbose(VERB_ALGO, "cannot validate non-answer, rcode %s", rc);
}
return 0;
}
/* cannot validate positive RRSIG response. (negatives can) */
if(qstate->qinfo.qtype == LDNS_RR_TYPE_RRSIG &&
rcode == LDNS_RCODE_NOERROR && ret_msg &&
ret_msg->rep->an_numrrsets > 0) {
verbose(VERB_ALGO, "cannot validate RRSIG, no sigs on sigs.");
return 0;
}
return 1;
}
/**
* Check to see if the response has already been validated.
* @param ret_msg: return msg, can be NULL
* @return true if the response has already been validated
*/
static int
already_validated(struct dns_msg* ret_msg)
{
/* validate unchecked, and re-validate bogus messages */
if (ret_msg && ret_msg->rep->security > sec_status_bogus)
{
verbose(VERB_ALGO, "response has already been validated: %s",
sec_status_to_string(ret_msg->rep->security));
return 1;
}
return 0;
}
/**
* Generate a request for DNS data.
*
* @param qstate: query state that is the parent.
* @param id: module id.
* @param name: what name to query for.
* @param namelen: length of name.
* @param qtype: query type.
* @param qclass: query class.
* @param flags: additional flags, such as the CD bit (BIT_CD), or 0.
* @return false on alloc failure.
*/
static int
generate_request(struct module_qstate* qstate, int id, uint8_t* name,
size_t namelen, uint16_t qtype, uint16_t qclass, uint16_t flags)
{
struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
struct module_qstate* newq;
struct query_info ask;
int valrec;
ask.qname = name;
ask.qname_len = namelen;
ask.qtype = qtype;
ask.qclass = qclass;
log_query_info(VERB_ALGO, "generate request", &ask);
fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
/* enable valrec flag to avoid recursion to the same validation
* routine, this lookup is simply a lookup. DLVs need validation */
if(qtype == LDNS_RR_TYPE_DLV)
valrec = 0;
else valrec = 1;
if(!(*qstate->env->attach_sub)(qstate, &ask,
(uint16_t)(BIT_RD|flags), 0, valrec, &newq)){
log_err("Could not generate request: out of memory");
return 0;
}
/* newq; validator does not need state created for that
* query, and its a 'normal' for iterator as well */
if(newq) {
/* add our blacklist to the query blacklist */
sock_list_merge(&newq->blacklist, newq->region,
vq->chain_blacklist);
}
qstate->ext_state[id] = module_wait_subquery;
return 1;
}
/**
* Prime trust anchor for use.
* Generate and dispatch a priming query for the given trust anchor.
* The trust anchor can be DNSKEY or DS and does not have to be signed.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param id: module id.
* @param toprime: what to prime.
* @return false on a processing error.
*/
static int
prime_trust_anchor(struct module_qstate* qstate, struct val_qstate* vq,
int id, struct trust_anchor* toprime)
{
int ret = generate_request(qstate, id, toprime->name, toprime->namelen,
LDNS_RR_TYPE_DNSKEY, toprime->dclass, BIT_CD);
if(!ret) {
log_err("Could not prime trust anchor: out of memory");
return 0;
}
/* ignore newq; validator does not need state created for that
* query, and its a 'normal' for iterator as well */
vq->wait_prime_ta = 1; /* to elicit PRIME_RESP_STATE processing
from the validator inform_super() routine */
/* store trust anchor name for later lookup when prime returns */
vq->trust_anchor_name = regional_alloc_init(qstate->region,
toprime->name, toprime->namelen);
vq->trust_anchor_len = toprime->namelen;
vq->trust_anchor_labs = toprime->namelabs;
if(!vq->trust_anchor_name) {
log_err("Could not prime trust anchor: out of memory");
return 0;
}
return 1;
}
/**
* Validate if the ANSWER and AUTHORITY sections contain valid rrsets.
* They must be validly signed with the given key.
* Tries to validate ADDITIONAL rrsets as well, but only to check them.
* Allows unsigned CNAME after a DNAME that expands the DNAME.
*
* Note that by the time this method is called, the process of finding the
* trusted DNSKEY rrset that signs this response must already have been
* completed.
*
* @param qstate: query state.
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to validate.
* @param key_entry: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
* @return false if any of the rrsets in the an or ns sections of the message
* fail to verify. The message is then set to bogus.
*/
static int
validate_msg_signatures(struct module_qstate* qstate, struct module_env* env,
struct val_env* ve, struct query_info* qchase,
struct reply_info* chase_reply, struct key_entry_key* key_entry)
{
uint8_t* sname;
size_t i, slen;
struct ub_packed_rrset_key* s;
enum sec_status sec;
int dname_seen = 0;
char* reason = NULL;
/* validate the ANSWER section */
for(i=0; i<chase_reply->an_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* Skip the CNAME following a (validated) DNAME.
* Because of the normalization routines in the iterator,
* there will always be an unsigned CNAME following a DNAME
* (unless qtype=DNAME). */
if(dname_seen && ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
dname_seen = 0;
/* CNAME was synthesized by our own iterator */
/* since the DNAME verified, mark the CNAME as secure */
((struct packed_rrset_data*)s->entry.data)->security =
sec_status_secure;
((struct packed_rrset_data*)s->entry.data)->trust =
rrset_trust_validated;
continue;
}
/* Verify the answer rrset */
sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason);
/* If the (answer) rrset failed to validate, then this
* message is BAD. */
if(sec != sec_status_secure) {
log_nametypeclass(VERB_QUERY, "validator: response "
"has failed ANSWER rrset:", s->rk.dname,
ntohs(s->rk.type), ntohs(s->rk.rrset_class));
errinf(qstate, reason);
if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME)
errinf(qstate, "for CNAME");
else if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME)
errinf(qstate, "for DNAME");
errinf_origin(qstate, qstate->reply_origin);
chase_reply->security = sec_status_bogus;
return 0;
}
/* Notice a DNAME that should be followed by an unsigned
* CNAME. */
if(qchase->qtype != LDNS_RR_TYPE_DNAME &&
ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME) {
dname_seen = 1;
}
}
/* validate the AUTHORITY section */
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
sec = val_verify_rrset_entry(env, ve, s, key_entry, &reason);
/* If anything in the authority section fails to be secure,
* we have a bad message. */
if(sec != sec_status_secure) {
log_nametypeclass(VERB_QUERY, "validator: response "
"has failed AUTHORITY rrset:", s->rk.dname,
ntohs(s->rk.type), ntohs(s->rk.rrset_class));
errinf(qstate, reason);
errinf_rrset(qstate, s);
errinf_origin(qstate, qstate->reply_origin);
chase_reply->security = sec_status_bogus;
return 0;
}
}
/* attempt to validate the ADDITIONAL section rrsets */
if(!ve->clean_additional)
return 1;
for(i=chase_reply->an_numrrsets+chase_reply->ns_numrrsets;
i<chase_reply->rrset_count; i++) {
s = chase_reply->rrsets[i];
/* only validate rrs that have signatures with the key */
/* leave others unchecked, those get removed later on too */
val_find_rrset_signer(s, &sname, &slen);
if(sname && query_dname_compare(sname, key_entry->name)==0)
(void)val_verify_rrset_entry(env, ve, s, key_entry,
&reason);
/* the additional section can fail to be secure,
* it is optional, check signature in case we need
* to clean the additional section later. */
}
return 1;
}
/**
* Detect wrong truncated response (say from BIND 9.6.1 that is forwarding
* and saw the NS record without signatures from a referral).
* The positive response has a mangled authority section.
* Remove that authority section and the additional section.
* @param rep: reply
* @return true if a wrongly truncated response.
*/
static int
detect_wrongly_truncated(struct reply_info* rep)
{
size_t i;
/* only NS in authority, and it is bogus */
if(rep->ns_numrrsets != 1 || rep->an_numrrsets == 0)
return 0;
if(ntohs(rep->rrsets[ rep->an_numrrsets ]->rk.type) != LDNS_RR_TYPE_NS)
return 0;
if(((struct packed_rrset_data*)rep->rrsets[ rep->an_numrrsets ]
->entry.data)->security == sec_status_secure)
return 0;
/* answer section is present and secure */
for(i=0; i<rep->an_numrrsets; i++) {
if(((struct packed_rrset_data*)rep->rrsets[ i ]
->entry.data)->security != sec_status_secure)
return 0;
}
verbose(VERB_ALGO, "truncating to minimal response");
return 1;
}
/**
* Given a "positive" response -- a response that contains an answer to the
* question, and no CNAME chain, validate this response.
*
* The answer and authority RRsets must already be verified as secure.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
*/
static void
validate_positive_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey)
{
uint8_t* wc = NULL;
int wc_NSEC_ok = 0;
int nsec3s_seen = 0;
size_t i;
struct ub_packed_rrset_key* s;
/* validate the ANSWER section - this will be the answer itself */
for(i=0; i<chase_reply->an_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* Check to see if the rrset is the result of a wildcard
* expansion. If so, an additional check will need to be
* made in the authority section. */
if(!val_rrset_wildcard(s, &wc)) {
log_nametypeclass(VERB_QUERY, "Positive response has "
"inconsistent wildcard sigs:", s->rk.dname,
ntohs(s->rk.type), ntohs(s->rk.rrset_class));
chase_reply->security = sec_status_bogus;
return;
}
}
/* validate the AUTHORITY section as well - this will generally be
* the NS rrset (which could be missing, no problem) */
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* If this is a positive wildcard response, and we have a
* (just verified) NSEC record, try to use it to 1) prove
* that qname doesn't exist and 2) that the correct wildcard
* was used. */
if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
wc_NSEC_ok = 1;
}
/* if not, continue looking for proof */
}
/* Otherwise, if this is a positive wildcard response and
* we have NSEC3 records */
if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
nsec3s_seen = 1;
}
}
/* If this was a positive wildcard response that we haven't already
* proven, and we have NSEC3 records, try to prove it using the NSEC3
* records. */
if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
enum sec_status sec = nsec3_prove_wildcard(env, ve,
chase_reply->rrsets+chase_reply->an_numrrsets,
chase_reply->ns_numrrsets, qchase, kkey, wc);
if(sec == sec_status_insecure) {
verbose(VERB_ALGO, "Positive wildcard response is "
"insecure");
chase_reply->security = sec_status_insecure;
return;
} else if(sec == sec_status_secure)
wc_NSEC_ok = 1;
}
/* If after all this, we still haven't proven the positive wildcard
* response, fail. */
if(wc != NULL && !wc_NSEC_ok) {
verbose(VERB_QUERY, "positive response was wildcard "
"expansion and did not prove original data "
"did not exist");
chase_reply->security = sec_status_bogus;
return;
}
verbose(VERB_ALGO, "Successfully validated positive response");
chase_reply->security = sec_status_secure;
}
/**
* Validate a NOERROR/NODATA signed response -- a response that has a
* NOERROR Rcode but no ANSWER section RRsets. This consists of making
* certain that the authority section NSEC/NSEC3s proves that the qname
* does exist and the qtype doesn't.
*
* The answer and authority RRsets must already be verified as secure.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
*/
static void
validate_nodata_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey)
{
/* Since we are here, there must be nothing in the ANSWER section to
* validate. */
/* (Note: CNAME/DNAME responses will not directly get here --
* instead, they are chased down into indiviual CNAME validations,
* and at the end of the cname chain a POSITIVE, or CNAME_NOANSWER
* validation.) */
/* validate the AUTHORITY section */
int has_valid_nsec = 0; /* If true, then the NODATA has been proven.*/
uint8_t* ce = NULL; /* for wildcard nodata responses. This is the
proven closest encloser. */
uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
int nsec3s_seen = 0; /* nsec3s seen */
struct ub_packed_rrset_key* s;
size_t i;
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* If we encounter an NSEC record, try to use it to prove
* NODATA.
* This needs to handle the ENT NODATA case. */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(nsec_proves_nodata(s, qchase, &wc)) {
has_valid_nsec = 1;
/* sets wc-encloser if wildcard applicable */
}
if(val_nsec_proves_name_error(s, qchase->qname)) {
ce = nsec_closest_encloser(qchase->qname, s);
}
if(val_nsec_proves_insecuredelegation(s, qchase)) {
verbose(VERB_ALGO, "delegation is insecure");
chase_reply->security = sec_status_insecure;
return;
}
} else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
nsec3s_seen = 1;
}
}
/* check to see if we have a wildcard NODATA proof. */
/* The wildcard NODATA is 1 NSEC proving that qname does not exist
* (and also proving what the closest encloser is), and 1 NSEC
* showing the matching wildcard, which must be *.closest_encloser. */
if(wc && !ce)
has_valid_nsec = 0;
else if(wc && ce) {
if(query_dname_compare(wc, ce) != 0) {
has_valid_nsec = 0;
}
}
if(!has_valid_nsec && nsec3s_seen) {
enum sec_status sec = nsec3_prove_nodata(env, ve,
chase_reply->rrsets+chase_reply->an_numrrsets,
chase_reply->ns_numrrsets, qchase, kkey);
if(sec == sec_status_insecure) {
verbose(VERB_ALGO, "NODATA response is insecure");
chase_reply->security = sec_status_insecure;
return;
} else if(sec == sec_status_secure)
has_valid_nsec = 1;
}
if(!has_valid_nsec) {
verbose(VERB_QUERY, "NODATA response failed to prove NODATA "
"status with NSEC/NSEC3");
if(verbosity >= VERB_ALGO)
log_dns_msg("Failed NODATA", qchase, chase_reply);
chase_reply->security = sec_status_bogus;
return;
}
verbose(VERB_ALGO, "successfully validated NODATA response.");
chase_reply->security = sec_status_secure;
}
/**
* Validate a NAMEERROR signed response -- a response that has a NXDOMAIN
* Rcode.
* This consists of making certain that the authority section NSEC proves
* that the qname doesn't exist and the covering wildcard also doesn't exist..
*
* The answer and authority RRsets must have already been verified as secure.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
* @param rcode: adjusted RCODE, in case of RCODE/proof mismatch leniency.
*/
static void
validate_nameerror_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey, int* rcode)
{
int has_valid_nsec = 0;
int has_valid_wnsec = 0;
int nsec3s_seen = 0;
struct ub_packed_rrset_key* s;
size_t i;
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(val_nsec_proves_name_error(s, qchase->qname))
has_valid_nsec = 1;
if(val_nsec_proves_no_wc(s, qchase->qname,
qchase->qname_len))
has_valid_wnsec = 1;
if(val_nsec_proves_insecuredelegation(s, qchase)) {
verbose(VERB_ALGO, "delegation is insecure");
chase_reply->security = sec_status_insecure;
return;
}
} else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3)
nsec3s_seen = 1;
}
if((!has_valid_nsec || !has_valid_wnsec) && nsec3s_seen) {
/* use NSEC3 proof, both answer and auth rrsets, in case
* NSEC3s end up in the answer (due to qtype=NSEC3 or so) */
chase_reply->security = nsec3_prove_nameerror(env, ve,
chase_reply->rrsets, chase_reply->an_numrrsets+
chase_reply->ns_numrrsets, qchase, kkey);
if(chase_reply->security != sec_status_secure) {
verbose(VERB_QUERY, "NameError response failed nsec, "
"nsec3 proof was %s", sec_status_to_string(
chase_reply->security));
return;
}
has_valid_nsec = 1;
has_valid_wnsec = 1;
}
/* If the message fails to prove either condition, it is bogus. */
if(!has_valid_nsec) {
verbose(VERB_QUERY, "NameError response has failed to prove: "
"qname does not exist");
chase_reply->security = sec_status_bogus;
/* Be lenient with RCODE in NSEC NameError responses */
validate_nodata_response(env, ve, qchase, chase_reply, kkey);
if (chase_reply->security == sec_status_secure)
*rcode = LDNS_RCODE_NOERROR;
return;
}
if(!has_valid_wnsec) {
verbose(VERB_QUERY, "NameError response has failed to prove: "
"covering wildcard does not exist");
chase_reply->security = sec_status_bogus;
/* Be lenient with RCODE in NSEC NameError responses */
validate_nodata_response(env, ve, qchase, chase_reply, kkey);
if (chase_reply->security == sec_status_secure)
*rcode = LDNS_RCODE_NOERROR;
return;
}
/* Otherwise, we consider the message secure. */
verbose(VERB_ALGO, "successfully validated NAME ERROR response.");
chase_reply->security = sec_status_secure;
}
/**
* Given a referral response, validate rrsets and take least trusted rrset
* as the current validation status.
*
* Note that by the time this method is called, the process of finding the
* trusted DNSKEY rrset that signs this response must already have been
* completed.
*
* @param chase_reply: answer to validate.
*/
static void
validate_referral_response(struct reply_info* chase_reply)
{
size_t i;
enum sec_status s;
/* message security equals lowest rrset security */
chase_reply->security = sec_status_secure;
for(i=0; i<chase_reply->rrset_count; i++) {
s = ((struct packed_rrset_data*)chase_reply->rrsets[i]
->entry.data)->security;
if(s < chase_reply->security)
chase_reply->security = s;
}
verbose(VERB_ALGO, "validated part of referral response as %s",
sec_status_to_string(chase_reply->security));
}
/**
* Given an "ANY" response -- a response that contains an answer to a
* qtype==ANY question, with answers. This does no checking that all
* types are present.
*
* NOTE: it may be possible to get parent-side delegation point records
* here, which won't all be signed. Right now, this routine relies on the
* upstream iterative resolver to not return these responses -- instead
* treating them as referrals.
*
* NOTE: RFC 4035 is silent on this issue, so this may change upon
* clarification. Clarification draft -05 says to not check all types are
* present.
*
* Note that by the time this method is called, the process of finding the
* trusted DNSKEY rrset that signs this response must already have been
* completed.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
*/
static void
validate_any_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey)
{
/* all answer and auth rrsets already verified */
/* but check if a wildcard response is given, then check NSEC/NSEC3
* for qname denial to see if wildcard is applicable */
uint8_t* wc = NULL;
int wc_NSEC_ok = 0;
int nsec3s_seen = 0;
size_t i;
struct ub_packed_rrset_key* s;
if(qchase->qtype != LDNS_RR_TYPE_ANY) {
log_err("internal error: ANY validation called for non-ANY");
chase_reply->security = sec_status_bogus;
return;
}
/* validate the ANSWER section - this will be the answer itself */
for(i=0; i<chase_reply->an_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* Check to see if the rrset is the result of a wildcard
* expansion. If so, an additional check will need to be
* made in the authority section. */
if(!val_rrset_wildcard(s, &wc)) {
log_nametypeclass(VERB_QUERY, "Positive ANY response"
" has inconsistent wildcard sigs:",
s->rk.dname, ntohs(s->rk.type),
ntohs(s->rk.rrset_class));
chase_reply->security = sec_status_bogus;
return;
}
}
/* if it was a wildcard, check for NSEC/NSEC3s in both answer
* and authority sections (NSEC may be moved to the ANSWER section) */
if(wc != NULL)
for(i=0; i<chase_reply->an_numrrsets+chase_reply->ns_numrrsets;
i++) {
s = chase_reply->rrsets[i];
/* If this is a positive wildcard response, and we have a
* (just verified) NSEC record, try to use it to 1) prove
* that qname doesn't exist and 2) that the correct wildcard
* was used. */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
wc_NSEC_ok = 1;
}
/* if not, continue looking for proof */
}
/* Otherwise, if this is a positive wildcard response and
* we have NSEC3 records */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
nsec3s_seen = 1;
}
}
/* If this was a positive wildcard response that we haven't already
* proven, and we have NSEC3 records, try to prove it using the NSEC3
* records. */
if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
/* look both in answer and auth section for NSEC3s */
enum sec_status sec = nsec3_prove_wildcard(env, ve,
chase_reply->rrsets,
chase_reply->an_numrrsets+chase_reply->ns_numrrsets,
qchase, kkey, wc);
if(sec == sec_status_insecure) {
verbose(VERB_ALGO, "Positive ANY wildcard response is "
"insecure");
chase_reply->security = sec_status_insecure;
return;
} else if(sec == sec_status_secure)
wc_NSEC_ok = 1;
}
/* If after all this, we still haven't proven the positive wildcard
* response, fail. */
if(wc != NULL && !wc_NSEC_ok) {
verbose(VERB_QUERY, "positive ANY response was wildcard "
"expansion and did not prove original data "
"did not exist");
chase_reply->security = sec_status_bogus;
return;
}
verbose(VERB_ALGO, "Successfully validated positive ANY response");
chase_reply->security = sec_status_secure;
}
/**
* Validate CNAME response, or DNAME+CNAME.
* This is just like a positive proof, except that this is about a
* DNAME+CNAME. Possible wildcard proof.
* Difference with positive proof is that this routine refuses
* wildcarded DNAMEs.
*
* The answer and authority rrsets must already be verified as secure.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
*/
static void
validate_cname_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey)
{
uint8_t* wc = NULL;
int wc_NSEC_ok = 0;
int nsec3s_seen = 0;
size_t i;
struct ub_packed_rrset_key* s;
/* validate the ANSWER section - this will be the CNAME (+DNAME) */
for(i=0; i<chase_reply->an_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* Check to see if the rrset is the result of a wildcard
* expansion. If so, an additional check will need to be
* made in the authority section. */
if(!val_rrset_wildcard(s, &wc)) {
log_nametypeclass(VERB_QUERY, "Cname response has "
"inconsistent wildcard sigs:", s->rk.dname,
ntohs(s->rk.type), ntohs(s->rk.rrset_class));
chase_reply->security = sec_status_bogus;
return;
}
/* Refuse wildcarded DNAMEs rfc 4597.
* Do not follow a wildcarded DNAME because
* its synthesized CNAME expansion is underdefined */
if(qchase->qtype != LDNS_RR_TYPE_DNAME &&
ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME && wc) {
log_nametypeclass(VERB_QUERY, "cannot validate a "
"wildcarded DNAME:", s->rk.dname,
ntohs(s->rk.type), ntohs(s->rk.rrset_class));
chase_reply->security = sec_status_bogus;
return;
}
/* If we have found a CNAME, stop looking for one.
* The iterator has placed the CNAME chain in correct
* order. */
if (ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
break;
}
}
/* AUTHORITY section */
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* If this is a positive wildcard response, and we have a
* (just verified) NSEC record, try to use it to 1) prove
* that qname doesn't exist and 2) that the correct wildcard
* was used. */
if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(val_nsec_proves_positive_wildcard(s, qchase, wc)) {
wc_NSEC_ok = 1;
}
/* if not, continue looking for proof */
}
/* Otherwise, if this is a positive wildcard response and
* we have NSEC3 records */
if(wc != NULL && ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
nsec3s_seen = 1;
}
}
/* If this was a positive wildcard response that we haven't already
* proven, and we have NSEC3 records, try to prove it using the NSEC3
* records. */
if(wc != NULL && !wc_NSEC_ok && nsec3s_seen) {
enum sec_status sec = nsec3_prove_wildcard(env, ve,
chase_reply->rrsets+chase_reply->an_numrrsets,
chase_reply->ns_numrrsets, qchase, kkey, wc);
if(sec == sec_status_insecure) {
verbose(VERB_ALGO, "wildcard CNAME response is "
"insecure");
chase_reply->security = sec_status_insecure;
return;
} else if(sec == sec_status_secure)
wc_NSEC_ok = 1;
}
/* If after all this, we still haven't proven the positive wildcard
* response, fail. */
if(wc != NULL && !wc_NSEC_ok) {
verbose(VERB_QUERY, "CNAME response was wildcard "
"expansion and did not prove original data "
"did not exist");
chase_reply->security = sec_status_bogus;
return;
}
verbose(VERB_ALGO, "Successfully validated CNAME response");
chase_reply->security = sec_status_secure;
}
/**
* Validate CNAME NOANSWER response, no more data after a CNAME chain.
* This can be a NODATA or a NAME ERROR case, but not both at the same time.
* We don't know because the rcode has been set to NOERROR by the CNAME.
*
* The answer and authority rrsets must already be verified as secure.
*
* @param env: module env for verify.
* @param ve: validator env for verify.
* @param qchase: query that was made.
* @param chase_reply: answer to that query to validate.
* @param kkey: the key entry, which is trusted, and which matches
* the signer of the answer. The key entry isgood().
*/
static void
validate_cname_noanswer_response(struct module_env* env, struct val_env* ve,
struct query_info* qchase, struct reply_info* chase_reply,
struct key_entry_key* kkey)
{
int nodata_valid_nsec = 0; /* If true, then NODATA has been proven.*/
uint8_t* ce = NULL; /* for wildcard nodata responses. This is the
proven closest encloser. */
uint8_t* wc = NULL; /* for wildcard nodata responses. wildcard nsec */
int nxdomain_valid_nsec = 0; /* if true, namerror has been proven */
int nxdomain_valid_wnsec = 0;
int nsec3s_seen = 0; /* nsec3s seen */
struct ub_packed_rrset_key* s;
size_t i;
/* the AUTHORITY section */
for(i=chase_reply->an_numrrsets; i<chase_reply->an_numrrsets+
chase_reply->ns_numrrsets; i++) {
s = chase_reply->rrsets[i];
/* If we encounter an NSEC record, try to use it to prove
* NODATA. This needs to handle the ENT NODATA case.
* Also try to prove NAMEERROR, and absence of a wildcard */
if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC) {
if(nsec_proves_nodata(s, qchase, &wc)) {
nodata_valid_nsec = 1;
/* set wc encloser if wildcard applicable */
}
if(val_nsec_proves_name_error(s, qchase->qname)) {
ce = nsec_closest_encloser(qchase->qname, s);
nxdomain_valid_nsec = 1;
}
if(val_nsec_proves_no_wc(s, qchase->qname,
qchase->qname_len))
nxdomain_valid_wnsec = 1;
if(val_nsec_proves_insecuredelegation(s, qchase)) {
verbose(VERB_ALGO, "delegation is insecure");
chase_reply->security = sec_status_insecure;
return;
}
} else if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
nsec3s_seen = 1;
}
}
/* check to see if we have a wildcard NODATA proof. */
/* The wildcard NODATA is 1 NSEC proving that qname does not exists
* (and also proving what the closest encloser is), and 1 NSEC
* showing the matching wildcard, which must be *.closest_encloser. */
if(wc && !ce)
nodata_valid_nsec = 0;
else if(wc && ce) {
if(query_dname_compare(wc, ce) != 0) {
nodata_valid_nsec = 0;
}
}
if(nxdomain_valid_nsec && !nxdomain_valid_wnsec) {
/* name error is missing wildcard denial proof */
nxdomain_valid_nsec = 0;
}
if(nodata_valid_nsec && nxdomain_valid_nsec) {
verbose(VERB_QUERY, "CNAMEchain to noanswer proves that name "
"exists and not exists, bogus");
chase_reply->security = sec_status_bogus;
return;
}
if(!nodata_valid_nsec && !nxdomain_valid_nsec && nsec3s_seen) {
int nodata;
enum sec_status sec = nsec3_prove_nxornodata(env, ve,
chase_reply->rrsets+chase_reply->an_numrrsets,
chase_reply->ns_numrrsets, qchase, kkey, &nodata);
if(sec == sec_status_insecure) {
verbose(VERB_ALGO, "CNAMEchain to noanswer response "
"is insecure");
chase_reply->security = sec_status_insecure;
return;
} else if(sec == sec_status_secure) {
if(nodata)
nodata_valid_nsec = 1;
else nxdomain_valid_nsec = 1;
}
}
if(!nodata_valid_nsec && !nxdomain_valid_nsec) {
verbose(VERB_QUERY, "CNAMEchain to noanswer response failed "
"to prove status with NSEC/NSEC3");
if(verbosity >= VERB_ALGO)
log_dns_msg("Failed CNAMEnoanswer", qchase, chase_reply);
chase_reply->security = sec_status_bogus;
return;
}
if(nodata_valid_nsec)
verbose(VERB_ALGO, "successfully validated CNAME chain to a "
"NODATA response.");
else verbose(VERB_ALGO, "successfully validated CNAME chain to a "
"NAMEERROR response.");
chase_reply->security = sec_status_secure;
}
/**
* Process init state for validator.
* Process the INIT state. First tier responses start in the INIT state.
* This is where they are vetted for validation suitability, and the initial
* key search is done.
*
* Currently, events the come through this routine will be either promoted
* to FINISHED/CNAME_RESP (no validation needed), FINDKEY (next step to
* validation), or will be (temporarily) retired and a new priming request
* event will be generated.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
* @return true if the event should be processed further on return, false if
* not.
*/
static int
processInit(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
uint8_t* lookup_name;
size_t lookup_len;
struct trust_anchor* anchor;
enum val_classification subtype = val_classify_response(
qstate->query_flags, &qstate->qinfo, &vq->qchase,
vq->orig_msg->rep, vq->rrset_skip);
if(vq->restart_count > VAL_MAX_RESTART_COUNT) {
verbose(VERB_ALGO, "restart count exceeded");
return val_error(qstate, id);
}
verbose(VERB_ALGO, "validator classification %s",
val_classification_to_string(subtype));
if(subtype == VAL_CLASS_REFERRAL &&
vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
/* referral uses the rrset name as qchase, to find keys for
* that rrset */
vq->qchase.qname = vq->orig_msg->rep->
rrsets[vq->rrset_skip]->rk.dname;
vq->qchase.qname_len = vq->orig_msg->rep->
rrsets[vq->rrset_skip]->rk.dname_len;
vq->qchase.qtype = ntohs(vq->orig_msg->rep->
rrsets[vq->rrset_skip]->rk.type);
vq->qchase.qclass = ntohs(vq->orig_msg->rep->
rrsets[vq->rrset_skip]->rk.rrset_class);
}
lookup_name = vq->qchase.qname;
lookup_len = vq->qchase.qname_len;
/* for type DS look at the parent side for keys/trustanchor */
/* also for NSEC not at apex */
if(vq->qchase.qtype == LDNS_RR_TYPE_DS ||
(vq->qchase.qtype == LDNS_RR_TYPE_NSEC &&
vq->orig_msg->rep->rrset_count > vq->rrset_skip &&
ntohs(vq->orig_msg->rep->rrsets[vq->rrset_skip]->rk.type) ==
LDNS_RR_TYPE_NSEC &&
!(vq->orig_msg->rep->rrsets[vq->rrset_skip]->
rk.flags&PACKED_RRSET_NSEC_AT_APEX))) {
dname_remove_label(&lookup_name, &lookup_len);
}
val_mark_indeterminate(vq->chase_reply, qstate->env->anchors,
qstate->env->rrset_cache, qstate->env);
vq->key_entry = NULL;
vq->empty_DS_name = NULL;
vq->ds_rrset = 0;
anchor = anchors_lookup(qstate->env->anchors,
lookup_name, lookup_len, vq->qchase.qclass);
/* Determine the signer/lookup name */
val_find_signer(subtype, &vq->qchase, vq->orig_msg->rep,
vq->rrset_skip, &vq->signer_name, &vq->signer_len);
if(vq->signer_name != NULL &&
!dname_subdomain_c(lookup_name, vq->signer_name)) {
log_nametypeclass(VERB_ALGO, "this signer name is not a parent "
"of lookupname, omitted", vq->signer_name, 0, 0);
vq->signer_name = NULL;
}
if(vq->signer_name == NULL) {
log_nametypeclass(VERB_ALGO, "no signer, using", lookup_name,
0, 0);
} else {
lookup_name = vq->signer_name;
lookup_len = vq->signer_len;
log_nametypeclass(VERB_ALGO, "signer is", lookup_name, 0, 0);
}
/* for NXDOMAIN it could be signed by a parent of the trust anchor */
if(subtype == VAL_CLASS_NAMEERROR && vq->signer_name &&
anchor && dname_strict_subdomain_c(anchor->name, lookup_name)){
lock_basic_unlock(&anchor->lock);
anchor = anchors_lookup(qstate->env->anchors,
lookup_name, lookup_len, vq->qchase.qclass);
if(!anchor) { /* unsigned parent denies anchor*/
verbose(VERB_QUERY, "unsigned parent zone denies"
" trust anchor, indeterminate");
vq->chase_reply->security = sec_status_indeterminate;
vq->state = VAL_FINISHED_STATE;
return 1;
}
verbose(VERB_ALGO, "trust anchor NXDOMAIN by signed parent");
} else if(subtype == VAL_CLASS_POSITIVE &&
qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
query_dname_compare(lookup_name, qstate->qinfo.qname) == 0) {
/* is a DNSKEY so lookup a bit higher since we want to
* get it from a parent or from trustanchor */
dname_remove_label(&lookup_name, &lookup_len);
}
if(vq->rrset_skip > 0 || subtype == VAL_CLASS_CNAME ||
subtype == VAL_CLASS_REFERRAL) {
/* extract this part of orig_msg into chase_reply for
* the eventual VALIDATE stage */
val_fill_reply(vq->chase_reply, vq->orig_msg->rep,
vq->rrset_skip, lookup_name, lookup_len,
vq->signer_name);
if(verbosity >= VERB_ALGO)
log_dns_msg("chased extract", &vq->qchase,
vq->chase_reply);
}
vq->key_entry = key_cache_obtain(ve->kcache, lookup_name, lookup_len,
vq->qchase.qclass, qstate->region, *qstate->env->now);
/* there is no key(from DLV) and no trust anchor */
if(vq->key_entry == NULL && anchor == NULL) {
/*response isn't under a trust anchor, so we cannot validate.*/
vq->chase_reply->security = sec_status_indeterminate;
/* go to finished state to cache this result */
vq->state = VAL_FINISHED_STATE;
return 1;
}
/* if not key, or if keyentry is *above* the trustanchor, i.e.
* the keyentry is based on another (higher) trustanchor */
else if(vq->key_entry == NULL || (anchor &&
dname_strict_subdomain_c(anchor->name, vq->key_entry->name))) {
/* trust anchor is an 'unsigned' trust anchor */
if(anchor && anchor->numDS == 0 && anchor->numDNSKEY == 0) {
vq->chase_reply->security = sec_status_insecure;
val_mark_insecure(vq->chase_reply, anchor->name,
qstate->env->rrset_cache, qstate->env);
lock_basic_unlock(&anchor->lock);
vq->dlv_checked=1; /* skip DLV check */
/* go to finished state to cache this result */
vq->state = VAL_FINISHED_STATE;
return 1;
}
/* fire off a trust anchor priming query. */
verbose(VERB_DETAIL, "prime trust anchor");
if(!prime_trust_anchor(qstate, vq, id, anchor)) {
lock_basic_unlock(&anchor->lock);
return val_error(qstate, id);
}
lock_basic_unlock(&anchor->lock);
/* and otherwise, don't continue processing this event.
* (it will be reactivated when the priming query returns). */
vq->state = VAL_FINDKEY_STATE;
return 0;
}
if(anchor) {
lock_basic_unlock(&anchor->lock);
}
if(key_entry_isnull(vq->key_entry)) {
/* response is under a null key, so we cannot validate
* However, we do set the status to INSECURE, since it is
* essentially proven insecure. */
vq->chase_reply->security = sec_status_insecure;
val_mark_insecure(vq->chase_reply, vq->key_entry->name,
qstate->env->rrset_cache, qstate->env);
/* go to finished state to cache this result */
vq->state = VAL_FINISHED_STATE;
return 1;
} else if(key_entry_isbad(vq->key_entry)) {
/* key is bad, chain is bad, reply is bogus */
errinf_dname(qstate, "key for validation", vq->key_entry->name);
errinf(qstate, "is marked as invalid");
if(key_entry_get_reason(vq->key_entry)) {
errinf(qstate, "because of a previous");
errinf(qstate, key_entry_get_reason(vq->key_entry));
}
/* no retries, stop bothering the authority until timeout */
vq->restart_count = VAL_MAX_RESTART_COUNT;
vq->chase_reply->security = sec_status_bogus;
vq->state = VAL_FINISHED_STATE;
return 1;
}
/* otherwise, we have our "closest" cached key -- continue
* processing in the next state. */
vq->state = VAL_FINDKEY_STATE;
return 1;
}
/**
* Process the FINDKEY state. Generally this just calculates the next name
* to query and either issues a DS or a DNSKEY query. It will check to see
* if the correct key has already been reached, in which case it will
* advance the event to the next state.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param id: module id.
* @return true if the event should be processed further on return, false if
* not.
*/
static int
processFindKey(struct module_qstate* qstate, struct val_qstate* vq, int id)
{
uint8_t* target_key_name, *current_key_name;
size_t target_key_len;
int strip_lab;
log_query_info(VERB_ALGO, "validator: FindKey", &vq->qchase);
/* We know that state.key_entry is not 0 or bad key -- if it were,
* then previous processing should have directed this event to
* a different state.
* It could be an isnull key, which signals that a DLV was just
* done and the DNSKEY after the DLV failed with dnssec-retry state
* and the DNSKEY has to be performed again. */
log_assert(vq->key_entry && !key_entry_isbad(vq->key_entry));
if(key_entry_isnull(vq->key_entry)) {
if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
vq->qchase.qclass, BIT_CD)) {
log_err("mem error generating DNSKEY request");
return val_error(qstate, id);
}
return 0;
}
target_key_name = vq->signer_name;
target_key_len = vq->signer_len;
if(!target_key_name) {
target_key_name = vq->qchase.qname;
target_key_len = vq->qchase.qname_len;
}
current_key_name = vq->key_entry->name;
/* If our current key entry matches our target, then we are done. */
if(query_dname_compare(target_key_name, current_key_name) == 0) {
vq->state = VAL_VALIDATE_STATE;
return 1;
}
if(vq->empty_DS_name) {
/* if the last empty nonterminal/emptyDS name we detected is
* below the current key, use that name to make progress
* along the chain of trust */
if(query_dname_compare(target_key_name,
vq->empty_DS_name) == 0) {
/* do not query for empty_DS_name again */
verbose(VERB_ALGO, "Cannot retrieve DS for signature");
errinf(qstate, "no signatures");
errinf_origin(qstate, qstate->reply_origin);
vq->chase_reply->security = sec_status_bogus;
vq->state = VAL_FINISHED_STATE;
return 1;
}
current_key_name = vq->empty_DS_name;
}
log_nametypeclass(VERB_ALGO, "current keyname", current_key_name,
LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
log_nametypeclass(VERB_ALGO, "target keyname", target_key_name,
LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
/* assert we are walking down the DNS tree */
if(!dname_subdomain_c(target_key_name, current_key_name)) {
verbose(VERB_ALGO, "bad signer name");
vq->chase_reply->security = sec_status_bogus;
vq->state = VAL_FINISHED_STATE;
return 1;
}
/* so this value is >= -1 */
strip_lab = dname_count_labels(target_key_name) -
dname_count_labels(current_key_name) - 1;
log_assert(strip_lab >= -1);
verbose(VERB_ALGO, "striplab %d", strip_lab);
if(strip_lab > 0) {
dname_remove_labels(&target_key_name, &target_key_len,
strip_lab);
}
log_nametypeclass(VERB_ALGO, "next keyname", target_key_name,
LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN);
/* The next step is either to query for the next DS, or to query
* for the next DNSKEY. */
if(vq->ds_rrset)
log_nametypeclass(VERB_ALGO, "DS RRset", vq->ds_rrset->rk.dname, LDNS_RR_TYPE_DS, LDNS_RR_CLASS_IN);
else verbose(VERB_ALGO, "No DS RRset");
if(vq->ds_rrset && query_dname_compare(vq->ds_rrset->rk.dname,
vq->key_entry->name) != 0) {
if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
vq->qchase.qclass, BIT_CD)) {
log_err("mem error generating DNSKEY request");
return val_error(qstate, id);
}
return 0;
}
if(!vq->ds_rrset || query_dname_compare(vq->ds_rrset->rk.dname,
target_key_name) != 0) {
/* check if there is a cache entry : pick up an NSEC if
* there is no DS, check if that NSEC has DS-bit unset, and
* thus can disprove the secure delagation we seek.
* We can then use that NSEC even in the absence of a SOA
* record that would be required by the iterator to supply
* a completely protocol-correct response.
* Uses negative cache for NSEC3 lookup of DS responses. */
/* only if cache not blacklisted, of course */
struct dns_msg* msg;
if(!qstate->blacklist && !vq->chain_blacklist &&
(msg=val_find_DS(qstate->env, target_key_name,
target_key_len, vq->qchase.qclass, qstate->region,
vq->key_entry->name)) ) {
verbose(VERB_ALGO, "Process cached DS response");
process_ds_response(qstate, vq, id, LDNS_RCODE_NOERROR,
msg, &msg->qinfo, NULL);
return 1; /* continue processing ds-response results */
}
if(!generate_request(qstate, id, target_key_name,
target_key_len, LDNS_RR_TYPE_DS, vq->qchase.qclass,
BIT_CD)) {
log_err("mem error generating DS request");
return val_error(qstate, id);
}
return 0;
}
/* Otherwise, it is time to query for the DNSKEY */
if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
vq->qchase.qclass, BIT_CD)) {
log_err("mem error generating DNSKEY request");
return val_error(qstate, id);
}
return 0;
}
/**
* Process the VALIDATE stage, the init and findkey stages are finished,
* and the right keys are available to validate the response.
* Or, there are no keys available, in order to invalidate the response.
*
* After validation, the status is recorded in the message and rrsets,
* and finished state is started.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
* @return true if the event should be processed further on return, false if
* not.
*/
static int
processValidate(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
enum val_classification subtype;
int rcode;
if(!vq->key_entry) {
verbose(VERB_ALGO, "validate: no key entry, failed");
return val_error(qstate, id);
}
/* This is the default next state. */
vq->state = VAL_FINISHED_STATE;
/* Unsigned responses must be underneath a "null" key entry.*/
if(key_entry_isnull(vq->key_entry)) {
verbose(VERB_DETAIL, "Verified that %sresponse is INSECURE",
vq->signer_name?"":"unsigned ");
vq->chase_reply->security = sec_status_insecure;
val_mark_insecure(vq->chase_reply, vq->key_entry->name,
qstate->env->rrset_cache, qstate->env);
key_cache_insert(ve->kcache, vq->key_entry, qstate);
return 1;
}
if(key_entry_isbad(vq->key_entry)) {
log_nametypeclass(VERB_DETAIL, "Could not establish a chain "
"of trust to keys for", vq->key_entry->name,
LDNS_RR_TYPE_DNSKEY, vq->key_entry->key_class);
vq->chase_reply->security = sec_status_bogus;
errinf(qstate, "while building chain of trust");
if(vq->restart_count >= VAL_MAX_RESTART_COUNT)
key_cache_insert(ve->kcache, vq->key_entry, qstate);
return 1;
}
/* signerName being null is the indicator that this response was
* unsigned */
if(vq->signer_name == NULL) {
log_query_info(VERB_ALGO, "processValidate: state has no "
"signer name", &vq->qchase);
verbose(VERB_DETAIL, "Could not establish validation of "
"INSECURE status of unsigned response.");
errinf(qstate, "no signatures");
errinf_origin(qstate, qstate->reply_origin);
vq->chase_reply->security = sec_status_bogus;
return 1;
}
subtype = val_classify_response(qstate->query_flags, &qstate->qinfo,
&vq->qchase, vq->orig_msg->rep, vq->rrset_skip);
/* check signatures in the message;
* answer and authority must be valid, additional is only checked. */
if(!validate_msg_signatures(qstate, qstate->env, ve, &vq->qchase,
vq->chase_reply, vq->key_entry)) {
/* workaround bad recursor out there that truncates (even
* with EDNS4k) to 512 by removing RRSIG from auth section
* for positive replies*/
if((subtype == VAL_CLASS_POSITIVE || subtype == VAL_CLASS_ANY
|| subtype == VAL_CLASS_CNAME) &&
detect_wrongly_truncated(vq->orig_msg->rep)) {
/* truncate the message some more */
vq->orig_msg->rep->ns_numrrsets = 0;
vq->orig_msg->rep->ar_numrrsets = 0;
vq->orig_msg->rep->rrset_count =
vq->orig_msg->rep->an_numrrsets;
vq->chase_reply->ns_numrrsets = 0;
vq->chase_reply->ar_numrrsets = 0;
vq->chase_reply->rrset_count =
vq->chase_reply->an_numrrsets;
qstate->errinf = NULL;
}
else {
verbose(VERB_DETAIL, "Validate: message contains "
"bad rrsets");
return 1;
}
}
switch(subtype) {
case VAL_CLASS_POSITIVE:
verbose(VERB_ALGO, "Validating a positive response");
validate_positive_response(qstate->env, ve,
&vq->qchase, vq->chase_reply, vq->key_entry);
verbose(VERB_DETAIL, "validate(positive): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
case VAL_CLASS_NODATA:
verbose(VERB_ALGO, "Validating a nodata response");
validate_nodata_response(qstate->env, ve,
&vq->qchase, vq->chase_reply, vq->key_entry);
verbose(VERB_DETAIL, "validate(nodata): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
case VAL_CLASS_NAMEERROR:
rcode = (int)FLAGS_GET_RCODE(vq->orig_msg->rep->flags);
verbose(VERB_ALGO, "Validating a nxdomain response");
validate_nameerror_response(qstate->env, ve,
&vq->qchase, vq->chase_reply, vq->key_entry, &rcode);
verbose(VERB_DETAIL, "validate(nxdomain): %s",
sec_status_to_string(
vq->chase_reply->security));
FLAGS_SET_RCODE(vq->orig_msg->rep->flags, rcode);
FLAGS_SET_RCODE(vq->chase_reply->flags, rcode);
break;
case VAL_CLASS_CNAME:
verbose(VERB_ALGO, "Validating a cname response");
validate_cname_response(qstate->env, ve,
&vq->qchase, vq->chase_reply, vq->key_entry);
verbose(VERB_DETAIL, "validate(cname): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
case VAL_CLASS_CNAMENOANSWER:
verbose(VERB_ALGO, "Validating a cname noanswer "
"response");
validate_cname_noanswer_response(qstate->env, ve,
&vq->qchase, vq->chase_reply, vq->key_entry);
verbose(VERB_DETAIL, "validate(cname_noanswer): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
case VAL_CLASS_REFERRAL:
verbose(VERB_ALGO, "Validating a referral response");
validate_referral_response(vq->chase_reply);
verbose(VERB_DETAIL, "validate(referral): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
case VAL_CLASS_ANY:
verbose(VERB_ALGO, "Validating a positive ANY "
"response");
validate_any_response(qstate->env, ve, &vq->qchase,
vq->chase_reply, vq->key_entry);
verbose(VERB_DETAIL, "validate(positive_any): %s",
sec_status_to_string(
vq->chase_reply->security));
break;
default:
log_err("validate: unhandled response subtype: %d",
subtype);
}
if(vq->chase_reply->security == sec_status_bogus) {
if(subtype == VAL_CLASS_POSITIVE)
errinf(qstate, "wildcard");
else errinf(qstate, val_classification_to_string(subtype));
errinf(qstate, "proof failed");
errinf_origin(qstate, qstate->reply_origin);
}
return 1;
}
/**
* Init DLV check.
* Called when a query is determined by other trust anchors to be insecure
* (or indeterminate). Then we look if there is a key in the DLV.
* Performs aggressive negative cache check to see if there is no key.
* Otherwise, spawns a DLV query, and changes to the DLV wait state.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
* @return true if there is no DLV.
* false: processing is finished for the validator operate().
* This function may exit in three ways:
* o no DLV (agressive cache), so insecure. (true)
* o error - stop processing (false)
* o DLV lookup was started, stop processing (false)
*/
static int
val_dlv_init(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
uint8_t* nm;
size_t nm_len;
/* there must be a DLV configured */
log_assert(qstate->env->anchors->dlv_anchor);
/* this bool is true to avoid looping in the DLV checks */
log_assert(vq->dlv_checked);
/* init the DLV lookup variables */
vq->dlv_lookup_name = NULL;
vq->dlv_lookup_name_len = 0;
vq->dlv_insecure_at = NULL;
vq->dlv_insecure_at_len = 0;
/* Determine the name for which we want to lookup DLV.
* This name is for the current message, or
* for the current RRset for CNAME, referral subtypes.
* If there is a signer, use that, otherwise the domain name */
if(vq->signer_name) {
nm = vq->signer_name;
nm_len = vq->signer_len;
} else {
/* use qchase */
nm = vq->qchase.qname;
nm_len = vq->qchase.qname_len;
if(vq->qchase.qtype == LDNS_RR_TYPE_DS)
dname_remove_label(&nm, &nm_len);
}
log_nametypeclass(VERB_ALGO, "DLV init look", nm, LDNS_RR_TYPE_DS,
vq->qchase.qclass);
log_assert(nm && nm_len);
/* sanity check: no DLV lookups below the DLV anchor itself.
* Like, an securely insecure delegation there makes no sense. */
if(dname_subdomain_c(nm, qstate->env->anchors->dlv_anchor->name)) {
verbose(VERB_ALGO, "DLV lookup within DLV repository denied");
return 1;
}
/* concat name (minus root label) + dlv name */
vq->dlv_lookup_name_len = nm_len - 1 +
qstate->env->anchors->dlv_anchor->namelen;
vq->dlv_lookup_name = regional_alloc(qstate->region,
vq->dlv_lookup_name_len);
if(!vq->dlv_lookup_name) {
log_err("Out of memory preparing DLV lookup");
return val_error(qstate, id);
}
memmove(vq->dlv_lookup_name, nm, nm_len-1);
memmove(vq->dlv_lookup_name+nm_len-1,
qstate->env->anchors->dlv_anchor->name,
qstate->env->anchors->dlv_anchor->namelen);
log_nametypeclass(VERB_ALGO, "DLV name", vq->dlv_lookup_name,
LDNS_RR_TYPE_DLV, vq->qchase.qclass);
/* determine where the insecure point was determined, the DLV must
* be equal or below that to continue building the trust chain
* down. May be NULL if no trust chain was built yet */
nm = NULL;
if(vq->key_entry && key_entry_isnull(vq->key_entry)) {
nm = vq->key_entry->name;
nm_len = vq->key_entry->namelen;
}
if(nm) {
vq->dlv_insecure_at_len = nm_len - 1 +
qstate->env->anchors->dlv_anchor->namelen;
vq->dlv_insecure_at = regional_alloc(qstate->region,
vq->dlv_insecure_at_len);
if(!vq->dlv_insecure_at) {
log_err("Out of memory preparing DLV lookup");
return val_error(qstate, id);
}
memmove(vq->dlv_insecure_at, nm, nm_len-1);
memmove(vq->dlv_insecure_at+nm_len-1,
qstate->env->anchors->dlv_anchor->name,
qstate->env->anchors->dlv_anchor->namelen);
log_nametypeclass(VERB_ALGO, "insecure_at",
vq->dlv_insecure_at, 0, vq->qchase.qclass);
}
/* If we can find the name in the aggressive negative cache,
* give up; insecure is the answer */
while(val_neg_dlvlookup(ve->neg_cache, vq->dlv_lookup_name,
vq->dlv_lookup_name_len, vq->qchase.qclass,
qstate->env->rrset_cache, *qstate->env->now)) {
/* go up */
dname_remove_label(&vq->dlv_lookup_name,
&vq->dlv_lookup_name_len);
/* too high? */
if(!dname_subdomain_c(vq->dlv_lookup_name,
qstate->env->anchors->dlv_anchor->name)) {
verbose(VERB_ALGO, "ask above dlv repo");
return 1; /* Above the repo is insecure */
}
/* above chain of trust? */
if(vq->dlv_insecure_at && !dname_subdomain_c(
vq->dlv_lookup_name, vq->dlv_insecure_at)) {
verbose(VERB_ALGO, "ask above insecure endpoint");
return 1;
}
}
/* perform a lookup for the DLV; with validation */
vq->state = VAL_DLVLOOKUP_STATE;
if(!generate_request(qstate, id, vq->dlv_lookup_name,
vq->dlv_lookup_name_len, LDNS_RR_TYPE_DLV,
vq->qchase.qclass, 0)) {
return val_error(qstate, id);
}
/* Find the closest encloser DLV from the repository.
* then that is used to build another chain of trust
* This may first require a query 'too low' that has NSECs in
* the answer, from which we determine the closest encloser DLV.
* When determine the closest encloser, skip empty nonterminals,
* since we want a nonempty node in the DLV repository. */
return 0;
}
/**
* The Finished state. The validation status (good or bad) has been determined.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
* @return true if the event should be processed further on return, false if
* not.
*/
static int
processFinished(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
enum val_classification subtype = val_classify_response(
qstate->query_flags, &qstate->qinfo, &vq->qchase,
vq->orig_msg->rep, vq->rrset_skip);
/* if the result is insecure or indeterminate and we have not
* checked the DLV yet, check the DLV */
if((vq->chase_reply->security == sec_status_insecure ||
vq->chase_reply->security == sec_status_indeterminate) &&
qstate->env->anchors->dlv_anchor && !vq->dlv_checked) {
vq->dlv_checked = 1;
if(!val_dlv_init(qstate, vq, ve, id))
return 0;
}
/* store overall validation result in orig_msg */
if(vq->rrset_skip == 0)
vq->orig_msg->rep->security = vq->chase_reply->security;
else if(subtype != VAL_CLASS_REFERRAL ||
vq->rrset_skip < vq->orig_msg->rep->an_numrrsets +
vq->orig_msg->rep->ns_numrrsets) {
/* ignore sec status of additional section if a referral
* type message skips there and
* use the lowest security status as end result. */
if(vq->chase_reply->security < vq->orig_msg->rep->security)
vq->orig_msg->rep->security =
vq->chase_reply->security;
}
if(subtype == VAL_CLASS_REFERRAL) {
/* for a referral, move to next unchecked rrset and check it*/
vq->rrset_skip = val_next_unchecked(vq->orig_msg->rep,
vq->rrset_skip);
if(vq->rrset_skip < vq->orig_msg->rep->rrset_count) {
/* and restart for this rrset */
verbose(VERB_ALGO, "validator: go to next rrset");
vq->chase_reply->security = sec_status_unchecked;
vq->dlv_checked = 0; /* can do DLV for this RR */
vq->state = VAL_INIT_STATE;
return 1;
}
/* referral chase is done */
}
if(vq->chase_reply->security != sec_status_bogus &&
subtype == VAL_CLASS_CNAME) {
/* chase the CNAME; process next part of the message */
if(!val_chase_cname(&vq->qchase, vq->orig_msg->rep,
&vq->rrset_skip)) {
verbose(VERB_ALGO, "validator: failed to chase CNAME");
vq->orig_msg->rep->security = sec_status_bogus;
} else {
/* restart process for new qchase at rrset_skip */
log_query_info(VERB_ALGO, "validator: chased to",
&vq->qchase);
vq->chase_reply->security = sec_status_unchecked;
vq->dlv_checked = 0; /* can do DLV for this RR */
vq->state = VAL_INIT_STATE;
return 1;
}
}
if(vq->orig_msg->rep->security == sec_status_secure) {
/* If the message is secure, check that all rrsets are
* secure (i.e. some inserted RRset for CNAME chain with
* a different signer name). And drop additional rrsets
* that are not secure (if clean-additional option is set) */
/* this may cause the msg to be marked bogus */
val_check_nonsecure(ve, vq->orig_msg->rep);
if(vq->orig_msg->rep->security == sec_status_secure) {
log_query_info(VERB_DETAIL, "validation success",
&qstate->qinfo);
}
}
/* if the result is bogus - set message ttl to bogus ttl to avoid
* endless bogus revalidation */
if(vq->orig_msg->rep->security == sec_status_bogus) {
/* see if we can try again to fetch data */
if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
int restart_count = vq->restart_count+1;
verbose(VERB_ALGO, "validation failed, "
"blacklist and retry to fetch data");
val_blacklist(&qstate->blacklist, qstate->region,
qstate->reply_origin, 0);
qstate->reply_origin = NULL;
qstate->errinf = NULL;
memset(vq, 0, sizeof(*vq));
vq->restart_count = restart_count;
vq->state = VAL_INIT_STATE;
verbose(VERB_ALGO, "pass back to next module");
qstate->ext_state[id] = module_restart_next;
return 0;
}
vq->orig_msg->rep->ttl = ve->bogus_ttl;
vq->orig_msg->rep->prefetch_ttl =
PREFETCH_TTL_CALC(vq->orig_msg->rep->ttl);
if(qstate->env->cfg->val_log_level >= 1 &&
!qstate->env->cfg->val_log_squelch) {
if(qstate->env->cfg->val_log_level < 2)
log_query_info(0, "validation failure",
&qstate->qinfo);
else {
char* err = errinf_to_str(qstate);
if(err) log_info("%s", err);
free(err);
}
}
/* If we are in permissive mode, bogus gets indeterminate */
if(ve->permissive_mode)
vq->orig_msg->rep->security = sec_status_indeterminate;
}
/* store results in cache */
if(qstate->query_flags&BIT_RD) {
/* if secure, this will override cache anyway, no need
* to check if from parentNS */
if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo,
vq->orig_msg->rep, 0, qstate->prefetch_leeway, 0, NULL,
qstate->query_flags)) {
log_err("out of memory caching validator results");
}
} else {
/* for a referral, store the verified RRsets */
/* and this does not get prefetched, so no leeway */
if(!dns_cache_store(qstate->env, &vq->orig_msg->qinfo,
vq->orig_msg->rep, 1, 0, 0, NULL,
qstate->query_flags)) {
log_err("out of memory caching validator results");
}
}
qstate->return_rcode = LDNS_RCODE_NOERROR;
qstate->return_msg = vq->orig_msg;
qstate->ext_state[id] = module_finished;
return 0;
}
/**
* The DLVLookup state. Process DLV lookups.
*
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
* @return true if the event should be processed further on return, false if
* not.
*/
static int
processDLVLookup(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
/* see if this we are ready to continue normal resolution */
/* we may need more DLV lookups */
if(vq->dlv_status==dlv_error)
verbose(VERB_ALGO, "DLV woke up with status dlv_error");
else if(vq->dlv_status==dlv_success)
verbose(VERB_ALGO, "DLV woke up with status dlv_success");
else if(vq->dlv_status==dlv_ask_higher)
verbose(VERB_ALGO, "DLV woke up with status dlv_ask_higher");
else if(vq->dlv_status==dlv_there_is_no_dlv)
verbose(VERB_ALGO, "DLV woke up with status dlv_there_is_no_dlv");
else verbose(VERB_ALGO, "DLV woke up with status unknown");
if(vq->dlv_status == dlv_error) {
verbose(VERB_QUERY, "failed DLV lookup");
return val_error(qstate, id);
} else if(vq->dlv_status == dlv_success) {
uint8_t* nm;
size_t nmlen;
/* chain continues with DNSKEY, continue in FINDKEY */
vq->state = VAL_FINDKEY_STATE;
/* strip off the DLV suffix from the name; could result in . */
log_assert(dname_subdomain_c(vq->ds_rrset->rk.dname,
qstate->env->anchors->dlv_anchor->name));
nmlen = vq->ds_rrset->rk.dname_len -
qstate->env->anchors->dlv_anchor->namelen + 1;
nm = regional_alloc_init(qstate->region,
vq->ds_rrset->rk.dname, nmlen);
if(!nm) {
log_err("Out of memory in DLVLook");
return val_error(qstate, id);
}
nm[nmlen-1] = 0;
vq->ds_rrset->rk.dname = nm;
vq->ds_rrset->rk.dname_len = nmlen;
/* create a nullentry for the key so the dnskey lookup
* can be retried after a validation failure for it */
vq->key_entry = key_entry_create_null(qstate->region,
nm, nmlen, vq->qchase.qclass, 0, 0);
if(!vq->key_entry) {
log_err("Out of memory in DLVLook");
return val_error(qstate, id);
}
if(!generate_request(qstate, id, vq->ds_rrset->rk.dname,
vq->ds_rrset->rk.dname_len, LDNS_RR_TYPE_DNSKEY,
vq->qchase.qclass, BIT_CD)) {
log_err("mem error generating DNSKEY request");
return val_error(qstate, id);
}
return 0;
} else if(vq->dlv_status == dlv_there_is_no_dlv) {
/* continue with the insecure result we got */
vq->state = VAL_FINISHED_STATE;
return 1;
}
log_assert(vq->dlv_status == dlv_ask_higher);
/* ask higher, make sure we stay in DLV repo, below dlv_at */
if(!dname_subdomain_c(vq->dlv_lookup_name,
qstate->env->anchors->dlv_anchor->name)) {
/* just like, there is no DLV */
verbose(VERB_ALGO, "ask above dlv repo");
vq->state = VAL_FINISHED_STATE;
return 1;
}
if(vq->dlv_insecure_at && !dname_subdomain_c(vq->dlv_lookup_name,
vq->dlv_insecure_at)) {
/* already checked a chain lower than dlv_lookup_name */
verbose(VERB_ALGO, "ask above insecure endpoint");
log_nametypeclass(VERB_ALGO, "enpt", vq->dlv_insecure_at, 0, 0);
vq->state = VAL_FINISHED_STATE;
return 1;
}
/* check negative cache before making new request */
if(val_neg_dlvlookup(ve->neg_cache, vq->dlv_lookup_name,
vq->dlv_lookup_name_len, vq->qchase.qclass,
qstate->env->rrset_cache, *qstate->env->now)) {
/* does not exist, go up one (go higher). */
dname_remove_label(&vq->dlv_lookup_name,
&vq->dlv_lookup_name_len);
/* limit number of labels, limited number of recursion */
return processDLVLookup(qstate, vq, ve, id);
}
if(!generate_request(qstate, id, vq->dlv_lookup_name,
vq->dlv_lookup_name_len, LDNS_RR_TYPE_DLV,
vq->qchase.qclass, 0)) {
return val_error(qstate, id);
}
return 0;
}
/**
* Handle validator state.
* If a method returns true, the next state is started. If false, then
* processing will stop.
* @param qstate: query state.
* @param vq: validator query state.
* @param ve: validator shared global environment.
* @param id: module id.
*/
static void
val_handle(struct module_qstate* qstate, struct val_qstate* vq,
struct val_env* ve, int id)
{
int cont = 1;
while(cont) {
verbose(VERB_ALGO, "val handle processing q with state %s",
val_state_to_string(vq->state));
switch(vq->state) {
case VAL_INIT_STATE:
cont = processInit(qstate, vq, ve, id);
break;
case VAL_FINDKEY_STATE:
cont = processFindKey(qstate, vq, id);
break;
case VAL_VALIDATE_STATE:
cont = processValidate(qstate, vq, ve, id);
break;
case VAL_FINISHED_STATE:
cont = processFinished(qstate, vq, ve, id);
break;
case VAL_DLVLOOKUP_STATE:
cont = processDLVLookup(qstate, vq, ve, id);
break;
default:
log_warn("validator: invalid state %d",
vq->state);
cont = 0;
break;
}
}
}
void
val_operate(struct module_qstate* qstate, enum module_ev event, int id,
struct outbound_entry* outbound)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
struct val_qstate* vq = (struct val_qstate*)qstate->minfo[id];
verbose(VERB_QUERY, "validator[module %d] operate: extstate:%s "
"event:%s", id, strextstate(qstate->ext_state[id]),
strmodulevent(event));
log_query_info(VERB_QUERY, "validator operate: query",
&qstate->qinfo);
if(vq && qstate->qinfo.qname != vq->qchase.qname)
log_query_info(VERB_QUERY, "validator operate: chased to",
&vq->qchase);
(void)outbound;
if(event == module_event_new ||
(event == module_event_pass && vq == NULL)) {
/* pass request to next module, to get it */
verbose(VERB_ALGO, "validator: pass to next module");
qstate->ext_state[id] = module_wait_module;
return;
}
if(event == module_event_moddone) {
/* check if validation is needed */
verbose(VERB_ALGO, "validator: nextmodule returned");
if(!needs_validation(qstate, qstate->return_rcode,
qstate->return_msg)) {
/* no need to validate this */
if(qstate->return_msg)
qstate->return_msg->rep->security =
sec_status_indeterminate;
qstate->ext_state[id] = module_finished;
return;
}
if(already_validated(qstate->return_msg)) {
qstate->ext_state[id] = module_finished;
return;
}
/* qclass ANY should have validation result from spawned
* queries. If we get here, it is bogus or an internal error */
if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
verbose(VERB_ALGO, "cannot validate classANY: bogus");
if(qstate->return_msg)
qstate->return_msg->rep->security =
sec_status_bogus;
qstate->ext_state[id] = module_finished;
return;
}
/* create state to start validation */
qstate->ext_state[id] = module_error; /* override this */
if(!vq) {
vq = val_new(qstate, id);
if(!vq) {
log_err("validator: malloc failure");
qstate->ext_state[id] = module_error;
return;
}
} else if(!vq->orig_msg) {
if(!val_new_getmsg(qstate, vq)) {
log_err("validator: malloc failure");
qstate->ext_state[id] = module_error;
return;
}
}
val_handle(qstate, vq, ve, id);
return;
}
if(event == module_event_pass) {
qstate->ext_state[id] = module_error; /* override this */
/* continue processing, since val_env exists */
val_handle(qstate, vq, ve, id);
return;
}
log_err("validator: bad event %s", strmodulevent(event));
qstate->ext_state[id] = module_error;
return;
}
/**
* Evaluate the response to a priming request.
*
* @param dnskey_rrset: DNSKEY rrset (can be NULL if none) in prime reply.
* (this rrset is allocated in the wrong region, not the qstate).
* @param ta: trust anchor.
* @param qstate: qstate that needs key.
* @param id: module id.
* @return new key entry or NULL on allocation failure.
* The key entry will either contain a validated DNSKEY rrset, or
* represent a Null key (query failed, but validation did not), or a
* Bad key (validation failed).
*/
static struct key_entry_key*
primeResponseToKE(struct ub_packed_rrset_key* dnskey_rrset,
struct trust_anchor* ta, struct module_qstate* qstate, int id)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
struct key_entry_key* kkey = NULL;
enum sec_status sec = sec_status_unchecked;
char* reason = NULL;
int downprot = 1;
if(!dnskey_rrset) {
log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
"could not fetch DNSKEY rrset",
ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
if(qstate->env->cfg->harden_dnssec_stripped) {
errinf(qstate, "no DNSKEY rrset");
kkey = key_entry_create_bad(qstate->region, ta->name,
ta->namelen, ta->dclass, BOGUS_KEY_TTL,
*qstate->env->now);
} else kkey = key_entry_create_null(qstate->region, ta->name,
ta->namelen, ta->dclass, NULL_KEY_TTL,
*qstate->env->now);
if(!kkey) {
log_err("out of memory: allocate fail prime key");
return NULL;
}
return kkey;
}
/* attempt to verify with trust anchor DS and DNSKEY */
kkey = val_verify_new_DNSKEYs_with_ta(qstate->region, qstate->env, ve,
dnskey_rrset, ta->ds_rrset, ta->dnskey_rrset, downprot,
&reason);
if(!kkey) {
log_err("out of memory: verifying prime TA");
return NULL;
}
if(key_entry_isgood(kkey))
sec = sec_status_secure;
else
sec = sec_status_bogus;
verbose(VERB_DETAIL, "validate keys with anchor(DS): %s",
sec_status_to_string(sec));
if(sec != sec_status_secure) {
log_nametypeclass(VERB_OPS, "failed to prime trust anchor -- "
"DNSKEY rrset is not secure",
ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
/* NOTE: in this case, we should probably reject the trust
* anchor for longer, perhaps forever. */
if(qstate->env->cfg->harden_dnssec_stripped) {
errinf(qstate, reason);
kkey = key_entry_create_bad(qstate->region, ta->name,
ta->namelen, ta->dclass, BOGUS_KEY_TTL,
*qstate->env->now);
} else kkey = key_entry_create_null(qstate->region, ta->name,
ta->namelen, ta->dclass, NULL_KEY_TTL,
*qstate->env->now);
if(!kkey) {
log_err("out of memory: allocate null prime key");
return NULL;
}
return kkey;
}
log_nametypeclass(VERB_DETAIL, "Successfully primed trust anchor",
ta->name, LDNS_RR_TYPE_DNSKEY, ta->dclass);
return kkey;
}
/**
* In inform supers, with the resulting message and rcode and the current
* keyset in the super state, validate the DS response, returning a KeyEntry.
*
* @param qstate: query state that is validating and asked for a DS.
* @param vq: validator query state
* @param id: module id.
* @param rcode: rcode result value.
* @param msg: result message (if rcode is OK).
* @param qinfo: from the sub query state, query info.
* @param ke: the key entry to return. It returns
* is_bad if the DS response fails to validate, is_null if the
* DS response indicated an end to secure space, is_good if the DS
* validated. It returns ke=NULL if the DS response indicated that the
* request wasn't a delegation point.
* @return 0 on servfail error (malloc failure).
*/
static int
ds_response_to_ke(struct module_qstate* qstate, struct val_qstate* vq,
int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
struct key_entry_key** ke)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
char* reason = NULL;
enum val_classification subtype;
if(rcode != LDNS_RCODE_NOERROR) {
char rc[16];
rc[0]=0;
(void)sldns_wire2str_rcode_buf(rcode, rc, sizeof(rc));
/* errors here pretty much break validation */
verbose(VERB_DETAIL, "DS response was error, thus bogus");
errinf(qstate, rc);
errinf(qstate, "no DS");
goto return_bogus;
}
subtype = val_classify_response(BIT_RD, qinfo, qinfo, msg->rep, 0);
if(subtype == VAL_CLASS_POSITIVE) {
struct ub_packed_rrset_key* ds;
enum sec_status sec;
ds = reply_find_answer_rrset(qinfo, msg->rep);
/* If there was no DS rrset, then we have mis-classified
* this message. */
if(!ds) {
log_warn("internal error: POSITIVE DS response was "
"missing DS.");
errinf(qstate, "no DS record");
goto return_bogus;
}
/* Verify only returns BOGUS or SECURE. If the rrset is
* bogus, then we are done. */
sec = val_verify_rrset_entry(qstate->env, ve, ds,
vq->key_entry, &reason);
if(sec != sec_status_secure) {
verbose(VERB_DETAIL, "DS rrset in DS response did "
"not verify");
errinf(qstate, reason);
goto return_bogus;
}
/* If the DS rrset validates, we still have to make sure
* that they are usable. */
if(!val_dsset_isusable(ds)) {
/* If they aren't usable, then we treat it like
* there was no DS. */
*ke = key_entry_create_null(qstate->region,
qinfo->qname, qinfo->qname_len, qinfo->qclass,
ub_packed_rrset_ttl(ds), *qstate->env->now);
return (*ke) != NULL;
}
/* Otherwise, we return the positive response. */
log_query_info(VERB_DETAIL, "validated DS", qinfo);
*ke = key_entry_create_rrset(qstate->region,
qinfo->qname, qinfo->qname_len, qinfo->qclass, ds,
NULL, *qstate->env->now);
return (*ke) != NULL;
} else if(subtype == VAL_CLASS_NODATA ||
subtype == VAL_CLASS_NAMEERROR) {
/* NODATA means that the qname exists, but that there was
* no DS. This is a pretty normal case. */
time_t proof_ttl = 0;
enum sec_status sec;
/* make sure there are NSECs or NSEC3s with signatures */
if(!val_has_signed_nsecs(msg->rep, &reason)) {
verbose(VERB_ALGO, "no NSECs: %s", reason);
errinf(qstate, reason);
goto return_bogus;
}
/* For subtype Name Error.
* attempt ANS 2.8.1.0 compatibility where it sets rcode
* to nxdomain, but really this is an Nodata/Noerror response.
* Find and prove the empty nonterminal in that case */
/* Try to prove absence of the DS with NSEC */
sec = val_nsec_prove_nodata_dsreply(
qstate->env, ve, qinfo, msg->rep, vq->key_entry,
&proof_ttl, &reason);
switch(sec) {
case sec_status_secure:
verbose(VERB_DETAIL, "NSEC RRset for the "
"referral proved no DS.");
*ke = key_entry_create_null(qstate->region,
qinfo->qname, qinfo->qname_len,
qinfo->qclass, proof_ttl,
*qstate->env->now);
return (*ke) != NULL;
case sec_status_insecure:
verbose(VERB_DETAIL, "NSEC RRset for the "
"referral proved not a delegation point");
*ke = NULL;
return 1;
case sec_status_bogus:
verbose(VERB_DETAIL, "NSEC RRset for the "
"referral did not prove no DS.");
errinf(qstate, reason);
goto return_bogus;
case sec_status_unchecked:
default:
/* NSEC proof did not work, try next */
break;
}
sec = nsec3_prove_nods(qstate->env, ve,
msg->rep->rrsets + msg->rep->an_numrrsets,
msg->rep->ns_numrrsets, qinfo, vq->key_entry, &reason);
switch(sec) {
case sec_status_insecure:
/* case insecure also continues to unsigned
* space. If nsec3-iter-count too high or
* optout, then treat below as unsigned */
case sec_status_secure:
verbose(VERB_DETAIL, "NSEC3s for the "
"referral proved no DS.");
*ke = key_entry_create_null(qstate->region,
qinfo->qname, qinfo->qname_len,
qinfo->qclass, proof_ttl,
*qstate->env->now);
return (*ke) != NULL;
case sec_status_indeterminate:
verbose(VERB_DETAIL, "NSEC3s for the "
"referral proved no delegation");
*ke = NULL;
return 1;
case sec_status_bogus:
verbose(VERB_DETAIL, "NSEC3s for the "
"referral did not prove no DS.");
errinf(qstate, reason);
goto return_bogus;
case sec_status_unchecked:
default:
/* NSEC3 proof did not work */
break;
}
/* Apparently, no available NSEC/NSEC3 proved NODATA, so
* this is BOGUS. */
verbose(VERB_DETAIL, "DS %s ran out of options, so return "
"bogus", val_classification_to_string(subtype));
errinf(qstate, "no DS but also no proof of that");
goto return_bogus;
} else if(subtype == VAL_CLASS_CNAME ||
subtype == VAL_CLASS_CNAMENOANSWER) {
/* if the CNAME matches the exact name we want and is signed
* properly, then also, we are sure that no DS exists there,
* much like a NODATA proof */
enum sec_status sec;
struct ub_packed_rrset_key* cname;
cname = reply_find_rrset_section_an(msg->rep, qinfo->qname,
qinfo->qname_len, LDNS_RR_TYPE_CNAME, qinfo->qclass);
if(!cname) {
errinf(qstate, "validator classified CNAME but no "
"CNAME of the queried name for DS");
goto return_bogus;
}
if(((struct packed_rrset_data*)cname->entry.data)->rrsig_count
== 0) {
if(msg->rep->an_numrrsets != 0 && ntohs(msg->rep->
rrsets[0]->rk.type)==LDNS_RR_TYPE_DNAME) {
errinf(qstate, "DS got DNAME answer");
} else {
errinf(qstate, "DS got unsigned CNAME answer");
}
goto return_bogus;
}
sec = val_verify_rrset_entry(qstate->env, ve, cname,
vq->key_entry, &reason);
if(sec == sec_status_secure) {
verbose(VERB_ALGO, "CNAME validated, "
"proof that DS does not exist");
/* and that it is not a referral point */
*ke = NULL;
return 1;
}
errinf(qstate, "CNAME in DS response was not secure.");
errinf(qstate, reason);
goto return_bogus;
} else {
verbose(VERB_QUERY, "Encountered an unhandled type of "
"DS response, thus bogus.");
errinf(qstate, "no DS and");
if(FLAGS_GET_RCODE(msg->rep->flags) != LDNS_RCODE_NOERROR) {
char rc[16];
rc[0]=0;
(void)sldns_wire2str_rcode_buf((int)FLAGS_GET_RCODE(
msg->rep->flags), rc, sizeof(rc));
errinf(qstate, rc);
} else errinf(qstate, val_classification_to_string(subtype));
errinf(qstate, "message fails to prove that");
goto return_bogus;
}
return_bogus:
*ke = key_entry_create_bad(qstate->region, qinfo->qname,
qinfo->qname_len, qinfo->qclass,
BOGUS_KEY_TTL, *qstate->env->now);
return (*ke) != NULL;
}
/**
* Process DS response. Called from inform_supers.
* Because it is in inform_supers, the mesh itself is busy doing callbacks
* for a state that is to be deleted soon; don't touch the mesh; instead
* set a state in the super, as the super will be reactivated soon.
* Perform processing to determine what state to set in the super.
*
* @param qstate: query state that is validating and asked for a DS.
* @param vq: validator query state
* @param id: module id.
* @param rcode: rcode result value.
* @param msg: result message (if rcode is OK).
* @param qinfo: from the sub query state, query info.
* @param origin: the origin of msg.
*/
static void
process_ds_response(struct module_qstate* qstate, struct val_qstate* vq,
int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
struct sock_list* origin)
{
struct key_entry_key* dske = NULL;
uint8_t* olds = vq->empty_DS_name;
vq->empty_DS_name = NULL;
if(!ds_response_to_ke(qstate, vq, id, rcode, msg, qinfo, &dske)) {
log_err("malloc failure in process_ds_response");
vq->key_entry = NULL; /* make it error */
vq->state = VAL_VALIDATE_STATE;
return;
}
if(dske == NULL) {
vq->empty_DS_name = regional_alloc_init(qstate->region,
qinfo->qname, qinfo->qname_len);
if(!vq->empty_DS_name) {
log_err("malloc failure in empty_DS_name");
vq->key_entry = NULL; /* make it error */
vq->state = VAL_VALIDATE_STATE;
return;
}
vq->empty_DS_len = qinfo->qname_len;
vq->chain_blacklist = NULL;
/* ds response indicated that we aren't on a delegation point.
* Keep the forState.state on FINDKEY. */
} else if(key_entry_isgood(dske)) {
vq->ds_rrset = key_entry_get_rrset(dske, qstate->region);
if(!vq->ds_rrset) {
log_err("malloc failure in process DS");
vq->key_entry = NULL; /* make it error */
vq->state = VAL_VALIDATE_STATE;
return;
}
vq->chain_blacklist = NULL; /* fresh blacklist for next part*/
/* Keep the forState.state on FINDKEY. */
} else if(key_entry_isbad(dske)
&& vq->restart_count < VAL_MAX_RESTART_COUNT) {
vq->empty_DS_name = olds;
val_blacklist(&vq->chain_blacklist, qstate->region, origin, 1);
qstate->errinf = NULL;
vq->restart_count++;
} else {
if(key_entry_isbad(dske)) {
errinf_origin(qstate, origin);
errinf_dname(qstate, "for DS", qinfo->qname);
}
/* NOTE: the reason for the DS to be not good (that is,
* either bad or null) should have been logged by
* dsResponseToKE. */
vq->key_entry = dske;
/* The FINDKEY phase has ended, so move on. */
vq->state = VAL_VALIDATE_STATE;
}
}
/**
* Process DNSKEY response. Called from inform_supers.
* Sets the key entry in the state.
* Because it is in inform_supers, the mesh itself is busy doing callbacks
* for a state that is to be deleted soon; don't touch the mesh; instead
* set a state in the super, as the super will be reactivated soon.
* Perform processing to determine what state to set in the super.
*
* @param qstate: query state that is validating and asked for a DNSKEY.
* @param vq: validator query state
* @param id: module id.
* @param rcode: rcode result value.
* @param msg: result message (if rcode is OK).
* @param qinfo: from the sub query state, query info.
* @param origin: the origin of msg.
*/
static void
process_dnskey_response(struct module_qstate* qstate, struct val_qstate* vq,
int id, int rcode, struct dns_msg* msg, struct query_info* qinfo,
struct sock_list* origin)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
struct key_entry_key* old = vq->key_entry;
struct ub_packed_rrset_key* dnskey = NULL;
int downprot;
char* reason = NULL;
if(rcode == LDNS_RCODE_NOERROR)
dnskey = reply_find_answer_rrset(qinfo, msg->rep);
if(dnskey == NULL) {
/* bad response */
verbose(VERB_DETAIL, "Missing DNSKEY RRset in response to "
"DNSKEY query.");
if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
val_blacklist(&vq->chain_blacklist, qstate->region,
origin, 1);
qstate->errinf = NULL;
vq->restart_count++;
return;
}
vq->key_entry = key_entry_create_bad(qstate->region,
qinfo->qname, qinfo->qname_len, qinfo->qclass,
BOGUS_KEY_TTL, *qstate->env->now);
if(!vq->key_entry) {
log_err("alloc failure in missing dnskey response");
/* key_entry is NULL for failure in Validate */
}
errinf(qstate, "No DNSKEY record");
errinf_origin(qstate, origin);
errinf_dname(qstate, "for key", qinfo->qname);
vq->state = VAL_VALIDATE_STATE;
return;
}
if(!vq->ds_rrset) {
log_err("internal error: no DS rrset for new DNSKEY response");
vq->key_entry = NULL;
vq->state = VAL_VALIDATE_STATE;
return;
}
downprot = 1;
vq->key_entry = val_verify_new_DNSKEYs(qstate->region, qstate->env,
ve, dnskey, vq->ds_rrset, downprot, &reason);
if(!vq->key_entry) {
log_err("out of memory in verify new DNSKEYs");
vq->state = VAL_VALIDATE_STATE;
return;
}
/* If the key entry isBad or isNull, then we can move on to the next
* state. */
if(!key_entry_isgood(vq->key_entry)) {
if(key_entry_isbad(vq->key_entry)) {
if(vq->restart_count < VAL_MAX_RESTART_COUNT) {
val_blacklist(&vq->chain_blacklist,
qstate->region, origin, 1);
qstate->errinf = NULL;
vq->restart_count++;
vq->key_entry = old;
return;
}
verbose(VERB_DETAIL, "Did not match a DS to a DNSKEY, "
"thus bogus.");
errinf(qstate, reason);
errinf_origin(qstate, origin);
errinf_dname(qstate, "for key", qinfo->qname);
}
vq->chain_blacklist = NULL;
vq->state = VAL_VALIDATE_STATE;
return;
}
vq->chain_blacklist = NULL;
qstate->errinf = NULL;
/* The DNSKEY validated, so cache it as a trusted key rrset. */
key_cache_insert(ve->kcache, vq->key_entry, qstate);
/* If good, we stay in the FINDKEY state. */
log_query_info(VERB_DETAIL, "validated DNSKEY", qinfo);
}
/**
* Process prime response
* Sets the key entry in the state.
*
* @param qstate: query state that is validating and primed a trust anchor.
* @param vq: validator query state
* @param id: module id.
* @param rcode: rcode result value.
* @param msg: result message (if rcode is OK).
* @param origin: the origin of msg.
*/
static void
process_prime_response(struct module_qstate* qstate, struct val_qstate* vq,
int id, int rcode, struct dns_msg* msg, struct sock_list* origin)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
struct ub_packed_rrset_key* dnskey_rrset = NULL;
struct trust_anchor* ta = anchor_find(qstate->env->anchors,
vq->trust_anchor_name, vq->trust_anchor_labs,
vq->trust_anchor_len, vq->qchase.qclass);
if(!ta) {
/* trust anchor revoked, restart with less anchors */
vq->state = VAL_INIT_STATE;
if(!vq->trust_anchor_name)
vq->state = VAL_VALIDATE_STATE; /* break a loop */
vq->trust_anchor_name = NULL;
return;
}
/* Fetch and validate the keyEntry that corresponds to the
* current trust anchor. */
if(rcode == LDNS_RCODE_NOERROR) {
dnskey_rrset = reply_find_rrset_section_an(msg->rep,
ta->name, ta->namelen, LDNS_RR_TYPE_DNSKEY,
ta->dclass);
}
if(ta->autr) {
if(!autr_process_prime(qstate->env, ve, ta, dnskey_rrset)) {
/* trust anchor revoked, restart with less anchors */
vq->state = VAL_INIT_STATE;
vq->trust_anchor_name = NULL;
return;
}
}
vq->key_entry = primeResponseToKE(dnskey_rrset, ta, qstate, id);
lock_basic_unlock(&ta->lock);
if(vq->key_entry) {
if(key_entry_isbad(vq->key_entry)
&& vq->restart_count < VAL_MAX_RESTART_COUNT) {
val_blacklist(&vq->chain_blacklist, qstate->region,
origin, 1);
qstate->errinf = NULL;
vq->restart_count++;
vq->key_entry = NULL;
vq->state = VAL_INIT_STATE;
return;
}
vq->chain_blacklist = NULL;
errinf_origin(qstate, origin);
errinf_dname(qstate, "for trust anchor", ta->name);
/* store the freshly primed entry in the cache */
key_cache_insert(ve->kcache, vq->key_entry, qstate);
}
/* If the result of the prime is a null key, skip the FINDKEY state.*/
if(!vq->key_entry || key_entry_isnull(vq->key_entry) ||
key_entry_isbad(vq->key_entry)) {
vq->state = VAL_VALIDATE_STATE;
}
/* the qstate will be reactivated after inform_super is done */
}
/**
* Process DLV response. Called from inform_supers.
* Because it is in inform_supers, the mesh itself is busy doing callbacks
* for a state that is to be deleted soon; don't touch the mesh; instead
* set a state in the super, as the super will be reactivated soon.
* Perform processing to determine what state to set in the super.
*
* @param qstate: query state that is validating and asked for a DLV.
* @param vq: validator query state
* @param id: module id.
* @param rcode: rcode result value.
* @param msg: result message (if rcode is OK).
* @param qinfo: from the sub query state, query info.
*/
static void
process_dlv_response(struct module_qstate* qstate, struct val_qstate* vq,
int id, int rcode, struct dns_msg* msg, struct query_info* qinfo)
{
struct val_env* ve = (struct val_env*)qstate->env->modinfo[id];
verbose(VERB_ALGO, "process dlv response to super");
if(rcode != LDNS_RCODE_NOERROR) {
/* lookup failed, set in vq to give up */
vq->dlv_status = dlv_error;
verbose(VERB_ALGO, "response is error");
return;
}
if(msg->rep->security != sec_status_secure) {
vq->dlv_status = dlv_error;
verbose(VERB_ALGO, "response is not secure, %s",
sec_status_to_string(msg->rep->security));
return;
}
/* was the lookup a success? validated DLV? */
if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_NOERROR &&
msg->rep->an_numrrsets == 1 &&
msg->rep->security == sec_status_secure &&
ntohs(msg->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DLV &&
ntohs(msg->rep->rrsets[0]->rk.rrset_class) == qinfo->qclass &&
query_dname_compare(msg->rep->rrsets[0]->rk.dname,
vq->dlv_lookup_name) == 0) {
/* yay! it is just like a DS */
vq->ds_rrset = (struct ub_packed_rrset_key*)
regional_alloc_init(qstate->region,
msg->rep->rrsets[0], sizeof(*vq->ds_rrset));
if(!vq->ds_rrset) {
log_err("out of memory in process_dlv");
return;
}
vq->ds_rrset->entry.key = vq->ds_rrset;
vq->ds_rrset->rk.dname = (uint8_t*)regional_alloc_init(
qstate->region, vq->ds_rrset->rk.dname,
vq->ds_rrset->rk.dname_len);
if(!vq->ds_rrset->rk.dname) {
log_err("out of memory in process_dlv");
vq->dlv_status = dlv_error;
return;
}
vq->ds_rrset->entry.data = regional_alloc_init(qstate->region,
vq->ds_rrset->entry.data,
packed_rrset_sizeof(vq->ds_rrset->entry.data));
if(!vq->ds_rrset->entry.data) {
log_err("out of memory in process_dlv");
vq->dlv_status = dlv_error;
return;
}
packed_rrset_ptr_fixup(vq->ds_rrset->entry.data);
/* make vq do a DNSKEY query next up */
vq->dlv_status = dlv_success;
return;
}
/* store NSECs into negative cache */
val_neg_addreply(ve->neg_cache, msg->rep);
/* was the lookup a failure?
* if we have to go up into the DLV for a higher DLV anchor
* then set this in the vq, so it can make queries when activated.
* See if the NSECs indicate that we should look for higher DLV
* or, that there is no DLV securely */
if(!val_nsec_check_dlv(qinfo, msg->rep, &vq->dlv_lookup_name,
&vq->dlv_lookup_name_len)) {
vq->dlv_status = dlv_error;
verbose(VERB_ALGO, "nsec error");
return;
}
if(!dname_subdomain_c(vq->dlv_lookup_name,
qstate->env->anchors->dlv_anchor->name)) {
vq->dlv_status = dlv_there_is_no_dlv;
return;
}
vq->dlv_status = dlv_ask_higher;
}
/*
* inform validator super.
*
* @param qstate: query state that finished.
* @param id: module id.
* @param super: the qstate to inform.
*/
void
val_inform_super(struct module_qstate* qstate, int id,
struct module_qstate* super)
{
struct val_qstate* vq = (struct val_qstate*)super->minfo[id];
log_query_info(VERB_ALGO, "validator: inform_super, sub is",
&qstate->qinfo);
log_query_info(VERB_ALGO, "super is", &super->qinfo);
if(!vq) {
verbose(VERB_ALGO, "super: has no validator state");
return;
}
if(vq->wait_prime_ta) {
vq->wait_prime_ta = 0;
process_prime_response(super, vq, id, qstate->return_rcode,
qstate->return_msg, qstate->reply_origin);
return;
}
if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS) {
process_ds_response(super, vq, id, qstate->return_rcode,
qstate->return_msg, &qstate->qinfo,
qstate->reply_origin);
return;
} else if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY) {
process_dnskey_response(super, vq, id, qstate->return_rcode,
qstate->return_msg, &qstate->qinfo,
qstate->reply_origin);
return;
} else if(qstate->qinfo.qtype == LDNS_RR_TYPE_DLV) {
process_dlv_response(super, vq, id, qstate->return_rcode,
qstate->return_msg, &qstate->qinfo);
return;
}
log_err("internal error in validator: no inform_supers possible");
}
void
val_clear(struct module_qstate* qstate, int id)
{
if(!qstate)
return;
/* everything is allocated in the region, so assign NULL */
qstate->minfo[id] = NULL;
}
size_t
val_get_mem(struct module_env* env, int id)
{
struct val_env* ve = (struct val_env*)env->modinfo[id];
if(!ve)
return 0;
return sizeof(*ve) + key_cache_get_mem(ve->kcache) +
val_neg_get_mem(ve->neg_cache) +
sizeof(size_t)*2*ve->nsec3_keyiter_count;
}
/**
* The validator function block
*/
static struct module_func_block val_block = {
"validator",
&val_init, &val_deinit, &val_operate, &val_inform_super, &val_clear,
&val_get_mem
};
struct module_func_block*
val_get_funcblock(void)
{
return &val_block;
}
const char*
val_state_to_string(enum val_state state)
{
switch(state) {
case VAL_INIT_STATE: return "VAL_INIT_STATE";
case VAL_FINDKEY_STATE: return "VAL_FINDKEY_STATE";
case VAL_VALIDATE_STATE: return "VAL_VALIDATE_STATE";
case VAL_FINISHED_STATE: return "VAL_FINISHED_STATE";
case VAL_DLVLOOKUP_STATE: return "VAL_DLVLOOKUP_STATE";
}
return "UNKNOWN VALIDATOR STATE";
}
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