validator.c

非常好的dns解析软件

			return (ISC_R_SUCCESS);
		}

		do {
			result = verify(val, val->key, &rdata,
					val->siginfo->keyid);
			if (result == ISC_R_SUCCESS)
				break;
			if (val->keynode != NULL) {
				dns_keynode_t *nextnode = NULL;
				result = dns_keytable_findnextkeynode(
							val->keytable,
							val->keynode,
							&nextnode);
				dns_keytable_detachkeynode(val->keytable,
							   &val->keynode);
				val->keynode = nextnode;
				if (result != ISC_R_SUCCESS) {
					val->key = NULL;
					break;
				}
				val->key = dns_keynode_key(val->keynode);
			} else {
				if (get_dst_key(val, val->siginfo, val->keyset)
				    != ISC_R_SUCCESS)
					break;
			}
		} while (1);
		if (result != ISC_R_SUCCESS)
			validator_log(val, ISC_LOG_DEBUG(3),
				      "failed to verify rdataset");
		else {
			isc_uint32_t ttl;
			isc_stdtime_t now;

			isc_stdtime_get(&now);
			ttl = ISC_MIN(event->rdataset->ttl,
				      val->siginfo->timeexpire - now);
			if (val->keyset != NULL)
				ttl = ISC_MIN(ttl, val->keyset->ttl);
			event->rdataset->ttl = ttl;
			event->sigrdataset->ttl = ttl;
		}

		if (val->keynode != NULL)
			dns_keytable_detachkeynode(val->keytable,
						   &val->keynode);
		else {
			if (val->key != NULL)
				dst_key_free(&val->key);
			if (val->keyset != NULL) {
				dns_rdataset_disassociate(val->keyset);
				val->keyset = NULL;
			}
		}
		val->key = NULL;
		if ((val->attributes & VALATTR_NEEDNOQNAME) != 0) {
			if (val->event->message == NULL) {
				validator_log(val, ISC_LOG_DEBUG(3),
				      "no message available for noqname proof");
				return (DNS_R_NOVALIDSIG);
			}
			validator_log(val, ISC_LOG_DEBUG(3),
				      "looking for noqname proof");
			return (nsecvalidate(val, ISC_FALSE));
		} else if (result == ISC_R_SUCCESS) {
			event->rdataset->trust = dns_trust_secure;
			event->sigrdataset->trust = dns_trust_secure;
			validator_log(val, ISC_LOG_DEBUG(3),
				      "marking as secure");
			return (result);
		} else {
			validator_log(val, ISC_LOG_DEBUG(3),
				      "verify failure: %s",
				      isc_result_totext(result));
			resume = ISC_FALSE;
		}
	}
	if (result != ISC_R_NOMORE) {
		validator_log(val, ISC_LOG_DEBUG(3),
			      "failed to iterate signatures: %s",
			      isc_result_totext(result));
		return (result);
	}

	validator_log(val, ISC_LOG_INFO, "no valid signature found");
	return (DNS_R_NOVALIDSIG);
}

/*%
 * Validate the DNSKEY RRset by looking for a DNSKEY that matches a
 * DLV record and that also verifies the DNSKEY RRset.
 */
static isc_result_t
dlv_validatezonekey(dns_validator_t *val) {
	dns_keytag_t keytag;
	dns_rdata_dlv_t dlv;
	dns_rdata_dnskey_t key;
	dns_rdata_rrsig_t sig;
	dns_rdata_t dlvrdata = DNS_RDATA_INIT;
	dns_rdata_t keyrdata = DNS_RDATA_INIT;
	dns_rdata_t newdsrdata = DNS_RDATA_INIT;
	dns_rdata_t sigrdata = DNS_RDATA_INIT;
	dns_rdataset_t trdataset;
	dst_key_t *dstkey;
	isc_boolean_t supported_algorithm;
	isc_result_t result;
	unsigned char dsbuf[DNS_DS_BUFFERSIZE];
	isc_uint8_t digest_type;

	validator_log(val, ISC_LOG_DEBUG(3), "dlv_validatezonekey");

	/*
	 * Look through the DLV record and find the keys that can sign the
	 * key set and the matching signature.  For each such key, attempt
	 * verification.
	 */
	supported_algorithm = ISC_FALSE;

	/*
	 * If DNS_DSDIGEST_SHA256 is present we are required to prefer
	 * it over DNS_DSDIGEST_SHA1.  This in practice means that we
	 * need to ignore DNS_DSDIGEST_SHA1 if a DNS_DSDIGEST_SHA256
	 * is present.
	 */
	digest_type = DNS_DSDIGEST_SHA1;
	for (result = dns_rdataset_first(&val->dlv);
	     result == ISC_R_SUCCESS;
	     result = dns_rdataset_next(&val->dlv)) {
		dns_rdata_reset(&dlvrdata);
		dns_rdataset_current(&val->dlv, &dlvrdata);
		dns_rdata_tostruct(&dlvrdata, &dlv, NULL);

		if (!dns_resolver_algorithm_supported(val->view->resolver,
						      val->event->name,
						      dlv.algorithm))
			continue;

		if (dlv.digest_type == DNS_DSDIGEST_SHA256) {
			digest_type = DNS_DSDIGEST_SHA256;
			break;
		}
	}

	for (result = dns_rdataset_first(&val->dlv);
	     result == ISC_R_SUCCESS;
	     result = dns_rdataset_next(&val->dlv))
	{
		dns_rdata_reset(&dlvrdata);
		dns_rdataset_current(&val->dlv, &dlvrdata);
		(void)dns_rdata_tostruct(&dlvrdata, &dlv, NULL);

		if (!dns_resolver_digest_supported(val->view->resolver,
						   dlv.digest_type))
			continue;
		
		if (dlv.digest_type != digest_type)
			continue;

		if (!dns_resolver_algorithm_supported(val->view->resolver,
						      val->event->name,
						      dlv.algorithm))
			continue;

		supported_algorithm = ISC_TRUE;

		dns_rdataset_init(&trdataset);
		dns_rdataset_clone(val->event->rdataset, &trdataset);

		for (result = dns_rdataset_first(&trdataset);
		     result == ISC_R_SUCCESS;
		     result = dns_rdataset_next(&trdataset))
		{
			dns_rdata_reset(&keyrdata);
			dns_rdataset_current(&trdataset, &keyrdata);
			(void)dns_rdata_tostruct(&keyrdata, &key, NULL);
			keytag = compute_keytag(&keyrdata, &key);
			if (dlv.key_tag != keytag ||
			    dlv.algorithm != key.algorithm)
				continue;
			dns_rdata_reset(&newdsrdata);
			result = dns_ds_buildrdata(val->event->name,
						   &keyrdata, dlv.digest_type,
						   dsbuf, &newdsrdata);
			if (result != ISC_R_SUCCESS) {
				validator_log(val, ISC_LOG_DEBUG(3),
					      "dns_ds_buildrdata() -> %s",
					      dns_result_totext(result));
				continue;
			}
			/* Covert to DLV */
			newdsrdata.type = dns_rdatatype_dlv;
			if (dns_rdata_compare(&dlvrdata, &newdsrdata) == 0)
				break;
		}
		if (result != ISC_R_SUCCESS) {
			validator_log(val, ISC_LOG_DEBUG(3),
				      "no DNSKEY matching DLV");
			continue;
		}
		validator_log(val, ISC_LOG_DEBUG(3),
		      "Found matching DLV record: checking for signature");

		for (result = dns_rdataset_first(val->event->sigrdataset);
		     result == ISC_R_SUCCESS;
		     result = dns_rdataset_next(val->event->sigrdataset))
		{
			dns_rdata_reset(&sigrdata);
			dns_rdataset_current(val->event->sigrdataset,
					     &sigrdata);
			(void)dns_rdata_tostruct(&sigrdata, &sig, NULL);
			if (dlv.key_tag != sig.keyid &&
			    dlv.algorithm != sig.algorithm)
				continue;
			dstkey = NULL;
			result = dns_dnssec_keyfromrdata(val->event->name,
							 &keyrdata,
							 val->view->mctx,
							 &dstkey);
			if (result != ISC_R_SUCCESS)
				/*
				 * This really shouldn't happen, but...
				 */
				continue;

			result = verify(val, dstkey, &sigrdata, sig.keyid);
			dst_key_free(&dstkey);
			if (result == ISC_R_SUCCESS)
				break;
		}
		dns_rdataset_disassociate(&trdataset);
		if (result == ISC_R_SUCCESS)
			break;
		validator_log(val, ISC_LOG_DEBUG(3),
			      "no RRSIG matching DLV key");
	}
	if (result == ISC_R_SUCCESS) {
		val->event->rdataset->trust = dns_trust_secure;
		val->event->sigrdataset->trust = dns_trust_secure;
		validator_log(val, ISC_LOG_DEBUG(3), "marking as secure");
		return (result);
	} else if (result == ISC_R_NOMORE && !supported_algorithm) {
		if (val->mustbesecure) {
			validator_log(val, ISC_LOG_WARNING,
				      "must be secure failure");
			return (DNS_R_MUSTBESECURE);
		}
		validator_log(val, ISC_LOG_DEBUG(3),
			      "no supported algorithm/digest (dlv)");
		markanswer(val);
		return (ISC_R_SUCCESS);
	} else
		return (DNS_R_NOVALIDSIG);
}

/*%
 * Attempts positive response validation of an RRset containing zone keys.
 *
 * Returns:
 * \li	ISC_R_SUCCESS	Validation completed successfully
 * \li	DNS_R_WAIT	Validation has started but is waiting
 *			for an event.
 * \li	Other return codes are possible and all indicate failure.
 */
static isc_result_t
validatezonekey(dns_validator_t *val) {
	isc_result_t result;
	dns_validatorevent_t *event;
	dns_rdataset_t trdataset;
	dns_rdata_t dsrdata = DNS_RDATA_INIT;
	dns_rdata_t newdsrdata = DNS_RDATA_INIT;
	dns_rdata_t keyrdata = DNS_RDATA_INIT;
	dns_rdata_t sigrdata = DNS_RDATA_INIT;
	unsigned char dsbuf[DNS_DS_BUFFERSIZE];
	char namebuf[DNS_NAME_FORMATSIZE];
	dns_keytag_t keytag;
	dns_rdata_ds_t ds;
	dns_rdata_dnskey_t key;
	dns_rdata_rrsig_t sig;
	dst_key_t *dstkey;
	isc_boolean_t supported_algorithm;
	isc_boolean_t atsep = ISC_FALSE;
	isc_uint8_t digest_type;

	/*
	 * Caller must be holding the validator lock.
	 */

	event = val->event;

	if (val->havedlvsep && val->dlv.trust >= dns_trust_secure &&
	    dns_name_equal(event->name, dns_fixedname_name(&val->dlvsep)))
		return (dlv_validatezonekey(val));

	if (val->dsset == NULL) {
		/*
		 * First, see if this key was signed by a trusted key.
		 */
		for (result = dns_rdataset_first(val->event->sigrdataset);
		     result == ISC_R_SUCCESS;
		     result = dns_rdataset_next(val->event->sigrdataset))
		{
			dns_keynode_t *keynode = NULL, *nextnode = NULL;

			dns_rdata_reset(&sigrdata);
			dns_rdataset_current(val->event->sigrdataset,
					     &sigrdata);
			(void)dns_rdata_tostruct(&sigrdata, &sig, NULL);
			result = dns_keytable_findkeynode(val->keytable,
							  val->event->name,
							  sig.algorithm,
							  sig.keyid,
							  &keynode);
			if (result == DNS_R_PARTIALMATCH ||
			    result == ISC_R_SUCCESS)
				atsep = ISC_TRUE;
			while (result == ISC_R_SUCCESS) {
				dstkey = dns_keynode_key(keynode);
				result = verify(val, dstkey, &sigrdata,
						sig.keyid);
				if (result == ISC_R_SUCCESS) {
					dns_keytable_detachkeynode(val->keytable,
								   &keynode);
					break;
				}
				result = dns_keytable_findnextkeynode(
								val->keytable,
								keynode,
								&nextnode);
				dns_keytable_detachkeynode(val->keytable,
							   &keynode);
				keynode = nextnode;
			}
			if (result == ISC_R_SUCCESS) {
				event->rdataset->trust = dns_trust_secure;
				event->sigrdataset->trust = dns_trust_secure;
				validator_log(val, ISC_LOG_DEBUG(3),
					      "signed by trusted key; "
					      "marking as secure");
				return (result);
			}
		}

		/*
		 * If this is the root name and there was no trusted key,
		 * give up, since there's no DS at the root.
		 */
		if (dns_name_equal(event->name, dns_rootname)) {
			if ((val->attributes & VALATTR_TRIEDVERIFY) != 0)
				return (DNS_R_NOVALIDSIG);
			else
				return (DNS_R_NOVALIDDS);
		}

		if (atsep) {
			/*
			 * We have not found a key to verify this DNSKEY
			 * RRset.  As this is a SEP we have to assume that
			 * the RRset is invalid.
			 */
			dns_name_format(val->event->name, namebuf,
				        sizeof(namebuf));
			validator_log(val, ISC_LOG_DEBUG(2),
				      "unable to find a DNSKEY which verifies "
				      "the DNSKEY RRset and also matches one "
				      "of specified trusted-keys for '%s'",
				      namebuf);
			return (DNS_R_NOVALIDKEY);
		}

		/*
		 * Otherwise, try to find the DS record.
		 */
		result = view_find(val, val->event->name, dns_rdatatype_ds);
		if (result == ISC_R_SUCCESS) {
			/*
			 * We have DS records.
			 */
			val->dsset = &val->frdataset;
			if (val->frdataset.trust == dns_trust_pending &&
			    dns_rdataset_isassociated(&val->fsigrdataset))
			{
				result = create_validator(val,
							  val->event->name,
							  dns_rdatatype_ds,
							  &val->frdataset,
							  &val->fsigrdataset,
							  dsvalidated,
							  "validatezonekey");
				if (result != ISC_R_SUCCESS)
					return (result);
				return (DNS_R_WAIT);
			} else if (val->frdataset.trust == dns_trust_pending) {
				/*
				 * There should never be an unsigned DS.
				 */
				dns_rdataset_disassociate(&val->frdataset);
				validator_log(val, ISC_LOG_DEBUG(2),
					      "unsigned DS record");
				return (DNS_R_NOVALIDSIG);
			} else
				result = ISC_R_SUCCESS;
		} else if (result == ISC_R_NOTFOUND) {
			/*
			 * We don't have the DS.  Find it.
			 */
			result = create_fetch(val, val->event->name,
					      dns_rdatatype_ds, dsfetched,
					      "validatezonekey");
			if (result != ISC_R_SUCCESS)
				return (result);
			return (DNS_R_WAIT);
		 } else if (result ==  DNS_R_NCACHENXDOMAIN ||
			   result == DNS_R_NCACHENXRRSET ||
			   result == DNS_R_NXDOMAIN ||
			   result == DNS_R_NXRRSET)
		{
			/*
			 * The DS does not exist.
			 */
			if (dns_rdataset_isassociated(&val->frdataset))
				dns_rdataset_disassociate(&val->frdataset);
			if (dns_rdataset_isassociated(&val->fsigrdataset))
				dns_rdataset_disassociate(&val->fsigrdataset);
			validator_log(val, ISC_LOG_DEBUG(2), "no DS record");
			return (DNS_R_NOVALIDSIG);
		}
	}

	/*
	 * We have a DS set.
	 */
	INSIST(val->dsset != NULL);

	if (val->dsset->trust < dns_trust_secure) {
		if (val->mustbesecure) {
			validator_log(val, ISC_LOG_WARNING,
				      "must be secure failure");
			return (DNS_R_MUSTBESECURE);
		}
		markanswer(val);
		return (ISC_R_SUCCESS);
	}

	/*
	 * Look through the DS record and find the keys that can sign the
	 * key set and the matching signature.  For each such key, attempt
	 * verification.
	 */

	supported_algorithm = ISC_FALSE;

	/*
	 * If DNS_DSDIGEST_SHA256 is present we are required to prefer
	 * it over DNS_DSDIGEST_SHA1.  This in practice means that we
	 * need to ignore DNS_DSDIGEST_SHA1 if a DNS_DSDIGEST_SHA256