static int sign_ctx_add_self(dnssec_sign_ctx_t *ctx, const uint8_t *rdata)
{
assert(ctx);
assert(rdata);
int result;
// static header
dnssec_binary_t header = { 0 };
header.data = (uint8_t *)rdata;
header.size = RRSIG_RDATA_SIGNER_OFFSET;
result = dnssec_sign_add(ctx, &header);
if (result != DNSSEC_EOK) {
return result;
}
// signer name
const uint8_t *rdata_signer = rdata + RRSIG_RDATA_SIGNER_OFFSET;
dnssec_binary_t signer = { 0 };
signer.data = knot_dname_copy(rdata_signer, NULL);
signer.size = knot_dname_size(signer.data);
result = dnssec_sign_add(ctx, &signer);
free(signer.data);
return result;
}
/*----------------------------------------------------------------------------*/
_public_
int knot_edns_init(knot_rrset_t *opt_rr, uint16_t max_pld,
uint8_t ext_rcode, uint8_t ver, mm_ctx_t *mm)
{
if (opt_rr == NULL) {
return KNOT_EINVAL;
}
/* Initialize RRSet. */
knot_dname_t *owner = knot_dname_copy((const uint8_t*)"", mm);
if (owner == NULL) {
return KNOT_ENOMEM;
}
knot_rrset_init(opt_rr, owner, KNOT_RRTYPE_OPT, max_pld);
/* Create empty RDATA */
int ret = knot_rrset_add_rdata(opt_rr, NULL, 0, 0, mm);
if (ret == KNOT_EOK) {
knot_edns_set_ext_rcode(opt_rr, ext_rcode);
knot_edns_set_version(opt_rr, ver);
}
return ret;
}
static int answer_query(knot_pkt_t *pkt, pack_t *addr_set, struct kr_query *qry)
{
uint16_t rrtype = qry->stype;
uint16_t rrclass = qry->sclass;
if (rrtype != KNOT_RRTYPE_A && rrtype != KNOT_RRTYPE_AAAA) {
return kr_error(ENOENT);
}
knot_dname_t *qname = knot_dname_copy(qry->sname, &pkt->mm);
knot_rrset_t rr;
knot_rrset_init(&rr, qname, rrtype, rrclass);
int family_len = sizeof(struct in_addr);
if (rr.type == KNOT_RRTYPE_AAAA) {
family_len = sizeof(struct in6_addr);
}
/* Append address records from hints */
uint8_t *addr = pack_head(*addr_set);
while (addr != pack_tail(*addr_set)) {
size_t len = pack_obj_len(addr);
void *addr_val = pack_obj_val(addr);
if (len == family_len) {
knot_rrset_add_rdata(&rr, addr_val, len, 0, &pkt->mm);
}
addr = pack_obj_next(addr);
}
int ret = kr_error(ENOENT);
if (!knot_rrset_empty(&rr)) {
/* Update packet question */
if (!knot_dname_is_equal(knot_pkt_qname(pkt), qname)) {
KR_PKT_RECYCLE(pkt);
knot_pkt_put_question(pkt, qname, rrclass, rrtype);
}
/* Append to packet */
ret = knot_pkt_put(pkt, KNOT_COMPR_HINT_QNAME, &rr, KNOT_PF_FREE);
}
/* Clear RR if failed */
if (ret != 0) {
knot_rrset_clear(&rr, &pkt->mm);
}
return ret;
}
static int validate(knot_layer_t *ctx, knot_pkt_t *pkt)
{
int ret = 0;
struct kr_request *req = ctx->data;
struct kr_query *qry = req->current_query;
/* Ignore faulty or unprocessed responses. */
if (ctx->state & (KNOT_STATE_FAIL|KNOT_STATE_CONSUME)) {
return ctx->state;
}
/* Pass-through if user doesn't want secure answer or stub. */
/* @todo: Validating stub resolver mode. */
if (!(qry->flags & QUERY_DNSSEC_WANT) || (qry->flags & QUERY_STUB)) {
return ctx->state;
}
/* Answer for RRSIG may not set DO=1, but all records MUST still validate. */
bool use_signatures = (knot_pkt_qtype(pkt) != KNOT_RRTYPE_RRSIG);
if (!(qry->flags & QUERY_CACHED) && !knot_pkt_has_dnssec(pkt) && !use_signatures) {
DEBUG_MSG(qry, "<= got insecure response\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
/* Track difference between current TA and signer name.
* This indicates that the NS is auth for both parent-child, and we must update DS/DNSKEY to validate it.
*/
const bool track_pc_change = (!(qry->flags & QUERY_CACHED) && (qry->flags & QUERY_DNSSEC_WANT));
const knot_dname_t *ta_name = qry->zone_cut.trust_anchor ? qry->zone_cut.trust_anchor->owner : NULL;
const knot_dname_t *signer = signature_authority(pkt);
if (track_pc_change && ta_name && (!signer || !knot_dname_is_equal(ta_name, signer))) {
if (ctx->state == KNOT_STATE_YIELD) { /* Already yielded for revalidation. */
return KNOT_STATE_FAIL;
}
DEBUG_MSG(qry, ">< cut changed, needs revalidation\n");
if (!signer) {
/* Not a DNSSEC-signed response, ask parent for DS to prove transition to INSECURE. */
} else if (knot_dname_is_sub(signer, qry->zone_cut.name)) {
/* Key signer is below current cut, advance and refetch keys. */
qry->zone_cut.name = knot_dname_copy(signer, &req->pool);
} else if (!knot_dname_is_equal(signer, qry->zone_cut.name)) {
/* Key signer is above the current cut, so we can't validate it. This happens when
a server is authoritative for both grandparent, parent and child zone.
Ascend to parent cut, and refetch authority for signer. */
if (qry->zone_cut.parent) {
memcpy(&qry->zone_cut, qry->zone_cut.parent, sizeof(qry->zone_cut));
} else {
qry->flags |= QUERY_AWAIT_CUT;
}
qry->zone_cut.name = knot_dname_copy(signer, &req->pool);
} /* else zone cut matches, but DS/DNSKEY doesn't => refetch. */
return KNOT_STATE_YIELD;
}
/* Check if this is a DNSKEY answer, check trust chain and store. */
uint8_t pkt_rcode = knot_wire_get_rcode(pkt->wire);
uint16_t qtype = knot_pkt_qtype(pkt);
bool has_nsec3 = pkt_has_type(pkt, KNOT_RRTYPE_NSEC3);
if (knot_wire_get_aa(pkt->wire) && qtype == KNOT_RRTYPE_DNSKEY) {
ret = validate_keyset(qry, pkt, has_nsec3);
if (ret != 0) {
DEBUG_MSG(qry, "<= bad keys, broken trust chain\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* Validate non-existence proof if not positive answer. */
if (!(qry->flags & QUERY_CACHED) && pkt_rcode == KNOT_RCODE_NXDOMAIN) {
/* @todo If knot_pkt_qname(pkt) is used instead of qry->sname then the tests crash. */
if (!has_nsec3) {
ret = kr_nsec_name_error_response_check(pkt, KNOT_AUTHORITY, qry->sname);
} else {
ret = kr_nsec3_name_error_response_check(pkt, KNOT_AUTHORITY, qry->sname);
}
if (ret != 0) {
DEBUG_MSG(qry, "<= bad NXDOMAIN proof\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* @todo WTH, this needs API that just tries to find a proof and the caller
* doesn't have to worry about NSEC/NSEC3
* @todo rework this */
if (!(qry->flags & QUERY_CACHED)) {
const knot_pktsection_t *an = knot_pkt_section(pkt, KNOT_ANSWER);
if (pkt_rcode == KNOT_RCODE_NOERROR && an->count == 0 && knot_wire_get_aa(pkt->wire)) {
/* @todo
* ? quick mechanism to determine which check to preform first
* ? merge the functionality together to share code/resources
*/
if (!has_nsec3) {
ret = kr_nsec_existence_denial(pkt, KNOT_AUTHORITY, knot_pkt_qname(pkt), knot_pkt_qtype(pkt));
} else {
ret = kr_nsec3_no_data(pkt, KNOT_AUTHORITY, knot_pkt_qname(pkt), knot_pkt_qtype(pkt));
}
if (ret != 0) {
if (has_nsec3 && (ret == kr_error(DNSSEC_NOT_FOUND))) {
DEBUG_MSG(qry, "<= can't prove NODATA due to optout, going insecure\n");
qry->flags &= ~QUERY_DNSSEC_WANT;
qry->flags |= QUERY_DNSSEC_INSECURE;
} else {
DEBUG_MSG(qry, "<= bad NODATA proof\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
}
}
/* Validate all records, fail as bogus if it doesn't match.
* Do not revalidate data from cache, as it's already trusted. */
if (!(qry->flags & QUERY_CACHED)) {
ret = validate_records(qry, pkt, req->rplan.pool, has_nsec3);
if (ret != 0) {
DEBUG_MSG(qry, "<= couldn't validate RRSIGs\n");
qry->flags |= QUERY_DNSSEC_BOGUS;
return KNOT_STATE_FAIL;
}
}
/* Check if wildcard expansion detected for final query.
* If yes, copy authority. */
if ((qry->parent == NULL) && (qry->flags & QUERY_DNSSEC_WEXPAND)) {
const knot_pktsection_t *auth = knot_pkt_section(pkt, KNOT_AUTHORITY);
for (unsigned i = 0; i < auth->count; ++i) {
const knot_rrset_t *rr = knot_pkt_rr(auth, i);
kr_rrarray_add(&req->authority, rr, &req->answer->mm);
}
}
/* Check and update current delegation point security status. */
ret = update_delegation(req, qry, pkt, has_nsec3);
if (ret != 0) {
return KNOT_STATE_FAIL;
}
/* Update parent query zone cut */
if (qry->parent) {
if (update_parent_keys(qry, qtype) != 0) {
return KNOT_STATE_FAIL;
}
}
DEBUG_MSG(qry, "<= answer valid, OK\n");
return KNOT_STATE_DONE;
}