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dnssec.c
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/*
* dnssec.c
*
* contains the cryptographic function needed for DNSSEC
* The crypto library used is openssl
*
* (c) NLnet Labs, 2004-2006
* a Net::DNS like library for C
*
* See the file LICENSE for the license
*/
#include <ldns/config.h>
#include <ldns/ldns.h>
#include <strings.h>
#include <time.h>
#ifdef HAVE_SSL
/* this entire file is rather useless when you don't have
* crypto...
*/
#include <openssl/ssl.h>
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/err.h>
#include <openssl/md5.h>
ldns_dnssec_data_chain *
ldns_dnssec_data_chain_new()
{
ldns_dnssec_data_chain *nc = LDNS_XMALLOC(ldns_dnssec_data_chain, 1);
nc->rrset = NULL;
nc->parent_type = 0;
nc->parent = NULL;
nc->signatures = NULL;
return nc;
}
void
ldns_dnssec_data_chain_free(ldns_dnssec_data_chain *chain)
{
LDNS_FREE(chain);
}
void
ldns_dnssec_data_chain_deep_free(ldns_dnssec_data_chain *chain)
{
ldns_rr_list_deep_free(chain->rrset);
ldns_rr_list_deep_free(chain->signatures);
if (chain->parent) {
ldns_dnssec_data_chain_deep_free(chain->parent);
}
LDNS_FREE(chain);
}
ldns_rr_list *
ldns_dnssec_pkt_get_rrsigs_for_type(const ldns_pkt *pkt, ldns_rdf *name, ldns_rr_type type)
{
uint16_t t_netorder;
ldns_rr_list *sigs;
ldns_rr_list *sigs_covered;
ldns_rdf *rdf_t;
sigs = ldns_pkt_rr_list_by_name_and_type(pkt,
name,
LDNS_RR_TYPE_RRSIG,
LDNS_SECTION_ANY_NOQUESTION
);
t_netorder = htons(type); /* rdf are in network order! */
rdf_t = ldns_rdf_new(LDNS_RDF_TYPE_TYPE, sizeof(ldns_rr_type), &t_netorder);
sigs_covered = ldns_rr_list_subtype_by_rdf(sigs, rdf_t, 0);
ldns_rdf_free(rdf_t);
ldns_rr_list_deep_free(sigs);
return sigs_covered;
}
void
ldns_dnssec_data_chain_print(FILE *out, const ldns_dnssec_data_chain *chain)
{
if (chain) {
ldns_dnssec_data_chain_print(out, chain->parent);
if (ldns_rr_list_rr_count(chain->rrset) > 0) {
ldns_rr_list_print(out, chain->rrset);
ldns_rr_list_print(out, chain->signatures);
fprintf(out, "---\n");
} else {
fprintf(out, "<no data>\n");
}
}
}
ldns_dnssec_data_chain *
ldns_dnssec_build_data_chain(ldns_resolver *res, uint16_t qflags, const ldns_rr_list *rrset, const ldns_pkt *pkt)
{
ldns_rr_list *signatures = NULL;
ldns_rr_list *keys;
ldns_rr_list *dss;
ldns_pkt *my_pkt;
ldns_rdf *name, *key_name = NULL;
ldns_rr_type type;
ldns_rr_class c;
ldns_dnssec_data_chain *new_chain = ldns_dnssec_data_chain_new();
if (!rrset || ldns_rr_list_rr_count(rrset) < 1) {
/* hmm, no data, do we have denial? only works if pkt was given,
otherwise caller has to do the check himself */
if (pkt) {
rrset = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_NSEC, LDNS_SECTION_ANY_NOQUESTION);
if (rrset && ldns_rr_list_rr_count(rrset) > 0) {
type = LDNS_RR_TYPE_NSEC;
} else {
/* nothing, stop */
return new_chain;
}
}
}
new_chain->rrset = ldns_rr_list_clone(rrset);
name = ldns_rr_owner(ldns_rr_list_rr(rrset, 0));
type = ldns_rr_get_type(ldns_rr_list_rr(rrset, 0));
c = ldns_rr_get_class(ldns_rr_list_rr(rrset, 0));
/* normally there will only be 1 signature 'set'
but there can be more than 1 denial (wildcards)
so check for NSEC
*/
if (type == LDNS_RR_TYPE_NSEC) {
/* just throw in all signatures, the tree builder must sort
this out */
if (pkt) {
/*signatures = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_RRSIG, LDNS_SECTION_ANY_NOQUESTION);*/
signatures = ldns_dnssec_pkt_get_rrsigs_for_type(pkt, name, type);
} else {
my_pkt = ldns_resolver_query(res, name, type, c, qflags);
signatures = ldns_pkt_rr_list_by_type(my_pkt, LDNS_RR_TYPE_RRSIG, LDNS_SECTION_ANY_NOQUESTION);
ldns_pkt_free(my_pkt);
}
} else {
if (pkt) {
signatures = ldns_dnssec_pkt_get_rrsigs_for_type(pkt, name, type);
}
if (!signatures) {
my_pkt = ldns_resolver_query(res, name, type, c, qflags);
signatures = ldns_dnssec_pkt_get_rrsigs_for_type(my_pkt, name, type);
ldns_pkt_free(my_pkt);
}
}
if (signatures && ldns_rr_list_rr_count(signatures) > 0) {
key_name = ldns_rr_rdf(ldns_rr_list_rr(signatures, 0), 7);
}
if (!key_name) {
/* apparently we were not able to find a signing key, so
we assume the chain ends here
*/
return new_chain;
}
if (type != LDNS_RR_TYPE_DNSKEY) {
if (signatures && ldns_rr_list_rr_count(signatures) > 0) {
new_chain->signatures = ldns_rr_list_clone(signatures);
new_chain->parent_type = 0;
keys = ldns_pkt_rr_list_by_name_and_type(pkt,
key_name,
LDNS_RR_TYPE_DNSKEY,
LDNS_SECTION_ANY_NOQUESTION
);
if (!keys) {
my_pkt = ldns_resolver_query(res, key_name, LDNS_RR_TYPE_DNSKEY, c, qflags);
keys = ldns_pkt_rr_list_by_name_and_type(my_pkt,
key_name,
LDNS_RR_TYPE_DNSKEY,
LDNS_SECTION_ANY_NOQUESTION
);
new_chain->parent = ldns_dnssec_build_data_chain(res, qflags, keys, my_pkt);
ldns_pkt_free(my_pkt);
} else {
new_chain->parent = ldns_dnssec_build_data_chain(res, qflags, keys, pkt);
}
ldns_rr_list_deep_free(keys);
}
} else {
/* 'self-signed', parent is a DS */
new_chain->parent_type = 1;
my_pkt = ldns_resolver_query(res, key_name, LDNS_RR_TYPE_DS, c, qflags);
dss = ldns_pkt_rr_list_by_name_and_type(my_pkt,
key_name,
LDNS_RR_TYPE_DS,
LDNS_SECTION_ANY_NOQUESTION
);
new_chain->parent = ldns_dnssec_build_data_chain(res, qflags, dss, my_pkt);
ldns_rr_list_deep_free(dss);
ldns_pkt_free(my_pkt);
}
if (signatures) {
ldns_rr_list_deep_free(signatures);
}
return new_chain;
}
ldns_dnssec_trust_tree *
ldns_dnssec_trust_tree_new()
{
ldns_dnssec_trust_tree *new_tree = LDNS_XMALLOC(ldns_dnssec_trust_tree, 1);
new_tree->rr = NULL;
new_tree->parent_count = 0;
return new_tree;
}
void
ldns_dnssec_trust_tree_free(ldns_dnssec_trust_tree *tree)
{
size_t i;
if (tree) {
for (i = 0; i < tree->parent_count; i++) {
ldns_dnssec_trust_tree_free(tree->parents[i]);
}
}
LDNS_FREE(tree);
}
ldns_status
ldns_dnssec_trust_tree_add_parent(ldns_dnssec_trust_tree *tree,
const ldns_dnssec_trust_tree *parent,
const ldns_rr *signature,
const ldns_status parent_status)
{
if (tree && parent && tree->parent_count < LDNS_DNSSEC_TRUST_TREE_MAX_PARENTS) {
tree->parents[tree->parent_count] = (ldns_dnssec_trust_tree *) parent;
tree->parent_status[tree->parent_count] = parent_status;
tree->parent_signature[tree->parent_count] = (ldns_rr *) signature;
tree->parent_count++;
return LDNS_STATUS_OK;
} else {
return LDNS_STATUS_ERR;
}
}
static void
print_tabs(FILE *out, size_t nr)
{
size_t i;
for (i = 0; i < nr; i++) {
fprintf(out, " ");
}
}
void
ldns_dnssec_trust_tree_print(FILE *out, ldns_dnssec_trust_tree *tree, size_t tabs, bool extended)
{
size_t i;
const ldns_rr_descriptor *descriptor;
if (tree) {
if (tree->rr) {
if (extended && tabs > 0) {
print_tabs(out, tabs - 1);
if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_DNSKEY) {
fprintf(out, "which is signed by:\n");
} else if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_DS) {
fprintf(out, "which matches:\n");
} else if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_NSEC) {
fprintf(out, "whose existence is denied by:\n");
}
} else {
if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_NSEC) {
fprintf(out, "Existence is denied by:\n");
}
}
print_tabs(out, tabs);
ldns_rdf_print(out, ldns_rr_owner(tree->rr));
descriptor = ldns_rr_descript(ldns_rr_get_type(tree->rr));
if (descriptor->_name) {
fprintf(out, " (%s", descriptor->_name);
} else {
fprintf(out, " (TYPE%d",
ldns_rr_get_type(tree->rr));
}
if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_DNSKEY) {
fprintf(out, " keytag: %u", ldns_calc_keytag(tree->rr));
}
fprintf(out, ")\n", tree->parent_count);
for (i = 0; i < tree->parent_count; i++) {
/* only print errors */
if (tree->parent_status[i] != LDNS_STATUS_OK) {
print_tabs(out, tabs + 1);
fprintf(out, "%s:\n", ldns_get_errorstr_by_id(tree->parent_status[i]));
print_tabs(out, tabs + 1);
ldns_rr_print(out, tree->parent_signature[i]);
print_tabs(out, tabs + 1);
fprintf(out, "from:\n");
}
ldns_dnssec_trust_tree_print(out, tree->parents[i], tabs+1, extended);
}
} else {
print_tabs(out, tabs);
fprintf(out, "<no data>\n");
}
} else {
fprintf(out, "<null pointer>\n");
}
}
void
ldns_dnssec_derive_trust_tree_normal_rrset(ldns_dnssec_trust_tree *new_tree,
ldns_dnssec_data_chain *data_chain,
ldns_rr *cur_sig_rr)
{
size_t j;
ldns_rr_list *cur_rrset = data_chain->rrset;
ldns_dnssec_trust_tree *cur_parent_tree;
ldns_rr *cur_parent_rr;
int cur_keytag;
ldns_rr_list *tmp_rrset;
ldns_status cur_status;
cur_keytag = ldns_rdf2native_int16(ldns_rr_rrsig_keytag(cur_sig_rr));
for (j = 0; j < ldns_rr_list_rr_count(data_chain->parent->rrset); j++) {
cur_parent_rr = ldns_rr_list_rr(data_chain->parent->rrset, j);
if (ldns_rr_get_type(cur_parent_rr) == LDNS_RR_TYPE_DNSKEY) {
if (ldns_calc_keytag(cur_parent_rr) == cur_keytag) {
cur_parent_tree = ldns_dnssec_derive_trust_tree(data_chain->parent, cur_parent_rr);
/* TODO: check wildcard nsec too */
if (ldns_rr_get_type(ldns_rr_list_rr(cur_rrset, 0)) == LDNS_RR_TYPE_NSEC) {
/* might contain different names! sort and split */
ldns_rr_list_sort(cur_rrset);
tmp_rrset = ldns_rr_list_pop_rrset(cur_rrset);
cur_rrset = tmp_rrset;
}
cur_status = ldns_verify_rrsig(cur_rrset, cur_sig_rr, cur_parent_rr);
ldns_dnssec_trust_tree_add_parent(new_tree, cur_parent_tree, cur_sig_rr, cur_status);
}
}
}
}
void
ldns_dnssec_derive_trust_tree_dnskey_rrset(ldns_dnssec_trust_tree *new_tree,
ldns_dnssec_data_chain *data_chain,
ldns_rr *cur_rr,
ldns_rr *cur_sig_rr)
{
size_t j;
ldns_rr_list *cur_rrset = data_chain->rrset;
ldns_dnssec_trust_tree *cur_parent_tree;
ldns_rr *cur_parent_rr;
int cur_keytag;
ldns_status cur_status;
cur_keytag = ldns_rdf2native_int16(ldns_rr_rrsig_keytag(cur_sig_rr));
for (j = 0; j < ldns_rr_list_rr_count(cur_rrset); j++) {
cur_parent_rr = ldns_rr_list_rr(cur_rrset, j);
if (cur_parent_rr != cur_rr &&
ldns_rr_get_type(cur_parent_rr) == LDNS_RR_TYPE_DNSKEY) {
if (ldns_calc_keytag(cur_parent_rr) == cur_keytag) {
cur_parent_tree = ldns_dnssec_derive_trust_tree(data_chain, cur_parent_rr);
cur_status = ldns_verify_rrsig(cur_rrset, cur_sig_rr, cur_parent_rr);
ldns_dnssec_trust_tree_add_parent(new_tree, cur_parent_tree, cur_sig_rr, LDNS_STATUS_OK);
}
}
}
}
void
ldns_dnssec_derive_trust_tree_ds_rrset(ldns_dnssec_trust_tree *new_tree,
ldns_dnssec_data_chain *data_chain,
ldns_rr *cur_rr)
{
size_t j, h;
ldns_rr_list *cur_rrset = data_chain->rrset;
ldns_dnssec_trust_tree *cur_parent_tree;
ldns_rr *cur_parent_rr;
int cur_keytag;
ldns_status cur_status;
/* try the parent to see whether there are DSs there */
if (ldns_rr_get_type(cur_rr) == LDNS_RR_TYPE_DNSKEY &&
data_chain->parent &&
data_chain->parent->rrset
) {
for (j = 0; j < ldns_rr_list_rr_count(data_chain->parent->rrset); j++) {
cur_parent_rr = ldns_rr_list_rr(data_chain->parent->rrset, j);
if (ldns_rr_get_type(cur_parent_rr) == LDNS_RR_TYPE_DS) {
for (h = 0; h < ldns_rr_list_rr_count(cur_rrset); h++) {
cur_rr = ldns_rr_list_rr(cur_rrset, h);
if (ldns_rr_compare_ds(cur_rr, cur_parent_rr)) {
cur_parent_tree = ldns_dnssec_derive_trust_tree(data_chain->parent, cur_parent_rr);
ldns_dnssec_trust_tree_add_parent(new_tree, cur_parent_tree, NULL, LDNS_STATUS_OK);
} else {
ldns_rr_print(stdout, cur_parent_rr);
}
}
cur_rr = ldns_rr_list_rr(cur_rrset, 0);
}
}
}
}
/* if rr is null, take the first from the rrset */
ldns_dnssec_trust_tree *
ldns_dnssec_derive_trust_tree(ldns_dnssec_data_chain *data_chain, ldns_rr *rr)
{
ldns_rr_list *cur_rrset, *tmp_rrset;
ldns_rr_list *cur_sigs;
ldns_rr *cur_rr = NULL;
ldns_rr *cur_parent_rr;
ldns_rr *cur_sig_rr;
uint16_t cur_keytag;
size_t h, i, j;
ldns_dnssec_trust_tree *cur_parent_tree;
ldns_dnssec_trust_tree *new_tree = ldns_dnssec_trust_tree_new();
ldns_status cur_status;
if (data_chain && data_chain->rrset) {
cur_rrset = data_chain->rrset;
cur_sigs = data_chain->signatures;
if (rr) {
cur_rr = rr;
}
if (!cur_rr && ldns_rr_list_rr_count(cur_rrset) > 0) {
cur_rr = ldns_rr_list_rr(cur_rrset, 0);
}
if (cur_rr) {
new_tree->rr = cur_rr;
/* there are three possibilities:
1 - 'normal' rrset, signed by a key
2 - dnskey signed by other dnskey
3 - dnskey proven by higher level DS
(data denied by nsec is a special case that can
occur in multiple places)
*/
for (i = 0; i < ldns_rr_list_rr_count(cur_sigs); i++) {
/* find the appropriate key in the parent list */
cur_sig_rr = ldns_rr_list_rr(cur_sigs, i);
cur_keytag = ldns_rdf2native_int16(ldns_rr_rrsig_keytag(cur_sig_rr));
if (ldns_rr_get_type(cur_rr) == LDNS_RR_TYPE_NSEC) {
if (ldns_dname_compare(ldns_rr_owner(cur_sig_rr),
ldns_rr_owner(cur_rr)))
{
printf("break\n");
break;
}
}
/* option 1 */
ldns_dnssec_derive_trust_tree_normal_rrset(new_tree, data_chain, cur_sig_rr);
/* option 2 */
ldns_dnssec_derive_trust_tree_dnskey_rrset(new_tree, data_chain, cur_rr, cur_sig_rr);
}
ldns_dnssec_derive_trust_tree_ds_rrset(new_tree, data_chain, cur_rr);
}
}
return new_tree;
}
/*
* returns OK if there is a path from tree to key with only OK
* the (first) error in between otherwise
* or NOT_FOUND if the key wasn't present at all
*/
ldns_status
ldns_dnssec_trust_tree_contains_keys(ldns_dnssec_trust_tree *tree, ldns_rr_list *trusted_keys)
{
size_t i;
ldns_status result = LDNS_STATUS_CRYPTO_NO_DNSKEY;
bool equal;
ldns_status parent_result;
if (tree && trusted_keys && ldns_rr_list_rr_count(trusted_keys) > 0)
{ if (tree->rr) {
for (i = 0; i < ldns_rr_list_rr_count(trusted_keys); i++) {
equal = ldns_rr_compare_ds(tree->rr, ldns_rr_list_rr(trusted_keys, i));
if (equal) {
result = LDNS_STATUS_OK;
return result;
}
}
}
for (i = 0; i < tree->parent_count; i++) {
parent_result = ldns_dnssec_trust_tree_contains_keys(tree->parents[i], trusted_keys);
if (parent_result != LDNS_STATUS_CRYPTO_NO_DNSKEY) {
if (tree->parent_status[i] != LDNS_STATUS_OK) {
result = tree->parent_status[i];
} else {
if (ldns_rr_get_type(tree->rr) == LDNS_RR_TYPE_NSEC &&
parent_result == LDNS_STATUS_OK
) {
result = LDNS_STATUS_DNSSEC_EXISTENCE_DENIED;
} else {
result = parent_result;
}
}
}
}
} else {
result = LDNS_STATUS_ERR;
}
return result;
}
/* used only on the public key RR */
uint16_t
ldns_calc_keytag(const ldns_rr *key)
{
unsigned int i;
uint32_t ac32;
uint16_t ac16;
ldns_buffer *keybuf;
size_t keysize;
if (!key) {
return 0;
}
ac32 = 0;
if (ldns_rr_get_type(key) != LDNS_RR_TYPE_DNSKEY) {
return 0;
}
/* rdata to buf - only put the rdata in a buffer */
keybuf = ldns_buffer_new(LDNS_MIN_BUFLEN); /* grows */
if (!keybuf) {
return 0;
}
(void)ldns_rr_rdata2buffer_wire(keybuf, key);
/* the current pos in the buffer is the keysize */
keysize= ldns_buffer_position(keybuf);
/* look at the algorithm field, copied from 2535bis */
if (ldns_rdf2native_int8(ldns_rr_rdf(key, 2)) == LDNS_RSAMD5) {
if (keysize > 4) {
ldns_buffer_read_at(keybuf, keysize - 3, &ac16, 2);
}
ldns_buffer_free(keybuf);
ac16 = ntohs(ac16);
return (uint16_t) ac16;
} else {
for (i = 0; (size_t)i < keysize; ++i) {
ac32 += (i & 1) ? *ldns_buffer_at(keybuf, i) :
*ldns_buffer_at(keybuf, i) << 8;
}
ldns_buffer_free(keybuf);
ac32 += (ac32 >> 16) & 0xFFFF;
/*printf("RETURNING %u\n", (uint16_t) (ac32 & 0xFFFF));*/
return (uint16_t) (ac32 & 0xFFFF);
}
}
ldns_status
ldns_verify(ldns_rr_list *rrset, ldns_rr_list *rrsig, const ldns_rr_list *keys,
ldns_rr_list *good_keys)
{
uint16_t i;
bool valid;
ldns_status verify_result = LDNS_STATUS_ERR;
if (!rrset || !rrsig || !keys) {
return LDNS_STATUS_ERR;
}
valid = false;
if (ldns_rr_list_rr_count(rrset) < 1) {
return LDNS_STATUS_ERR;
}
if (ldns_rr_list_rr_count(rrsig) < 1) {
return LDNS_STATUS_CRYPTO_NO_RRSIG;
}
if (ldns_rr_list_rr_count(keys) < 1) {
verify_result = LDNS_STATUS_CRYPTO_NO_TRUSTED_DNSKEY;
} else {
for (i = 0; i < ldns_rr_list_rr_count(rrsig); i++) {
if (ldns_verify_rrsig_keylist(rrset,
ldns_rr_list_rr(rrsig, i),
keys, good_keys) == LDNS_STATUS_OK) {
verify_result = LDNS_STATUS_OK;
}
}
}
return verify_result;
}
ldns_rr_list *
ldns_fetch_valid_domain_keys(const ldns_resolver * res, const ldns_rdf * domain, const ldns_rr_list * keys, ldns_status *status)
{
ldns_rr_list * trusted_keys = NULL;
ldns_rr_list * ds_keys = NULL;
if (res && domain && keys) {
if ((trusted_keys = ldns_validate_domain_dnskey(res, domain, keys))) {
*status = LDNS_STATUS_OK;
} else {
/* No trusted keys in this domain, we'll have to find some in the parent domain */
*status = LDNS_STATUS_CRYPTO_NO_TRUSTED_DNSKEY;
if (ldns_rdf_size(domain) > 1) { /* Fail if we are at the root */
ldns_rr_list * parent_keys;
ldns_rdf * parent_domain = ldns_dname_left_chop(domain);
if ((parent_keys = ldns_fetch_valid_domain_keys(res, parent_domain, keys, status))) {
printf("1\n");
/* Check DS records */
if ((ds_keys = ldns_validate_domain_ds(res, domain, parent_keys))) {
printf("2\n");
trusted_keys = ldns_fetch_valid_domain_keys(res, domain, ds_keys, status);
printf("[fetch_valid_domain_keys] trusted keys:\n");
ldns_rr_list_print(stdout, trusted_keys);
ldns_rr_list_deep_free(ds_keys);
} else {
/* No valid DS at the parent -- fail */
*status = LDNS_STATUS_CRYPTO_NO_TRUSTED_DS ;
}
ldns_rr_list_deep_free(parent_keys);
}
ldns_rdf_free(parent_domain);
}
else { printf("[fetch_valid_domain_keys] at root, nothing found\n"); }
}
}
else { printf("[fetch_valid_domain_keys] no res, domin or keys\n"); }
return trusted_keys;
}
ldns_rr_list *
ldns_validate_domain_dnskey (const ldns_resolver * res, const ldns_rdf * domain, const ldns_rr_list * keys)
{
ldns_status status;
ldns_pkt * keypkt;
ldns_rr * cur_key;
uint16_t key_i; uint16_t key_j; uint16_t key_k;
uint16_t sig_i; ldns_rr * cur_sig;
ldns_rr_list * domain_keys = NULL;
ldns_rr_list * domain_sigs = NULL;
ldns_rr_list * trusted_keys = NULL;
/* Fetch keys for the domain */
if ((keypkt = ldns_resolver_query(res, domain, LDNS_RR_TYPE_DNSKEY, LDNS_RR_CLASS_IN, LDNS_RD))) {
domain_keys = ldns_pkt_rr_list_by_type(keypkt, LDNS_RR_TYPE_DNSKEY, LDNS_SECTION_ANSWER);
domain_sigs = ldns_pkt_rr_list_by_type(keypkt, LDNS_RR_TYPE_RRSIG, LDNS_SECTION_ANSWER);
/* Try to validate the record using our keys */
for (key_i=0; key_i< ldns_rr_list_rr_count(domain_keys); key_i++) {
cur_key = ldns_rr_list_rr(domain_keys, key_i);
for (key_j=0; key_j<ldns_rr_list_rr_count(keys); key_j++) {
if (ldns_rr_compare_ds(ldns_rr_list_rr(keys, key_j), cur_key)) {
/* Current key is trusted -- validate */
trusted_keys = ldns_rr_list_new();
for (sig_i=0; sig_i<ldns_rr_list_rr_count(domain_sigs); sig_i++) {
cur_sig = ldns_rr_list_rr(domain_sigs, sig_i);
/* Avoid non-matching sigs */
if (ldns_rdf2native_int16(ldns_rr_rrsig_keytag(cur_sig)) == ldns_calc_keytag(cur_key)) {
if ((status=ldns_verify_rrsig(domain_keys, cur_sig, cur_key)) == LDNS_STATUS_OK) {
/* Push the whole rrset -- we can't do much more */
for (key_k=0; key_k<ldns_rr_list_rr_count(domain_keys); key_k++) {
ldns_rr_list_push_rr(trusted_keys, ldns_rr_clone(ldns_rr_list_rr(domain_keys, key_k)));
}
ldns_rr_list_deep_free(domain_keys);
ldns_rr_list_deep_free(domain_sigs);
ldns_pkt_free(keypkt);
return trusted_keys;
} /* else {
fprintf(stderr, "# Signature verification failed: %s\n", ldns_get_errorstr_by_id(status));
}
} else {
fprintf(stderr, "# Non-matching keytag for sig %u. Skipping.\n", sig_i);
*/
}
}
/* Only push our trusted key */
ldns_rr_list_push_rr(trusted_keys, ldns_rr_clone(cur_key));
}
}
}
ldns_rr_list_deep_free(domain_keys);
ldns_rr_list_deep_free(domain_sigs);
ldns_pkt_free(keypkt);
} else {
status = LDNS_STATUS_CRYPTO_NO_DNSKEY;
}
return trusted_keys;
}
ldns_rr_list *
ldns_validate_domain_ds (const ldns_resolver * res, const ldns_rdf * domain, const ldns_rr_list * keys)
{
ldns_status status;
ldns_pkt * dspkt;
uint16_t key_i;
ldns_rr_list * rrset = NULL;
ldns_rr_list * sigs = NULL;
ldns_rr_list * trusted_keys = NULL;
/* Fetch DS for the domain */
if ((dspkt = ldns_resolver_query(res, domain, LDNS_RR_TYPE_DS, LDNS_RR_CLASS_IN, LDNS_RD))) {
rrset = ldns_pkt_rr_list_by_type(dspkt, LDNS_RR_TYPE_DS, LDNS_SECTION_ANSWER);
sigs = ldns_pkt_rr_list_by_type(dspkt, LDNS_RR_TYPE_RRSIG, LDNS_SECTION_ANSWER);
/* Validate sigs */
if ((status = ldns_verify(rrset, sigs, keys, NULL)) == LDNS_STATUS_OK) {
trusted_keys = ldns_rr_list_new();
for (key_i=0; key_i<ldns_rr_list_rr_count(rrset); key_i++) {
ldns_rr_list_push_rr(trusted_keys, ldns_rr_clone(ldns_rr_list_rr(rrset, key_i)));
}
}
ldns_rr_list_deep_free(rrset);
ldns_rr_list_deep_free(sigs);
ldns_pkt_free(dspkt);
} else {
status = LDNS_STATUS_CRYPTO_NO_DS;
}
return trusted_keys;
}
#ifdef HAVE_SSL
ldns_status
ldns_verify_trusted(ldns_resolver * res, ldns_rr_list * rrset, ldns_rr_list * rrsigs, ldns_rr_list * validating_keys)
{
/* */
uint16_t sig_i; uint16_t key_i;
ldns_rr * cur_sig; ldns_rr * cur_key;
ldns_rr_list * trusted_keys = NULL;
ldns_status result = LDNS_STATUS_ERR;
printf("[verify_trusted] set default result to %s\n", ldns_get_errorstr_by_id(result));
if (!res || !rrset || !rrsigs) {
return LDNS_STATUS_ERR;
}
if (ldns_rr_list_rr_count(rrset) < 1) {
return LDNS_STATUS_ERR;
}
if (ldns_rr_list_rr_count(rrsigs) < 1) {
return LDNS_STATUS_CRYPTO_NO_RRSIG;
}
/* Look at each sig */
for (sig_i=0; sig_i < ldns_rr_list_rr_count(rrsigs); sig_i++) {
cur_sig = ldns_rr_list_rr(rrsigs, sig_i);
/* Get a valid signer key and validate the sig */
if ((trusted_keys = ldns_fetch_valid_domain_keys(res, ldns_rr_rrsig_signame(cur_sig), ldns_resolver_dnssec_anchors(res), &result))) {
for (key_i = 0; key_i < ldns_rr_list_rr_count(trusted_keys); key_i++) {
cur_key = ldns_rr_list_rr(trusted_keys, key_i);
printf("[verify_trusted] trying:\n[verify_trusted] ");
if ((result = ldns_verify_rrsig(rrset, cur_sig, cur_key)) == LDNS_STATUS_OK) {
if (validating_keys) {
ldns_rr_list_push_rr(validating_keys, ldns_rr_clone(cur_key));
}
ldns_rr_list_deep_free(trusted_keys);
printf("[verify_trusted] returning OK\n");
return LDNS_STATUS_OK;
}
else {
printf("RESULT: %s\nFOR:\n", ldns_get_errorstr_by_id(result));
ldns_rr_list_print(stdout, rrset);
ldns_rr_print(stdout, cur_sig);
ldns_rr_print(stdout, cur_key);
}
printf("[verify_trusted] set result to %s\n", ldns_get_errorstr_by_id(result));
}
}
else {
printf("[verify_trusted] no valid domain keys\n");
}
}
ldns_rr_list_deep_free(trusted_keys);
printf("[verify_trusted] returning: %s\n", ldns_get_errorstr_by_id(result));
return result;
}
#endif
ldns_status
ldns_verify_rrsig_buffers(ldns_buffer *rawsig_buf, ldns_buffer *verify_buf,
ldns_buffer *key_buf, uint8_t algo)
{
/* check for right key */
switch(algo) {
case LDNS_DSA:
return ldns_verify_rrsig_dsa(rawsig_buf, verify_buf, key_buf);
break;
case LDNS_RSASHA1:
/*return ldns_verify_rrsig_rsasha1(rawsig_buf, verify_buf, key_buf);*/
return ldns_verify_rrsig_rsasha1(rawsig_buf, verify_buf, key_buf);
break;
case LDNS_RSAMD5:
return ldns_verify_rrsig_rsamd5(rawsig_buf, verify_buf, key_buf);
break;
default:
/* do you know this alg?! */
return LDNS_STATUS_CRYPTO_UNKNOWN_ALGO;
}
}
/* Post 1.0 TODO: next 2 functions contain a lot of similar code */
/*
* to verify:
* - create the wire fmt of the b64 key rdata
* - create the wire fmt of the sorted rrset
* - create the wire fmt of the b64 sig rdata
* - create the wire fmt of the sig without the b64 rdata
* - cat the sig data (without b64 rdata) to the rrset
* - verify the rrset+sig, with the b64 data and the b64 key data
*/
ldns_status
ldns_verify_rrsig_keylist(ldns_rr_list *rrset, ldns_rr *rrsig, const ldns_rr_list *keys,
ldns_rr_list *good_keys)
{
ldns_buffer *rawsig_buf;
ldns_buffer *verify_buf;
ldns_buffer *key_buf;
uint32_t orig_ttl;
uint16_t i;
uint8_t sig_algo;
ldns_status result;
ldns_rr *current_key;
ldns_rr_list *rrset_clone;
ldns_rr_list *validkeys;
time_t now, inception, expiration;
uint8_t label_count;
ldns_rdf *wildcard_name;
ldns_rdf *wildcard_chopped;
ldns_rdf *wildcard_chopped_tmp;
if (!rrset) {
return LDNS_STATUS_ERR;
}
validkeys = ldns_rr_list_new();
if (!validkeys) {
return LDNS_STATUS_MEM_ERR;
}
/* canonicalize the sig */
ldns_dname2canonical(ldns_rr_owner(rrsig));
/* clone the rrset so that we can fiddle with it */
rrset_clone = ldns_rr_list_clone(rrset);
/* check if the typecovered is equal to the type checked */
if (ldns_rdf2rr_type(ldns_rr_rrsig_typecovered(rrsig)) !=
ldns_rr_get_type(ldns_rr_list_rr(rrset_clone, 0))) {
return LDNS_STATUS_CRYPTO_TYPE_COVERED_ERR;
}
/* create the buffers which will certainly hold the raw data */
rawsig_buf = ldns_buffer_new(LDNS_MAX_PACKETLEN);
verify_buf = ldns_buffer_new(LDNS_MAX_PACKETLEN);
sig_algo = ldns_rdf2native_int8(ldns_rr_rdf(rrsig, 1));
result = LDNS_STATUS_ERR;
/* check the signature time stamps */
inception = ldns_rdf2native_time_t(ldns_rr_rrsig_inception(rrsig));
expiration = ldns_rdf2native_time_t(ldns_rr_rrsig_expiration(rrsig));
now = time(NULL);
if (expiration - inception < 0) {
/* bad sig, expiration before inception?? Tsssg */
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_CRYPTO_EXPIRATION_BEFORE_INCEPTION;
}
if (now - inception < 0) {
/* bad sig, inception date has passed */
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_CRYPTO_SIG_NOT_INCEPTED;
}
if (expiration - now < 0) {
/* bad sig, expiration date has passed */
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_CRYPTO_SIG_EXPIRED;
}
/* create a buffer with b64 signature rdata */
if (ldns_rdf2buffer_wire(rawsig_buf, ldns_rr_rdf(rrsig, 8)) != LDNS_STATUS_OK) {
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_MEM_ERR;
}
orig_ttl = ldns_rdf2native_int32( ldns_rr_rdf(rrsig, 3));
label_count = ldns_rdf2native_int8(ldns_rr_rdf(rrsig, 2));
/* reset the ttl in the rrset with the orig_ttl from the sig */
/* and update owner name if it was wildcard */
for(i = 0; i < ldns_rr_list_rr_count(rrset_clone); i++) {
if (label_count <
ldns_dname_label_count(
ldns_rr_owner(ldns_rr_list_rr(rrset_clone, i)))) {
(void) ldns_str2rdf_dname(&wildcard_name, "*");
wildcard_chopped = ldns_rdf_clone(ldns_rr_owner(ldns_rr_list_rr(rrset_clone, i)));
while (label_count < ldns_dname_label_count(wildcard_chopped)) {
wildcard_chopped_tmp = ldns_dname_left_chop(wildcard_chopped);
ldns_rdf_deep_free(wildcard_chopped);
wildcard_chopped = wildcard_chopped_tmp;
}
(void) ldns_dname_cat(wildcard_name, wildcard_chopped);
ldns_rdf_deep_free(wildcard_chopped);
ldns_rdf_deep_free(ldns_rr_owner(ldns_rr_list_rr(rrset_clone, i)));
ldns_rr_set_owner(ldns_rr_list_rr(rrset_clone, i),
wildcard_name);
}
ldns_rr_set_ttl(ldns_rr_list_rr(rrset_clone, i), orig_ttl);
/* convert to lowercase */
ldns_rr2canonical(ldns_rr_list_rr(rrset_clone, i));
}
/* sort the rrset in canonical order */
ldns_rr_list_sort(rrset_clone);
/* put the signature rr (without the b64) to the verify_buf */
if (ldns_rrsig2buffer_wire(verify_buf, rrsig) != LDNS_STATUS_OK) {
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_MEM_ERR;
}
/* add the rrset in verify_buf */
if (ldns_rr_list2buffer_wire(verify_buf, rrset_clone) != LDNS_STATUS_OK) {
ldns_buffer_free(rawsig_buf);
ldns_buffer_free(verify_buf);
return LDNS_STATUS_MEM_ERR;
}
for(i = 0; i < ldns_rr_list_rr_count(keys); i++) {
current_key = ldns_rr_list_rr(keys, i);