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-rw-r--r--src/resolve/resolved-dns-dnssec.c108
-rw-r--r--src/resolve/resolved-dns-dnssec.h10
-rw-r--r--src/resolve/resolved-dns-transaction.c110
3 files changed, 201 insertions, 27 deletions
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
index 9930b56619..43fcbe1460 100644
--- a/src/resolve/resolved-dns-dnssec.c
+++ b/src/resolve/resolved-dns-dnssec.c
@@ -512,6 +512,7 @@ int dnssec_verify_rrset(
DnsResourceRecord **list, *rr;
gcry_md_hd_t md = NULL;
int r, md_algorithm;
+ bool wildcard = false;
size_t k, n = 0;
assert(key);
@@ -599,8 +600,10 @@ int dnssec_verify_rrset(
r = dns_name_suffix(DNS_RESOURCE_KEY_NAME(rr->key), rrsig->rrsig.labels, &suffix);
if (r < 0)
goto finish;
- if (r > 0) /* This is a wildcard! */
+ if (r > 0) /* This is a wildcard! */ {
gcry_md_write(md, (uint8_t[]) { 1, '*'}, 2);
+ wildcard = true;
+ }
r = dns_name_to_wire_format(suffix, wire_format_name, sizeof(wire_format_name), true);
if (r < 0)
@@ -651,7 +654,12 @@ int dnssec_verify_rrset(
if (r < 0)
goto finish;
- *result = r ? DNSSEC_VALIDATED : DNSSEC_INVALID;
+ if (!r)
+ *result = DNSSEC_INVALID;
+ else if (wildcard)
+ *result = DNSSEC_VALIDATED_WILDCARD;
+ else
+ *result = DNSSEC_VALIDATED;
r = 0;
finish:
@@ -748,7 +756,8 @@ int dnssec_verify_rrset_search(
const DnsResourceKey *key,
DnsAnswer *validated_dnskeys,
usec_t realtime,
- DnssecResult *result) {
+ DnssecResult *result,
+ DnsResourceRecord **ret_rrsig) {
bool found_rrsig = false, found_invalid = false, found_expired_rrsig = false, found_unsupported_algorithm = false;
DnsResourceRecord *rrsig;
@@ -808,13 +817,17 @@ int dnssec_verify_rrset_search(
switch (one_result) {
case DNSSEC_VALIDATED:
+ case DNSSEC_VALIDATED_WILDCARD:
/* Yay, the RR has been validated,
* return immediately, but fix up the expiry */
r = dnssec_fix_rrset_ttl(a, key, rrsig, realtime);
if (r < 0)
return r;
- *result = DNSSEC_VALIDATED;
+ if (ret_rrsig)
+ *ret_rrsig = rrsig;
+
+ *result = one_result;
return 0;
case DNSSEC_INVALID:
@@ -859,6 +872,9 @@ int dnssec_verify_rrset_search(
else
*result = DNSSEC_NO_SIGNATURE;
+ if (ret_rrsig)
+ *ret_rrsig = NULL;
+
return 0;
}
@@ -1501,7 +1517,7 @@ found_closest_encloser:
return 0;
}
-int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) {
+int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) {
DnsResourceRecord *rr;
bool have_nsec3 = false;
DnsAnswerFlags flags;
@@ -1570,8 +1586,90 @@ int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *r
return 0;
}
+int dnssec_nsec_test_between(DnsAnswer *answer, const char *name, const char *zone, bool *authenticated) {
+ DnsResourceRecord *rr;
+ DnsAnswerFlags flags;
+ int r;
+
+ assert(name);
+ assert(zone);
+
+ /* Checks whether there's an NSEC/NSEC3 that proves that the specified 'name' is non-existing in the specified
+ * 'zone'. The 'zone' must be a suffix of the 'name'. */
+
+ DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
+ bool found = false;
+
+ r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(rr->key), zone);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ continue;
+
+ switch (rr->key->type) {
+
+ case DNS_TYPE_NSEC:
+ r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), name, rr->nsec.next_domain_name);
+ if (r < 0)
+ return r;
+
+ found = r > 0;
+ break;
+
+ case DNS_TYPE_NSEC3: {
+ _cleanup_free_ char *hashed_domain = NULL, *next_hashed_domain = NULL;
+
+ r = nsec3_is_good(rr, NULL);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ /* Format the domain we are testing with the NSEC3 RR's hash function */
+ r = nsec3_hashed_domain_make(
+ rr,
+ name,
+ zone,
+ &hashed_domain);
+ if (r < 0)
+ return r;
+ if ((size_t) r != rr->nsec3.next_hashed_name_size)
+ break;
+
+ /* Format the NSEC3's next hashed name as proper domain name */
+ r = nsec3_hashed_domain_format(
+ rr->nsec3.next_hashed_name,
+ rr->nsec3.next_hashed_name_size,
+ zone,
+ &next_hashed_domain);
+ if (r < 0)
+ return r;
+
+ r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), hashed_domain, next_hashed_domain);
+ if (r < 0)
+ return r;
+
+ found = r > 0;
+ break;
+ }
+
+ default:
+ continue;
+ }
+
+ if (found) {
+ if (authenticated)
+ *authenticated = flags & DNS_ANSWER_AUTHENTICATED;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static const char* const dnssec_result_table[_DNSSEC_RESULT_MAX] = {
[DNSSEC_VALIDATED] = "validated",
+ [DNSSEC_VALIDATED_WILDCARD] = "validated-wildcard",
[DNSSEC_INVALID] = "invalid",
[DNSSEC_SIGNATURE_EXPIRED] = "signature-expired",
[DNSSEC_UNSUPPORTED_ALGORITHM] = "unsupported-algorithm",
diff --git a/src/resolve/resolved-dns-dnssec.h b/src/resolve/resolved-dns-dnssec.h
index 6977faca75..8a9bcf5b91 100644
--- a/src/resolve/resolved-dns-dnssec.h
+++ b/src/resolve/resolved-dns-dnssec.h
@@ -29,8 +29,9 @@ typedef enum DnssecResult DnssecResult;
#include "resolved-dns-rr.h"
enum DnssecResult {
- /* These four are returned by dnssec_verify_rrset() */
+ /* These five are returned by dnssec_verify_rrset() */
DNSSEC_VALIDATED,
+ DNSSEC_VALIDATED_WILDCARD, /* Validated via a wildcard RRSIG, further NSEC/NSEC3 checks necessary */
DNSSEC_INVALID,
DNSSEC_SIGNATURE_EXPIRED,
DNSSEC_UNSUPPORTED_ALGORITHM,
@@ -58,7 +59,7 @@ int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnske
int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig);
int dnssec_verify_rrset(DnsAnswer *answer, const DnsResourceKey *key, DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, usec_t realtime, DnssecResult *result);
-int dnssec_verify_rrset_search(DnsAnswer *answer, const DnsResourceKey *key, DnsAnswer *validated_dnskeys, usec_t realtime, DnssecResult *result);
+int dnssec_verify_rrset_search(DnsAnswer *answer, const DnsResourceKey *key, DnsAnswer *validated_dnskeys, usec_t realtime, DnssecResult *result, DnsResourceRecord **rrsig);
int dnssec_verify_dnskey(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke);
int dnssec_verify_dnskey_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds);
@@ -73,7 +74,7 @@ int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret);
typedef enum DnssecNsecResult {
DNSSEC_NSEC_NO_RR, /* No suitable NSEC/NSEC3 RR found */
- DNSSEC_NSEC_CNAME, /* Would be NODATA, but for the existence of a CNAME RR */
+ DNSSEC_NSEC_CNAME, /* Didn't find what was asked for, but did find CNAME */
DNSSEC_NSEC_UNSUPPORTED_ALGORITHM,
DNSSEC_NSEC_NXDOMAIN,
DNSSEC_NSEC_NODATA,
@@ -81,7 +82,8 @@ typedef enum DnssecNsecResult {
DNSSEC_NSEC_OPTOUT,
} DnssecNsecResult;
-int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl);
+int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl);
+int dnssec_nsec_test_between(DnsAnswer *answer, const char *name, const char *zone, bool *authenticated);
const char* dnssec_result_to_string(DnssecResult m) _const_;
DnssecResult dnssec_result_from_string(const char *s) _pure_;
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index 23378ce4f1..9a79a8e90d 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -2282,7 +2282,11 @@ static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) {
int dns_transaction_validate_dnssec(DnsTransaction *t) {
_cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL;
- bool dnskeys_finalized = false;
+ enum {
+ PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */
+ PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */
+ PHASE_ALL, /* Phase #3, validate everything else */
+ } phase;
DnsResourceRecord *rr;
DnsAnswerFlags flags;
int r;
@@ -2340,16 +2344,44 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
if (r < 0)
return r;
+ phase = PHASE_DNSKEY;
for (;;) {
- bool changed = false;
+ bool changed = false, have_nsec = false;
DNS_ANSWER_FOREACH(rr, t->answer) {
+ DnsResourceRecord *rrsig = NULL;
DnssecResult result;
- if (rr->key->type == DNS_TYPE_RRSIG)
+ switch (rr->key->type) {
+
+ case DNS_TYPE_RRSIG:
continue;
- r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result);
+ case DNS_TYPE_DNSKEY:
+ /* We validate DNSKEYs only in the DNSKEY and ALL phases */
+ if (phase == PHASE_NSEC)
+ continue;
+ break;
+
+ case DNS_TYPE_NSEC:
+ case DNS_TYPE_NSEC3:
+ have_nsec = true;
+
+ /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
+ if (phase == PHASE_DNSKEY)
+ continue;
+
+ break;
+
+ default:
+ /* We validate all other RRs only in the ALL phases */
+ if (phase != PHASE_ALL)
+ continue;
+
+ break;
+ }
+
+ r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig);
if (r < 0)
return r;
@@ -2393,13 +2425,52 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
break;
}
- /* If we haven't read all DNSKEYs yet a
- * negative result of the validation is
- * irrelevant, as there might be more DNSKEYs
- * coming. */
- if (!dnskeys_finalized)
+ /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
+ * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, we
+ * cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
+ if (phase != PHASE_ALL)
continue;
+ if (result == DNSSEC_VALIDATED_WILDCARD) {
+ bool authenticated = false;
+ const char *suffix;
+
+ /* This RRset validated, but as a wildcard. This means we need to proof via NSEC/NSEC3
+ * that no matching non-wildcard RR exists.
+ *
+ * See RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4*/
+
+ r = dns_name_suffix(DNS_RESOURCE_KEY_NAME(rr->key), rrsig->rrsig.labels, &suffix);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EBADMSG;
+
+ r = dns_name_parent(&suffix);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EBADMSG;
+
+ r = dnssec_nsec_test_between(validated, DNS_RESOURCE_KEY_NAME(rr->key), suffix, &authenticated);
+ if (r < 0)
+ return r;
+
+ /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
+ if (r == 0 || !authenticated)
+ result = DNSSEC_INVALID;
+
+ r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE);
+ if (r < 0)
+ return r;
+
+ t->scope->manager->n_dnssec_secure++;
+
+ /* Exit the loop, we dropped something from the answer, start from the beginning */
+ changed = true;
+ break;
+ }
+
if (result == DNSSEC_NO_SIGNATURE) {
r = dns_transaction_requires_rrsig(t, rr);
if (r < 0)
@@ -2519,17 +2590,20 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
break;
}
+ /* Restart the inner loop as long as we managed to achieve something */
if (changed)
continue;
- if (!dnskeys_finalized) {
- /* OK, now we know we have added all DNSKEYs
- * we possibly could to our validated
- * list. Now run the whole thing once more,
- * and strip everything we still cannot
- * validate.
- */
- dnskeys_finalized = true;
+ if (phase == PHASE_DNSKEY && have_nsec) {
+ /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
+ phase = PHASE_NSEC;
+ continue;
+ }
+
+ if (phase != PHASE_ALL) {
+ /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. Note that in this
+ * third phase we start to remove RRs we couldn't validate. */
+ phase = PHASE_ALL;
continue;
}
@@ -2565,7 +2639,7 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) {
bool authenticated = false;
/* Bummer! Let's check NSEC/NSEC3 */
- r = dnssec_test_nsec(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl);
+ r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl);
if (r < 0)
return r;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-09 22:59:46 +0000