diff options
| -rw-r--r-- | src/resolve/resolved-dns-dnssec.c | 158 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-rr.c | 58 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-rr.h | 14 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-transaction.c | 4 | ||||
| -rw-r--r-- | src/shared/dns-domain.c | 31 | ||||
| -rw-r--r-- | src/shared/dns-domain.h | 1 |
6 files changed, 206 insertions, 60 deletions
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c index b6fb362daa..37fc3150f0 100644 --- a/src/resolve/resolved-dns-dnssec.c +++ b/src/resolve/resolved-dns-dnssec.c @@ -430,6 +430,57 @@ static void md_add_uint32(gcry_md_hd_t md, uint32_t v) { gcry_md_write(md, &v, sizeof(v)); } +static int dnssec_rrsig_prepare(DnsResourceRecord *rrsig) { + int n_key_labels, n_signer_labels; + const char *name; + int r; + + /* Checks whether the specified RRSIG RR is somewhat valid, and initializes the .n_skip_labels_source and + * .n_skip_labels_signer fields so that we can use them later on. */ + + assert(rrsig); + assert(rrsig->key->type == DNS_TYPE_RRSIG); + + /* Check if this RRSIG RR is already prepared */ + if (rrsig->n_skip_labels_source != (unsigned) -1) + return 0; + + if (rrsig->rrsig.inception > rrsig->rrsig.expiration) + return -EINVAL; + + name = DNS_RESOURCE_KEY_NAME(rrsig->key); + + n_key_labels = dns_name_count_labels(name); + if (n_key_labels < 0) + return n_key_labels; + if (rrsig->rrsig.labels > n_key_labels) + return -EINVAL; + + n_signer_labels = dns_name_count_labels(rrsig->rrsig.signer); + if (n_signer_labels < 0) + return n_signer_labels; + if (n_signer_labels > rrsig->rrsig.labels) + return -EINVAL; + + r = dns_name_skip(name, n_key_labels - n_signer_labels, &name); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + /* Check if the signer is really a suffix of us */ + r = dns_name_equal(name, rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + rrsig->n_skip_labels_source = n_key_labels - rrsig->rrsig.labels; + rrsig->n_skip_labels_signer = n_key_labels - n_signer_labels; + + return 0; +} + static int dnssec_rrsig_expired(DnsResourceRecord *rrsig, usec_t realtime) { usec_t expiration, inception, skew; @@ -499,6 +550,35 @@ static int algorithm_to_gcrypt_md(uint8_t algorithm) { } } +static void dnssec_fix_rrset_ttl( + DnsResourceRecord *list[], + unsigned n, + DnsResourceRecord *rrsig, + usec_t realtime) { + + unsigned k; + + assert(list); + assert(n > 0); + assert(rrsig); + + for (k = 0; k < n; k++) { + DnsResourceRecord *rr = list[k]; + + /* Pick the TTL as the minimum of the RR's TTL, the + * RR's original TTL according to the RRSIG and the + * RRSIG's own TTL, see RFC 4035, Section 5.3.3 */ + rr->ttl = MIN3(rr->ttl, rrsig->rrsig.original_ttl, rrsig->ttl); + rr->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; + + /* Copy over information about the signer and wildcard source of synthesis */ + rr->n_skip_labels_source = rrsig->n_skip_labels_source; + rr->n_skip_labels_signer = rrsig->n_skip_labels_signer; + } + + rrsig->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; +} + int dnssec_verify_rrset( DnsAnswer *a, const DnsResourceKey *key, @@ -536,6 +616,14 @@ int dnssec_verify_rrset( if (md_algorithm < 0) return md_algorithm; + r = dnssec_rrsig_prepare(rrsig); + if (r == -EINVAL) { + *result = DNSSEC_INVALID; + return r; + } + if (r < 0) + return r; + r = dnssec_rrsig_expired(rrsig, realtime); if (r < 0) return r; @@ -699,12 +787,17 @@ int dnssec_verify_rrset( if (r < 0) goto finish; - if (!r) + /* Now, fix the ttl, expiry, and remember the synthesizing source and the signer */ + if (r > 0) + dnssec_fix_rrset_ttl(list, n, rrsig, realtime); + + if (r == 0) *result = DNSSEC_INVALID; else if (wildcard) *result = DNSSEC_VALIDATED_WILDCARD; else *result = DNSSEC_VALIDATED; + r = 0; finish: @@ -743,8 +836,6 @@ int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnske } int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) { - int r; - assert(key); assert(rrsig); @@ -757,45 +848,9 @@ int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) if (rrsig->rrsig.type_covered != key->type) return 0; - /* Make sure signer is a parent of the RRset */ - r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(rrsig->key), rrsig->rrsig.signer); - if (r <= 0) - return r; - - /* Make sure the owner name has at least as many labels as the "label" fields indicates. */ - r = dns_name_count_labels(DNS_RESOURCE_KEY_NAME(rrsig->key)); - if (r < 0) - return r; - if (r < rrsig->rrsig.labels) - return 0; - return dns_name_equal(DNS_RESOURCE_KEY_NAME(rrsig->key), DNS_RESOURCE_KEY_NAME(key)); } -static int dnssec_fix_rrset_ttl(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord *rrsig, usec_t realtime) { - DnsResourceRecord *rr; - int r; - - assert(key); - assert(rrsig); - - DNS_ANSWER_FOREACH(rr, a) { - r = dns_resource_key_equal(key, rr->key); - if (r < 0) - return r; - if (r == 0) - continue; - - /* Pick the TTL as the minimum of the RR's TTL, the - * RR's original TTL according to the RRSIG and the - * RRSIG's own TTL, see RFC 4035, Section 5.3.3 */ - rr->ttl = MIN3(rr->ttl, rrsig->rrsig.original_ttl, rrsig->ttl); - rr->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; - } - - return 0; -} - int dnssec_verify_rrset_search( DnsAnswer *a, const DnsResourceKey *key, @@ -865,10 +920,6 @@ int dnssec_verify_rrset_search( 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; - if (ret_rrsig) *ret_rrsig = rrsig; @@ -1658,15 +1709,17 @@ int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, const char *name if (rr->key->type != type && type != DNS_TYPE_ANY) continue; - 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: + + /* We only care for NSEC RRs from the indicated zone */ + r = dns_resource_record_is_signer(rr, zone); + if (r < 0) + return r; + if (r == 0) + continue; + r = dns_name_between(DNS_RESOURCE_KEY_NAME(rr->key), name, rr->nsec.next_domain_name); if (r < 0) return r; @@ -1677,6 +1730,13 @@ int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, const char *name case DNS_TYPE_NSEC3: { _cleanup_free_ char *hashed_domain = NULL, *next_hashed_domain = NULL; + /* We only care for NSEC3 RRs from the indicated zone */ + r = dns_resource_record_is_signer(rr, zone); + if (r < 0) + return r; + if (r == 0) + continue; + r = nsec3_is_good(rr, NULL); if (r < 0) return r; diff --git a/src/resolve/resolved-dns-rr.c b/src/resolve/resolved-dns-rr.c index dbf840157f..53fd708365 100644 --- a/src/resolve/resolved-dns-rr.c +++ b/src/resolve/resolved-dns-rr.c @@ -344,6 +344,7 @@ DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key) { rr->n_ref = 1; rr->key = dns_resource_key_ref(key); rr->expiry = USEC_INFINITY; + rr->n_skip_labels_signer = rr->n_skip_labels_source = (unsigned) -1; return rr; } @@ -1085,6 +1086,63 @@ int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical) { return 0; } +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; + + assert(rr); + assert(ret); + + /* Returns the RRset's signer, if it is known. */ + + if (rr->n_skip_labels_signer == (unsigned) -1) + return -ENODATA; + + n = DNS_RESOURCE_KEY_NAME(rr->key); + r = dns_name_skip(n, rr->n_skip_labels_signer, &n); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + *ret = n; + return 0; +} + +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; + + assert(rr); + assert(ret); + + /* Returns the RRset's synthesizing source, if it is known. */ + + if (rr->n_skip_labels_source == (unsigned) -1) + return -ENODATA; + + n = DNS_RESOURCE_KEY_NAME(rr->key); + r = dns_name_skip(n, rr->n_skip_labels_source, &n); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + *ret = n; + return 0; +} + +int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone) { + const char *signer; + int r; + + r = dns_resource_record_signer(rr, &signer); + if (r < 0) + return r; + + return dns_name_equal(zone, signer); +} + static void dns_resource_record_hash_func(const void *i, struct siphash *state) { const DnsResourceRecord *rr = i; diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h index fe29a41566..8e7bfaa7c7 100644 --- a/src/resolve/resolved-dns-rr.h +++ b/src/resolve/resolved-dns-rr.h @@ -108,14 +108,24 @@ struct DnsTxtItem { struct DnsResourceRecord { unsigned n_ref; DnsResourceKey *key; + char *to_string; + uint32_t ttl; usec_t expiry; /* RRSIG signature expiry */ + + /* How many labels to strip to determine "signer" of the RRSIG (aka, the zone). -1 if not signed. */ + unsigned n_skip_labels_signer; + /* How many labels to strip to determine "synthesizing source" of this RR, i.e. the wildcard's immediate parent. -1 if not signed. */ + unsigned n_skip_labels_source; + bool unparseable:1; + bool wire_format_canonical:1; void *wire_format; size_t wire_format_size; size_t wire_format_rdata_offset; + union { struct { void *data; @@ -296,6 +306,10 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref); int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical); +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone); + DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i); bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b); diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index c7d2d82ecf..8fe581b33c 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -2537,11 +2537,9 @@ int dns_transaction_validate_dnssec(DnsTransaction *t) { * that no matching non-wildcard RR exists.*/ /* First step, determine the source of synthesis */ - r = dns_name_suffix(DNS_RESOURCE_KEY_NAME(rr->key), rrsig->rrsig.labels, &source); + r = dns_resource_record_source(rrsig, &source); if (r < 0) return r; - if (r == 0) - return -EBADMSG; r = dnssec_test_positive_wildcard( validated, diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c index d1fb97fe92..ee0108715d 100644 --- a/src/shared/dns-domain.c +++ b/src/shared/dns-domain.c @@ -1189,6 +1189,26 @@ int dns_name_suffix(const char *name, unsigned n_labels, const char **ret) { return (int) (n - n_labels); } +int dns_name_skip(const char *a, unsigned n_labels, const char **ret) { + int r; + + assert(a); + assert(ret); + + for (; n_labels > 0; n_labels --) { + r = dns_name_parent(&a); + if (r < 0) + return r; + if (r == 0) { + *ret = ""; + return 0; + } + } + + *ret = a; + return 1; +} + int dns_name_count_labels(const char *name) { unsigned n = 0; const char *p; @@ -1219,14 +1239,9 @@ int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b) { assert(a); assert(b); - while (n_labels > 0) { - - r = dns_name_parent(&a); - if (r <= 0) - return r; - - n_labels --; - } + r = dns_name_skip(a, n_labels, &a); + if (r <= 0) + return r; return dns_name_equal(a, b); } diff --git a/src/shared/dns-domain.h b/src/shared/dns-domain.h index 4fbe0a618f..a679d40958 100644 --- a/src/shared/dns-domain.h +++ b/src/shared/dns-domain.h @@ -104,4 +104,5 @@ int dns_service_split(const char *joined, char **name, char **type, char **domai int dns_name_suffix(const char *name, unsigned n_labels, const char **ret); int dns_name_count_labels(const char *name); +int dns_name_skip(const char *a, unsigned n_labels, const char **ret); int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b); |