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path: root/src/resolve/resolved-dns-dnssec.c
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Diffstat (limited to 'src/resolve/resolved-dns-dnssec.c')
-rw-r--r--src/resolve/resolved-dns-dnssec.c283
1 files changed, 204 insertions, 79 deletions
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
index ed126505ad..814cb1c0f9 100644
--- a/src/resolve/resolved-dns-dnssec.c
+++ b/src/resolve/resolved-dns-dnssec.c
@@ -35,16 +35,13 @@
*
* TODO:
*
- * - Iterative validation
- * - NSEC proof of non-existance
- * - NSEC3 proof of non-existance
* - Make trust anchor store read additional DS+DNSKEY data from disk
* - wildcard zones compatibility
* - multi-label zone compatibility
- * - DNSSEC cname/dname compatibility
+ * - cname/dname compatibility
* - per-interface DNSSEC setting
- * - retry on failed validation
* - fix TTL for cache entries to match RRSIG TTL
+ * - retry on failed validation?
* - DSA support
* - EC support?
*
@@ -499,7 +496,7 @@ int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnske
return dns_name_equal(DNS_RESOURCE_KEY_NAME(dnskey->key), rrsig->rrsig.signer);
}
-int dnssec_key_match_rrsig(DnsResourceKey *key, DnsResourceRecord *rrsig) {
+int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) {
assert(key);
assert(rrsig);
@@ -529,7 +526,7 @@ int dnssec_verify_rrset_search(
assert(key);
assert(result);
- /* Verifies all RRs from "a" that match the key "key", against DNSKEY and DS RRs in "validated_dnskeys" */
+ /* Verifies all RRs from "a" that match the key "key" against DNSKEYs in "validated_dnskeys" */
if (!a || a->n_rrs <= 0)
return -ENODATA;
@@ -537,6 +534,7 @@ int dnssec_verify_rrset_search(
/* Iterate through each RRSIG RR. */
DNS_ANSWER_FOREACH(rrsig, a) {
DnsResourceRecord *dnskey;
+ DnsAnswerFlags flags;
/* Is this an RRSIG RR that applies to RRs matching our key? */
r = dnssec_key_match_rrsig(key, rrsig);
@@ -548,9 +546,12 @@ int dnssec_verify_rrset_search(
found_rrsig = true;
/* Look for a matching key */
- DNS_ANSWER_FOREACH(dnskey, validated_dnskeys) {
+ DNS_ANSWER_FOREACH_FLAGS(dnskey, flags, validated_dnskeys) {
DnssecResult one_result;
+ if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
+ continue;
+
/* Is this a DNSKEY RR that matches they key of our RRSIG? */
r = dnssec_rrsig_match_dnskey(rrsig, dnskey);
if (r < 0)
@@ -626,6 +627,23 @@ int dnssec_verify_rrset_search(
return 0;
}
+int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) {
+ DnsResourceRecord *rr;
+ int r;
+
+ /* Checks whether there's at least one RRSIG in 'a' that proctects RRs of the specified key */
+
+ DNS_ANSWER_FOREACH(rr, a) {
+ r = dnssec_key_match_rrsig(key, rr);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ return 1;
+ }
+
+ return 0;
+}
+
int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) {
size_t c = 0;
int r;
@@ -776,6 +794,7 @@ finish:
int dnssec_verify_dnskey_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) {
DnsResourceRecord *ds;
+ DnsAnswerFlags flags;
int r;
assert(dnskey);
@@ -783,7 +802,10 @@ int dnssec_verify_dnskey_search(DnsResourceRecord *dnskey, DnsAnswer *validated_
if (dnskey->key->type != DNS_TYPE_DNSKEY)
return 0;
- DNS_ANSWER_FOREACH(ds, validated_ds) {
+ DNS_ANSWER_FOREACH_FLAGS(ds, flags, validated_ds) {
+
+ if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
+ continue;
if (ds->key->type != DNS_TYPE_DS)
continue;
@@ -866,114 +888,218 @@ finish:
return r;
}
-int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result) {
+static int dnssec_test_nsec3(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result) {
+ _cleanup_free_ char *next_closer_domain = NULL, *l = NULL;
+ uint8_t hashed[DNSSEC_HASH_SIZE_MAX];
+ const char *p, *pp = NULL;
DnsResourceRecord *rr;
- int r;
+ DnsAnswerFlags flags;
+ int hashed_size, r;
assert(key);
assert(result);
- /* Look for any NSEC/NSEC3 RRs that say something about the specified key. */
-
- DNS_ANSWER_FOREACH(rr, answer) {
+ /* First step, look for the closest encloser NSEC3 RR in 'answer' that matches 'key' */
+ p = DNS_RESOURCE_KEY_NAME(key);
+ for (;;) {
+ DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
+ _cleanup_free_ char *hashed_domain = NULL, *label = NULL;
- if (rr->key->class != key->class)
- continue;
+ if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
+ continue;
- switch (rr->key->type) {
+ if (rr->key->type != DNS_TYPE_NSEC3)
+ continue;
- case DNS_TYPE_NSEC:
+ /* RFC 5155, Section 8.2 says we MUST ignore NSEC3 RRs with flags != 0 or 1 */
+ if (!IN_SET(rr->nsec3.flags, 0, 1))
+ continue;
- r = dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key));
+ r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(rr->key), p);
if (r < 0)
return r;
- if (r > 0) {
- *result = bitmap_isset(rr->nsec.types, key->type) ? DNSSEC_NSEC_FOUND : DNSSEC_NSEC_NODATA;
+ if (r == 0)
+ continue;
+
+ hashed_size = dnssec_nsec3_hash(rr, p, hashed);
+ if (hashed_size == -EOPNOTSUPP) {
+ *result = DNSSEC_NSEC_UNSUPPORTED_ALGORITHM;
return 0;
}
+ if (hashed_size < 0)
+ return hashed_size;
+ if (rr->nsec3.next_hashed_name_size != (size_t) hashed_size)
+ return -EBADMSG;
- r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key), rr->nsec.next_domain_name);
+ label = base32hexmem(hashed, hashed_size, false);
+ if (!label)
+ return -ENOMEM;
+
+ hashed_domain = strjoin(label, ".", p, NULL);
+ if (!hashed_domain)
+ return -ENOMEM;
+
+ r = dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), hashed_domain);
if (r < 0)
return r;
- if (r > 0) {
- *result = DNSSEC_NSEC_NXDOMAIN;
- return 0;
- }
+ if (r > 0)
+ goto found;
+ }
+
+ /* We didn't find the closest encloser with this name,
+ * but let's remember this domain name, it might be
+ * the next closer name */
+
+ pp = p;
+
+ /* Strip one label from the front */
+ r = dns_name_parent(&p);
+ if (r < 0)
+ return r;
+ if (r == 0)
break;
+ }
- case DNS_TYPE_NSEC3: {
- _cleanup_free_ void *decoded = NULL;
- size_t decoded_size;
- char label[DNS_LABEL_MAX];
- uint8_t hashed[DNSSEC_HASH_SIZE_MAX];
- int label_length, c, q;
- const char *p;
- bool covered;
+ *result = DNSSEC_NSEC_NO_RR;
+ return 0;
- /* RFC 5155, Section 8.2 says we MUST ignore NSEC3 RRs with flags != 0 or 1 */
- if (!IN_SET(rr->nsec3.flags, 0, 1))
- continue;
+found:
+ /* We found a closest encloser in 'p'; next closer is 'pp' */
- p = DNS_RESOURCE_KEY_NAME(rr->key);
- label_length = dns_label_unescape(&p, label, sizeof(label));
- if (label_length < 0)
- return label_length;
- if (label_length == 0)
- continue;
+ /* Ensure this is not a DNAME domain, see RFC5155, section 8.3. */
+ if (bitmap_isset(rr->nsec3.types, DNS_TYPE_DNAME))
+ return -EBADMSG;
- r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), p);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
+ /* Ensure that this data is from the delegated domain
+ * (i.e. originates from the "lower" DNS server), and isn't
+ * just glue records (i.e. doesn't originate from the "upper"
+ * DNS server). */
+ if (bitmap_isset(rr->nsec3.types, DNS_TYPE_NS) &&
+ !bitmap_isset(rr->nsec3.types, DNS_TYPE_SOA))
+ return -EBADMSG;
- r = unbase32hexmem(label, label_length, false, &decoded, &decoded_size);
- if (r == -EINVAL)
- continue;
- if (r < 0)
- return r;
+ if (!pp) {
+ /* No next closer NSEC3 RR. That means there's a direct NSEC3 RR for our key. */
+ *result = bitmap_isset(rr->nsec3.types, key->type) ? DNSSEC_NSEC_FOUND : DNSSEC_NSEC_NODATA;
+ return 0;
+ }
- if (decoded_size != rr->nsec3.next_hashed_name_size)
- continue;
+ r = dnssec_nsec3_hash(rr, pp, hashed);
+ if (r < 0)
+ return r;
+ if (r != hashed_size)
+ return -EBADMSG;
- c = memcmp(decoded, rr->nsec3.next_hashed_name, decoded_size);
- if (c == 0)
- continue;
+ l = base32hexmem(hashed, hashed_size, false);
+ if (!l)
+ return -ENOMEM;
- r = dnssec_nsec3_hash(rr, DNS_RESOURCE_KEY_NAME(key), hashed);
- /* RFC 5155, Section 8.1 says we MUST ignore NSEC3 RRs with unknown algorithms */
- if (r == -EOPNOTSUPP)
- continue;
- if (r < 0)
- return r;
- if ((size_t) r != decoded_size)
- continue;
+ next_closer_domain = strjoin(l, ".", p, NULL);
+ if (!next_closer_domain)
+ return -ENOMEM;
- r = memcmp(decoded, hashed, decoded_size);
- if (r == 0) {
- *result = bitmap_isset(rr->nsec3.types, key->type) ? DNSSEC_NSEC_FOUND : DNSSEC_NSEC_NODATA;
- return 0;
- }
+ DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
+ _cleanup_free_ char *label = NULL, *next_hashed_domain = NULL;
+ const char *nsec3_parent;
+
+ if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
+ continue;
- q = memcmp(hashed, rr->nsec3.next_hashed_name, decoded_size);
+ if (rr->key->type != DNS_TYPE_NSEC3)
+ continue;
- covered = c < 0 ?
- r < 0 && q < 0 :
- q < 0 || r < 0;
+ /* RFC 5155, Section 8.2 says we MUST ignore NSEC3 RRs with flags != 0 or 1 */
+ if (!IN_SET(rr->nsec3.flags, 0, 1))
+ continue;
- if (covered) {
+ nsec3_parent = DNS_RESOURCE_KEY_NAME(rr->key);
+ r = dns_name_parent(&nsec3_parent);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ continue;
+
+ r = dns_name_equal(p, nsec3_parent);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ continue;
+
+ label = base32hexmem(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, false);
+ if (!label)
+ return -ENOMEM;
+
+ next_hashed_domain = strjoin(label, ".", p, NULL);
+ if (!next_hashed_domain)
+ return -ENOMEM;
+
+ r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), next_closer_domain, next_hashed_domain);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ if (rr->nsec3.flags & 1)
+ *result = DNSSEC_NSEC_OPTOUT;
+ else
*result = DNSSEC_NSEC_NXDOMAIN;
+
+ return 1;
+ }
+ }
+
+ *result = DNSSEC_NSEC_NO_RR;
+ return 0;
+}
+
+int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result) {
+ DnsResourceRecord *rr;
+ bool have_nsec3 = false;
+ DnsAnswerFlags flags;
+ int r;
+
+ assert(key);
+ assert(result);
+
+ /* Look for any NSEC/NSEC3 RRs that say something about the specified key. */
+
+ DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
+
+ if (rr->key->class != key->class)
+ continue;
+
+ if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
+ continue;
+
+ switch (rr->key->type) {
+
+ case DNS_TYPE_NSEC:
+
+ r = dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key));
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ *result = bitmap_isset(rr->nsec.types, key->type) ? DNSSEC_NSEC_FOUND : DNSSEC_NSEC_NODATA;
return 0;
}
+ r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key), rr->nsec.next_domain_name);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ *result = DNSSEC_NSEC_NXDOMAIN;
+ return 0;
+ }
break;
- }
- default:
+ case DNS_TYPE_NSEC3:
+ have_nsec3 = true;
break;
}
}
+ /* OK, this was not sufficient. Let's see if NSEC3 can help. */
+ if (have_nsec3)
+ return dnssec_test_nsec3(answer, key, result);
+
/* No approproate NSEC RR found, report this. */
*result = DNSSEC_NSEC_NO_RR;
return 0;
@@ -981,7 +1107,6 @@ int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *r
static const char* const dnssec_mode_table[_DNSSEC_MODE_MAX] = {
[DNSSEC_NO] = "no",
- [DNSSEC_TRUST] = "trust",
[DNSSEC_YES] = "yes",
};
DEFINE_STRING_TABLE_LOOKUP(dnssec_mode, DnssecMode);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-28 07:36:50 +0000