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-rw-r--r--src/resolve/resolved-dns-dnssec.c2199
1 files changed, 0 insertions, 2199 deletions
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
deleted file mode 100644
index d4a267c89f..0000000000
--- a/src/resolve/resolved-dns-dnssec.c
+++ /dev/null
@@ -1,2199 +0,0 @@
-/***
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#ifdef HAVE_GCRYPT
-#include <gcrypt.h>
-#endif
-
-#include "alloc-util.h"
-#include "dns-domain.h"
-#include "gcrypt-util.h"
-#include "hexdecoct.h"
-#include "resolved-dns-dnssec.h"
-#include "resolved-dns-packet.h"
-#include "string-table.h"
-
-#define VERIFY_RRS_MAX 256
-#define MAX_KEY_SIZE (32*1024)
-
-/* Permit a maximum clock skew of 1h 10min. This should be enough to deal with DST confusion */
-#define SKEW_MAX (1*USEC_PER_HOUR + 10*USEC_PER_MINUTE)
-
-/* Maximum number of NSEC3 iterations we'll do. RFC5155 says 2500 shall be the maximum useful value */
-#define NSEC3_ITERATIONS_MAX 2500
-
-/*
- * The DNSSEC Chain of trust:
- *
- * Normal RRs are protected via RRSIG RRs in combination with DNSKEY RRs, all in the same zone
- * DNSKEY RRs are either protected like normal RRs, or via a DS from a zone "higher" up the tree
- * DS RRs are protected like normal RRs
- *
- * Example chain:
- * Normal RR → RRSIG/DNSKEY+ → DS → RRSIG/DNSKEY+ → DS → ... → DS → RRSIG/DNSKEY+ → DS
- */
-
-uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke) {
- const uint8_t *p;
- uint32_t sum, f;
- size_t i;
-
- /* The algorithm from RFC 4034, Appendix B. */
-
- assert(dnskey);
- assert(dnskey->key->type == DNS_TYPE_DNSKEY);
-
- f = (uint32_t) dnskey->dnskey.flags;
-
- if (mask_revoke)
- f &= ~DNSKEY_FLAG_REVOKE;
-
- sum = f + ((((uint32_t) dnskey->dnskey.protocol) << 8) + (uint32_t) dnskey->dnskey.algorithm);
-
- p = dnskey->dnskey.key;
-
- for (i = 0; i < dnskey->dnskey.key_size; i++)
- sum += (i & 1) == 0 ? (uint32_t) p[i] << 8 : (uint32_t) p[i];
-
- sum += (sum >> 16) & UINT32_C(0xFFFF);
-
- return sum & UINT32_C(0xFFFF);
-}
-
-int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) {
- size_t c = 0;
- int r;
-
- /* Converts the specified hostname into DNSSEC canonicalized
- * form. */
-
- if (buffer_max < 2)
- return -ENOBUFS;
-
- for (;;) {
- r = dns_label_unescape(&n, buffer, buffer_max);
- if (r < 0)
- return r;
- if (r == 0)
- break;
-
- if (buffer_max < (size_t) r + 2)
- return -ENOBUFS;
-
- /* The DNSSEC canonical form is not clear on what to
- * do with dots appearing in labels, the way DNS-SD
- * does it. Refuse it for now. */
-
- if (memchr(buffer, '.', r))
- return -EINVAL;
-
- ascii_strlower_n(buffer, (size_t) r);
- buffer[r] = '.';
-
- buffer += r + 1;
- c += r + 1;
-
- buffer_max -= r + 1;
- }
-
- if (c <= 0) {
- /* Not even a single label: this is the root domain name */
-
- assert(buffer_max > 2);
- buffer[0] = '.';
- buffer[1] = 0;
-
- return 1;
- }
-
- return (int) c;
-}
-
-#ifdef HAVE_GCRYPT
-
-static int rr_compare(const void *a, const void *b) {
- DnsResourceRecord **x = (DnsResourceRecord**) a, **y = (DnsResourceRecord**) b;
- size_t m;
- int r;
-
- /* Let's order the RRs according to RFC 4034, Section 6.3 */
-
- assert(x);
- assert(*x);
- assert((*x)->wire_format);
- assert(y);
- assert(*y);
- assert((*y)->wire_format);
-
- m = MIN(DNS_RESOURCE_RECORD_RDATA_SIZE(*x), DNS_RESOURCE_RECORD_RDATA_SIZE(*y));
-
- r = memcmp(DNS_RESOURCE_RECORD_RDATA(*x), DNS_RESOURCE_RECORD_RDATA(*y), m);
- if (r != 0)
- return r;
-
- if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) < DNS_RESOURCE_RECORD_RDATA_SIZE(*y))
- return -1;
- else if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) > DNS_RESOURCE_RECORD_RDATA_SIZE(*y))
- return 1;
-
- return 0;
-}
-
-static int dnssec_rsa_verify_raw(
- const char *hash_algorithm,
- const void *signature, size_t signature_size,
- const void *data, size_t data_size,
- const void *exponent, size_t exponent_size,
- const void *modulus, size_t modulus_size) {
-
- gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL;
- gcry_mpi_t n = NULL, e = NULL, s = NULL;
- gcry_error_t ge;
- int r;
-
- assert(hash_algorithm);
-
- ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature, signature_size, NULL);
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_mpi_scan(&e, GCRYMPI_FMT_USG, exponent, exponent_size, NULL);
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_mpi_scan(&n, GCRYMPI_FMT_USG, modulus, modulus_size, NULL);
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&signature_sexp,
- NULL,
- "(sig-val (rsa (s %m)))",
- s);
-
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&data_sexp,
- NULL,
- "(data (flags pkcs1) (hash %s %b))",
- hash_algorithm,
- (int) data_size,
- data);
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&public_key_sexp,
- NULL,
- "(public-key (rsa (n %m) (e %m)))",
- n,
- e);
- if (ge != 0) {
- r = -EIO;
- goto finish;
- }
-
- ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp);
- if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE)
- r = 0;
- else if (ge != 0) {
- log_debug("RSA signature check failed: %s", gpg_strerror(ge));
- r = -EIO;
- } else
- r = 1;
-
-finish:
- if (e)
- gcry_mpi_release(e);
- if (n)
- gcry_mpi_release(n);
- if (s)
- gcry_mpi_release(s);
-
- if (public_key_sexp)
- gcry_sexp_release(public_key_sexp);
- if (signature_sexp)
- gcry_sexp_release(signature_sexp);
- if (data_sexp)
- gcry_sexp_release(data_sexp);
-
- return r;
-}
-
-static int dnssec_rsa_verify(
- const char *hash_algorithm,
- const void *hash, size_t hash_size,
- DnsResourceRecord *rrsig,
- DnsResourceRecord *dnskey) {
-
- size_t exponent_size, modulus_size;
- void *exponent, *modulus;
-
- assert(hash_algorithm);
- assert(hash);
- assert(hash_size > 0);
- assert(rrsig);
- assert(dnskey);
-
- if (*(uint8_t*) dnskey->dnskey.key == 0) {
- /* exponent is > 255 bytes long */
-
- exponent = (uint8_t*) dnskey->dnskey.key + 3;
- exponent_size =
- ((size_t) (((uint8_t*) dnskey->dnskey.key)[1]) << 8) |
- ((size_t) ((uint8_t*) dnskey->dnskey.key)[2]);
-
- if (exponent_size < 256)
- return -EINVAL;
-
- if (3 + exponent_size >= dnskey->dnskey.key_size)
- return -EINVAL;
-
- modulus = (uint8_t*) dnskey->dnskey.key + 3 + exponent_size;
- modulus_size = dnskey->dnskey.key_size - 3 - exponent_size;
-
- } else {
- /* exponent is <= 255 bytes long */
-
- exponent = (uint8_t*) dnskey->dnskey.key + 1;
- exponent_size = (size_t) ((uint8_t*) dnskey->dnskey.key)[0];
-
- if (exponent_size <= 0)
- return -EINVAL;
-
- if (1 + exponent_size >= dnskey->dnskey.key_size)
- return -EINVAL;
-
- modulus = (uint8_t*) dnskey->dnskey.key + 1 + exponent_size;
- modulus_size = dnskey->dnskey.key_size - 1 - exponent_size;
- }
-
- return dnssec_rsa_verify_raw(
- hash_algorithm,
- rrsig->rrsig.signature, rrsig->rrsig.signature_size,
- hash, hash_size,
- exponent, exponent_size,
- modulus, modulus_size);
-}
-
-static int dnssec_ecdsa_verify_raw(
- const char *hash_algorithm,
- const char *curve,
- const void *signature_r, size_t signature_r_size,
- const void *signature_s, size_t signature_s_size,
- const void *data, size_t data_size,
- const void *key, size_t key_size) {
-
- gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL;
- gcry_mpi_t q = NULL, r = NULL, s = NULL;
- gcry_error_t ge;
- int k;
-
- assert(hash_algorithm);
-
- ge = gcry_mpi_scan(&r, GCRYMPI_FMT_USG, signature_r, signature_r_size, NULL);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature_s, signature_s_size, NULL);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_mpi_scan(&q, GCRYMPI_FMT_USG, key, key_size, NULL);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&signature_sexp,
- NULL,
- "(sig-val (ecdsa (r %m) (s %m)))",
- r,
- s);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&data_sexp,
- NULL,
- "(data (flags rfc6979) (hash %s %b))",
- hash_algorithm,
- (int) data_size,
- data);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_sexp_build(&public_key_sexp,
- NULL,
- "(public-key (ecc (curve %s) (q %m)))",
- curve,
- q);
- if (ge != 0) {
- k = -EIO;
- goto finish;
- }
-
- ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp);
- if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE)
- k = 0;
- else if (ge != 0) {
- log_debug("ECDSA signature check failed: %s", gpg_strerror(ge));
- k = -EIO;
- } else
- k = 1;
-finish:
- if (r)
- gcry_mpi_release(r);
- if (s)
- gcry_mpi_release(s);
- if (q)
- gcry_mpi_release(q);
-
- if (public_key_sexp)
- gcry_sexp_release(public_key_sexp);
- if (signature_sexp)
- gcry_sexp_release(signature_sexp);
- if (data_sexp)
- gcry_sexp_release(data_sexp);
-
- return k;
-}
-
-static int dnssec_ecdsa_verify(
- const char *hash_algorithm,
- int algorithm,
- const void *hash, size_t hash_size,
- DnsResourceRecord *rrsig,
- DnsResourceRecord *dnskey) {
-
- const char *curve;
- size_t key_size;
- uint8_t *q;
-
- assert(hash);
- assert(hash_size);
- assert(rrsig);
- assert(dnskey);
-
- if (algorithm == DNSSEC_ALGORITHM_ECDSAP256SHA256) {
- key_size = 32;
- curve = "NIST P-256";
- } else if (algorithm == DNSSEC_ALGORITHM_ECDSAP384SHA384) {
- key_size = 48;
- curve = "NIST P-384";
- } else
- return -EOPNOTSUPP;
-
- if (dnskey->dnskey.key_size != key_size * 2)
- return -EINVAL;
-
- if (rrsig->rrsig.signature_size != key_size * 2)
- return -EINVAL;
-
- q = alloca(key_size*2 + 1);
- q[0] = 0x04; /* Prepend 0x04 to indicate an uncompressed key */
- memcpy(q+1, dnskey->dnskey.key, key_size*2);
-
- return dnssec_ecdsa_verify_raw(
- hash_algorithm,
- curve,
- rrsig->rrsig.signature, key_size,
- (uint8_t*) rrsig->rrsig.signature + key_size, key_size,
- hash, hash_size,
- q, key_size*2+1);
-}
-
-static void md_add_uint8(gcry_md_hd_t md, uint8_t v) {
- gcry_md_write(md, &v, sizeof(v));
-}
-
-static void md_add_uint16(gcry_md_hd_t md, uint16_t v) {
- v = htobe16(v);
- gcry_md_write(md, &v, sizeof(v));
-}
-
-static void md_add_uint32(gcry_md_hd_t md, uint32_t v) {
- v = htobe32(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;
-
- assert(rrsig);
- assert(rrsig->key->type == DNS_TYPE_RRSIG);
-
- if (realtime == USEC_INFINITY)
- realtime = now(CLOCK_REALTIME);
-
- expiration = rrsig->rrsig.expiration * USEC_PER_SEC;
- inception = rrsig->rrsig.inception * USEC_PER_SEC;
-
- /* Consider inverted validity intervals as expired */
- if (inception > expiration)
- return true;
-
- /* Permit a certain amount of clock skew of 10% of the valid
- * time range. This takes inspiration from unbound's
- * resolver. */
- skew = (expiration - inception) / 10;
- if (skew > SKEW_MAX)
- skew = SKEW_MAX;
-
- if (inception < skew)
- inception = 0;
- else
- inception -= skew;
-
- if (expiration + skew < expiration)
- expiration = USEC_INFINITY;
- else
- expiration += skew;
-
- return realtime < inception || realtime > expiration;
-}
-
-static int algorithm_to_gcrypt_md(uint8_t algorithm) {
-
- /* Translates a DNSSEC signature algorithm into a gcrypt
- * digest identifier.
- *
- * Note that we implement all algorithms listed as "Must
- * implement" and "Recommended to Implement" in RFC6944. We
- * don't implement any algorithms that are listed as
- * "Optional" or "Must Not Implement". Specifically, we do not
- * implement RSAMD5, DSASHA1, DH, DSA-NSEC3-SHA1, and
- * GOST-ECC. */
-
- switch (algorithm) {
-
- case DNSSEC_ALGORITHM_RSASHA1:
- case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1:
- return GCRY_MD_SHA1;
-
- case DNSSEC_ALGORITHM_RSASHA256:
- case DNSSEC_ALGORITHM_ECDSAP256SHA256:
- return GCRY_MD_SHA256;
-
- case DNSSEC_ALGORITHM_ECDSAP384SHA384:
- return GCRY_MD_SHA384;
-
- case DNSSEC_ALGORITHM_RSASHA512:
- return GCRY_MD_SHA512;
-
- default:
- return -EOPNOTSUPP;
- }
-}
-
-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,
- DnsResourceRecord *rrsig,
- DnsResourceRecord *dnskey,
- usec_t realtime,
- DnssecResult *result) {
-
- uint8_t wire_format_name[DNS_WIRE_FOMAT_HOSTNAME_MAX];
- DnsResourceRecord **list, *rr;
- const char *source, *name;
- gcry_md_hd_t md = NULL;
- int r, md_algorithm;
- size_t k, n = 0;
- size_t hash_size;
- void *hash;
- bool wildcard;
-
- assert(key);
- assert(rrsig);
- assert(dnskey);
- assert(result);
- assert(rrsig->key->type == DNS_TYPE_RRSIG);
- assert(dnskey->key->type == DNS_TYPE_DNSKEY);
-
- /* Verifies that the RRSet matches the specified "key" in "a",
- * using the signature "rrsig" and the key "dnskey". It's
- * assumed that RRSIG and DNSKEY match. */
-
- md_algorithm = algorithm_to_gcrypt_md(rrsig->rrsig.algorithm);
- if (md_algorithm == -EOPNOTSUPP) {
- *result = DNSSEC_UNSUPPORTED_ALGORITHM;
- return 0;
- }
- 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;
- if (r > 0) {
- *result = DNSSEC_SIGNATURE_EXPIRED;
- return 0;
- }
-
- name = dns_resource_key_name(key);
-
- /* Some keys may only appear signed in the zone apex, and are invalid anywhere else. (SOA, NS...) */
- if (dns_type_apex_only(rrsig->rrsig.type_covered)) {
- r = dns_name_equal(rrsig->rrsig.signer, name);
- if (r < 0)
- return r;
- if (r == 0) {
- *result = DNSSEC_INVALID;
- return 0;
- }
- }
-
- /* OTOH DS RRs may not appear in the zone apex, but are valid everywhere else. */
- if (rrsig->rrsig.type_covered == DNS_TYPE_DS) {
- r = dns_name_equal(rrsig->rrsig.signer, name);
- if (r < 0)
- return r;
- if (r > 0) {
- *result = DNSSEC_INVALID;
- return 0;
- }
- }
-
- /* Determine the "Source of Synthesis" and whether this is a wildcard RRSIG */
- r = dns_name_suffix(name, rrsig->rrsig.labels, &source);
- if (r < 0)
- return r;
- if (r > 0 && !dns_type_may_wildcard(rrsig->rrsig.type_covered)) {
- /* We refuse to validate NSEC3 or SOA RRs that are synthesized from wildcards */
- *result = DNSSEC_INVALID;
- return 0;
- }
- if (r == 1) {
- /* If we stripped a single label, then let's see if that maybe was "*". If so, we are not really
- * synthesized from a wildcard, we are the wildcard itself. Treat that like a normal name. */
- r = dns_name_startswith(name, "*");
- if (r < 0)
- return r;
- if (r > 0)
- source = name;
-
- wildcard = r == 0;
- } else
- wildcard = r > 0;
-
- /* Collect all relevant RRs in a single array, so that we can look at the RRset */
- list = newa(DnsResourceRecord *, dns_answer_size(a));
-
- DNS_ANSWER_FOREACH(rr, a) {
- r = dns_resource_key_equal(key, rr->key);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- /* We need the wire format for ordering, and digest calculation */
- r = dns_resource_record_to_wire_format(rr, true);
- if (r < 0)
- return r;
-
- list[n++] = rr;
-
- if (n > VERIFY_RRS_MAX)
- return -E2BIG;
- }
-
- if (n <= 0)
- return -ENODATA;
-
- /* Bring the RRs into canonical order */
- qsort_safe(list, n, sizeof(DnsResourceRecord*), rr_compare);
-
- /* OK, the RRs are now in canonical order. Let's calculate the digest */
- initialize_libgcrypt(false);
-
- hash_size = gcry_md_get_algo_dlen(md_algorithm);
- assert(hash_size > 0);
-
- gcry_md_open(&md, md_algorithm, 0);
- if (!md)
- return -EIO;
-
- md_add_uint16(md, rrsig->rrsig.type_covered);
- md_add_uint8(md, rrsig->rrsig.algorithm);
- md_add_uint8(md, rrsig->rrsig.labels);
- md_add_uint32(md, rrsig->rrsig.original_ttl);
- md_add_uint32(md, rrsig->rrsig.expiration);
- md_add_uint32(md, rrsig->rrsig.inception);
- md_add_uint16(md, rrsig->rrsig.key_tag);
-
- r = dns_name_to_wire_format(rrsig->rrsig.signer, wire_format_name, sizeof(wire_format_name), true);
- if (r < 0)
- goto finish;
- gcry_md_write(md, wire_format_name, r);
-
- /* Convert the source of synthesis into wire format */
- r = dns_name_to_wire_format(source, wire_format_name, sizeof(wire_format_name), true);
- if (r < 0)
- goto finish;
-
- for (k = 0; k < n; k++) {
- size_t l;
-
- rr = list[k];
-
- /* Hash the source of synthesis. If this is a wildcard, then prefix it with the *. label */
- if (wildcard)
- gcry_md_write(md, (uint8_t[]) { 1, '*'}, 2);
- gcry_md_write(md, wire_format_name, r);
-
- md_add_uint16(md, rr->key->type);
- md_add_uint16(md, rr->key->class);
- md_add_uint32(md, rrsig->rrsig.original_ttl);
-
- l = DNS_RESOURCE_RECORD_RDATA_SIZE(rr);
- assert(l <= 0xFFFF);
-
- md_add_uint16(md, (uint16_t) l);
- gcry_md_write(md, DNS_RESOURCE_RECORD_RDATA(rr), l);
- }
-
- hash = gcry_md_read(md, 0);
- if (!hash) {
- r = -EIO;
- goto finish;
- }
-
- switch (rrsig->rrsig.algorithm) {
-
- case DNSSEC_ALGORITHM_RSASHA1:
- case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1:
- case DNSSEC_ALGORITHM_RSASHA256:
- case DNSSEC_ALGORITHM_RSASHA512:
- r = dnssec_rsa_verify(
- gcry_md_algo_name(md_algorithm),
- hash, hash_size,
- rrsig,
- dnskey);
- break;
-
- case DNSSEC_ALGORITHM_ECDSAP256SHA256:
- case DNSSEC_ALGORITHM_ECDSAP384SHA384:
- r = dnssec_ecdsa_verify(
- gcry_md_algo_name(md_algorithm),
- rrsig->rrsig.algorithm,
- hash, hash_size,
- rrsig,
- dnskey);
- break;
- }
-
- if (r < 0)
- goto finish;
-
- /* 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:
- gcry_md_close(md);
- return r;
-}
-
-int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) {
-
- assert(rrsig);
- assert(dnskey);
-
- /* Checks if the specified DNSKEY RR matches the key used for
- * the signature in the specified RRSIG RR */
-
- if (rrsig->key->type != DNS_TYPE_RRSIG)
- return -EINVAL;
-
- if (dnskey->key->type != DNS_TYPE_DNSKEY)
- return 0;
- if (dnskey->key->class != rrsig->key->class)
- return 0;
- if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0)
- return 0;
- if (!revoked_ok && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE))
- return 0;
- if (dnskey->dnskey.protocol != 3)
- return 0;
- if (dnskey->dnskey.algorithm != rrsig->rrsig.algorithm)
- return 0;
-
- if (dnssec_keytag(dnskey, false) != rrsig->rrsig.key_tag)
- return 0;
-
- return dns_name_equal(dns_resource_key_name(dnskey->key), rrsig->rrsig.signer);
-}
-
-int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) {
- assert(key);
- assert(rrsig);
-
- /* Checks if the specified RRSIG RR protects the RRSet of the specified RR key. */
-
- if (rrsig->key->type != DNS_TYPE_RRSIG)
- return 0;
- if (rrsig->key->class != key->class)
- return 0;
- if (rrsig->rrsig.type_covered != key->type)
- return 0;
-
- return dns_name_equal(dns_resource_key_name(rrsig->key), dns_resource_key_name(key));
-}
-
-int dnssec_verify_rrset_search(
- DnsAnswer *a,
- const DnsResourceKey *key,
- DnsAnswer *validated_dnskeys,
- usec_t realtime,
- DnssecResult *result,
- DnsResourceRecord **ret_rrsig) {
-
- bool found_rrsig = false, found_invalid = false, found_expired_rrsig = false, found_unsupported_algorithm = false;
- DnsResourceRecord *rrsig;
- int r;
-
- assert(key);
- assert(result);
-
- /* Verifies all RRs from "a" that match the key "key" against DNSKEYs in "validated_dnskeys" */
-
- if (!a || a->n_rrs <= 0)
- return -ENODATA;
-
- /* 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);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- found_rrsig = true;
-
- /* Look for a matching key */
- 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, false);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- /* Take the time here, if it isn't set yet, so
- * that we do all validations with the same
- * time. */
- if (realtime == USEC_INFINITY)
- realtime = now(CLOCK_REALTIME);
-
- /* Yay, we found a matching RRSIG with a matching
- * DNSKEY, awesome. Now let's verify all entries of
- * the RRSet against the RRSIG and DNSKEY
- * combination. */
-
- r = dnssec_verify_rrset(a, key, rrsig, dnskey, realtime, &one_result);
- if (r < 0)
- return r;
-
- switch (one_result) {
-
- case DNSSEC_VALIDATED:
- case DNSSEC_VALIDATED_WILDCARD:
- /* Yay, the RR has been validated,
- * return immediately, but fix up the expiry */
- if (ret_rrsig)
- *ret_rrsig = rrsig;
-
- *result = one_result;
- return 0;
-
- case DNSSEC_INVALID:
- /* If the signature is invalid, let's try another
- key and/or signature. After all they
- key_tags and stuff are not unique, and
- might be shared by multiple keys. */
- found_invalid = true;
- continue;
-
- case DNSSEC_UNSUPPORTED_ALGORITHM:
- /* If the key algorithm is
- unsupported, try another
- RRSIG/DNSKEY pair, but remember we
- encountered this, so that we can
- return a proper error when we
- encounter nothing better. */
- found_unsupported_algorithm = true;
- continue;
-
- case DNSSEC_SIGNATURE_EXPIRED:
- /* If the signature is expired, try
- another one, but remember it, so
- that we can return this */
- found_expired_rrsig = true;
- continue;
-
- default:
- assert_not_reached("Unexpected DNSSEC validation result");
- }
- }
- }
-
- if (found_expired_rrsig)
- *result = DNSSEC_SIGNATURE_EXPIRED;
- else if (found_unsupported_algorithm)
- *result = DNSSEC_UNSUPPORTED_ALGORITHM;
- else if (found_invalid)
- *result = DNSSEC_INVALID;
- else if (found_rrsig)
- *result = DNSSEC_MISSING_KEY;
- else
- *result = DNSSEC_NO_SIGNATURE;
-
- if (ret_rrsig)
- *ret_rrsig = NULL;
-
- 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;
-}
-
-static int digest_to_gcrypt_md(uint8_t algorithm) {
-
- /* Translates a DNSSEC digest algorithm into a gcrypt digest identifier */
-
- switch (algorithm) {
-
- case DNSSEC_DIGEST_SHA1:
- return GCRY_MD_SHA1;
-
- case DNSSEC_DIGEST_SHA256:
- return GCRY_MD_SHA256;
-
- case DNSSEC_DIGEST_SHA384:
- return GCRY_MD_SHA384;
-
- default:
- return -EOPNOTSUPP;
- }
-}
-
-int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) {
- char owner_name[DNSSEC_CANONICAL_HOSTNAME_MAX];
- gcry_md_hd_t md = NULL;
- size_t hash_size;
- int md_algorithm, r;
- void *result;
-
- assert(dnskey);
- assert(ds);
-
- /* Implements DNSKEY verification by a DS, according to RFC 4035, section 5.2 */
-
- if (dnskey->key->type != DNS_TYPE_DNSKEY)
- return -EINVAL;
- if (ds->key->type != DNS_TYPE_DS)
- return -EINVAL;
- if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0)
- return -EKEYREJECTED;
- if (!mask_revoke && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE))
- return -EKEYREJECTED;
- if (dnskey->dnskey.protocol != 3)
- return -EKEYREJECTED;
-
- if (dnskey->dnskey.algorithm != ds->ds.algorithm)
- return 0;
- if (dnssec_keytag(dnskey, mask_revoke) != ds->ds.key_tag)
- return 0;
-
- initialize_libgcrypt(false);
-
- md_algorithm = digest_to_gcrypt_md(ds->ds.digest_type);
- if (md_algorithm < 0)
- return md_algorithm;
-
- hash_size = gcry_md_get_algo_dlen(md_algorithm);
- assert(hash_size > 0);
-
- if (ds->ds.digest_size != hash_size)
- return 0;
-
- r = dnssec_canonicalize(dns_resource_key_name(dnskey->key), owner_name, sizeof(owner_name));
- if (r < 0)
- return r;
-
- gcry_md_open(&md, md_algorithm, 0);
- if (!md)
- return -EIO;
-
- gcry_md_write(md, owner_name, r);
- if (mask_revoke)
- md_add_uint16(md, dnskey->dnskey.flags & ~DNSKEY_FLAG_REVOKE);
- else
- md_add_uint16(md, dnskey->dnskey.flags);
- md_add_uint8(md, dnskey->dnskey.protocol);
- md_add_uint8(md, dnskey->dnskey.algorithm);
- gcry_md_write(md, dnskey->dnskey.key, dnskey->dnskey.key_size);
-
- result = gcry_md_read(md, 0);
- if (!result) {
- r = -EIO;
- goto finish;
- }
-
- r = memcmp(result, ds->ds.digest, ds->ds.digest_size) != 0;
-
-finish:
- gcry_md_close(md);
- return r;
-}
-
-int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) {
- DnsResourceRecord *ds;
- DnsAnswerFlags flags;
- int r;
-
- assert(dnskey);
-
- if (dnskey->key->type != DNS_TYPE_DNSKEY)
- return 0;
-
- DNS_ANSWER_FOREACH_FLAGS(ds, flags, validated_ds) {
-
- if ((flags & DNS_ANSWER_AUTHENTICATED) == 0)
- continue;
-
- if (ds->key->type != DNS_TYPE_DS)
- continue;
- if (ds->key->class != dnskey->key->class)
- continue;
-
- r = dns_name_equal(dns_resource_key_name(dnskey->key), dns_resource_key_name(ds->key));
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- r = dnssec_verify_dnskey_by_ds(dnskey, ds, false);
- if (IN_SET(r, -EKEYREJECTED, -EOPNOTSUPP))
- return 0; /* The DNSKEY is revoked or otherwise invalid, or we don't support the digest algorithm */
- if (r < 0)
- return r;
- if (r > 0)
- return 1;
- }
-
- return 0;
-}
-
-static int nsec3_hash_to_gcrypt_md(uint8_t algorithm) {
-
- /* Translates a DNSSEC NSEC3 hash algorithm into a gcrypt digest identifier */
-
- switch (algorithm) {
-
- case NSEC3_ALGORITHM_SHA1:
- return GCRY_MD_SHA1;
-
- default:
- return -EOPNOTSUPP;
- }
-}
-
-int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) {
- uint8_t wire_format[DNS_WIRE_FOMAT_HOSTNAME_MAX];
- gcry_md_hd_t md = NULL;
- size_t hash_size;
- int algorithm;
- void *result;
- unsigned k;
- int r;
-
- assert(nsec3);
- assert(name);
- assert(ret);
-
- if (nsec3->key->type != DNS_TYPE_NSEC3)
- return -EINVAL;
-
- if (nsec3->nsec3.iterations > NSEC3_ITERATIONS_MAX) {
- log_debug("Ignoring NSEC3 RR %s with excessive number of iterations.", dns_resource_record_to_string(nsec3));
- return -EOPNOTSUPP;
- }
-
- algorithm = nsec3_hash_to_gcrypt_md(nsec3->nsec3.algorithm);
- if (algorithm < 0)
- return algorithm;
-
- initialize_libgcrypt(false);
-
- hash_size = gcry_md_get_algo_dlen(algorithm);
- assert(hash_size > 0);
-
- if (nsec3->nsec3.next_hashed_name_size != hash_size)
- return -EINVAL;
-
- r = dns_name_to_wire_format(name, wire_format, sizeof(wire_format), true);
- if (r < 0)
- return r;
-
- gcry_md_open(&md, algorithm, 0);
- if (!md)
- return -EIO;
-
- gcry_md_write(md, wire_format, r);
- gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size);
-
- result = gcry_md_read(md, 0);
- if (!result) {
- r = -EIO;
- goto finish;
- }
-
- for (k = 0; k < nsec3->nsec3.iterations; k++) {
- uint8_t tmp[hash_size];
- memcpy(tmp, result, hash_size);
-
- gcry_md_reset(md);
- gcry_md_write(md, tmp, hash_size);
- gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size);
-
- result = gcry_md_read(md, 0);
- if (!result) {
- r = -EIO;
- goto finish;
- }
- }
-
- memcpy(ret, result, hash_size);
- r = (int) hash_size;
-
-finish:
- gcry_md_close(md);
- return r;
-}
-
-static int nsec3_is_good(DnsResourceRecord *rr, DnsResourceRecord *nsec3) {
- const char *a, *b;
- int r;
-
- assert(rr);
-
- if (rr->key->type != DNS_TYPE_NSEC3)
- 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))
- return 0;
-
- /* Ignore NSEC3 RRs whose algorithm we don't know */
- if (nsec3_hash_to_gcrypt_md(rr->nsec3.algorithm) < 0)
- return 0;
- /* Ignore NSEC3 RRs with an excessive number of required iterations */
- if (rr->nsec3.iterations > NSEC3_ITERATIONS_MAX)
- return 0;
-
- /* Ignore NSEC3 RRs generated from wildcards. If these NSEC3 RRs weren't correctly signed we can't make this
- * check (since rr->n_skip_labels_source is -1), but that's OK, as we won't trust them anyway in that case. */
- if (rr->n_skip_labels_source != 0 && rr->n_skip_labels_source != (unsigned) -1)
- return 0;
- /* Ignore NSEC3 RRs that are located anywhere else than one label below the zone */
- if (rr->n_skip_labels_signer != 1 && rr->n_skip_labels_signer != (unsigned) -1)
- return 0;
-
- if (!nsec3)
- return 1;
-
- /* If a second NSEC3 RR is specified, also check if they are from the same zone. */
-
- if (nsec3 == rr) /* Shortcut */
- return 1;
-
- if (rr->key->class != nsec3->key->class)
- return 0;
- if (rr->nsec3.algorithm != nsec3->nsec3.algorithm)
- return 0;
- if (rr->nsec3.iterations != nsec3->nsec3.iterations)
- return 0;
- if (rr->nsec3.salt_size != nsec3->nsec3.salt_size)
- return 0;
- if (memcmp(rr->nsec3.salt, nsec3->nsec3.salt, rr->nsec3.salt_size) != 0)
- return 0;
-
- a = dns_resource_key_name(rr->key);
- r = dns_name_parent(&a); /* strip off hash */
- if (r < 0)
- return r;
- if (r == 0)
- return 0;
-
- b = dns_resource_key_name(nsec3->key);
- r = dns_name_parent(&b); /* strip off hash */
- if (r < 0)
- return r;
- if (r == 0)
- return 0;
-
- /* Make sure both have the same parent */
- return dns_name_equal(a, b);
-}
-
-static int nsec3_hashed_domain_format(const uint8_t *hashed, size_t hashed_size, const char *zone, char **ret) {
- _cleanup_free_ char *l = NULL;
- char *j;
-
- assert(hashed);
- assert(hashed_size > 0);
- assert(zone);
- assert(ret);
-
- l = base32hexmem(hashed, hashed_size, false);
- if (!l)
- return -ENOMEM;
-
- j = strjoin(l, ".", zone, NULL);
- if (!j)
- return -ENOMEM;
-
- *ret = j;
- return (int) hashed_size;
-}
-
-static int nsec3_hashed_domain_make(DnsResourceRecord *nsec3, const char *domain, const char *zone, char **ret) {
- uint8_t hashed[DNSSEC_HASH_SIZE_MAX];
- int hashed_size;
-
- assert(nsec3);
- assert(domain);
- assert(zone);
- assert(ret);
-
- hashed_size = dnssec_nsec3_hash(nsec3, domain, hashed);
- if (hashed_size < 0)
- return hashed_size;
-
- return nsec3_hashed_domain_format(hashed, (size_t) hashed_size, zone, ret);
-}
-
-/* See RFC 5155, Section 8
- * First try to find a NSEC3 record that matches our query precisely, if that fails, find the closest
- * enclosure. Secondly, find a proof that there is no closer enclosure and either a proof that there
- * is no wildcard domain as a direct descendant of the closest enclosure, or find an NSEC3 record that
- * matches the wildcard domain.
- *
- * Based on this we can prove either the existence of the record in @key, or NXDOMAIN or NODATA, or
- * that there is no proof either way. The latter is the case if a the proof of non-existence of a given
- * name uses an NSEC3 record with the opt-out bit set. Lastly, if we are given insufficient NSEC3 records
- * to conclude anything we indicate this by returning NO_RR. */
-static int dnssec_test_nsec3(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) {
- _cleanup_free_ char *next_closer_domain = NULL, *wildcard_domain = NULL;
- const char *zone, *p, *pp = NULL, *wildcard;
- DnsResourceRecord *rr, *enclosure_rr, *zone_rr, *wildcard_rr = NULL;
- DnsAnswerFlags flags;
- int hashed_size, r;
- bool a, no_closer = false, no_wildcard = false, optout = false;
-
- assert(key);
- assert(result);
-
- /* First step, find the zone name and the NSEC3 parameters of the zone.
- * it is sufficient to look for the longest common suffix we find with
- * any NSEC3 RR in the response. Any NSEC3 record will do as all NSEC3
- * records from a given zone in a response must use the same
- * parameters. */
- zone = dns_resource_key_name(key);
- for (;;) {
- DNS_ANSWER_FOREACH_FLAGS(zone_rr, flags, answer) {
- r = nsec3_is_good(zone_rr, NULL);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- r = dns_name_equal_skip(dns_resource_key_name(zone_rr->key), 1, zone);
- if (r < 0)
- return r;
- if (r > 0)
- goto found_zone;
- }
-
- /* Strip one label from the front */
- r = dns_name_parent(&zone);
- if (r < 0)
- return r;
- if (r == 0)
- break;
- }
-
- *result = DNSSEC_NSEC_NO_RR;
- return 0;
-
-found_zone:
- /* Second step, find the closest encloser NSEC3 RR in 'answer' that matches 'key' */
- p = dns_resource_key_name(key);
- for (;;) {
- _cleanup_free_ char *hashed_domain = NULL;
-
- hashed_size = nsec3_hashed_domain_make(zone_rr, p, zone, &hashed_domain);
- if (hashed_size == -EOPNOTSUPP) {
- *result = DNSSEC_NSEC_UNSUPPORTED_ALGORITHM;
- return 0;
- }
- if (hashed_size < 0)
- return hashed_size;
-
- DNS_ANSWER_FOREACH_FLAGS(enclosure_rr, flags, answer) {
-
- r = nsec3_is_good(enclosure_rr, zone_rr);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- if (enclosure_rr->nsec3.next_hashed_name_size != (size_t) hashed_size)
- continue;
-
- r = dns_name_equal(dns_resource_key_name(enclosure_rr->key), hashed_domain);
- if (r < 0)
- return r;
- if (r > 0) {
- a = flags & DNS_ANSWER_AUTHENTICATED;
- goto found_closest_encloser;
- }
- }
-
- /* 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;
- }
-
- *result = DNSSEC_NSEC_NO_RR;
- return 0;
-
-found_closest_encloser:
- /* We found a closest encloser in 'p'; next closer is 'pp' */
-
- if (!pp) {
- /* We have an exact match! If we area looking for a DS RR, then we must insist that we got the NSEC3 RR
- * from the parent. Otherwise the one from the child. Do so, by checking whether SOA and NS are
- * appropriately set. */
-
- if (key->type == DNS_TYPE_DS) {
- if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA))
- return -EBADMSG;
- } else {
- if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_NS) &&
- !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA))
- return -EBADMSG;
- }
-
- /* No next closer NSEC3 RR. That means there's a direct NSEC3 RR for our key. */
- if (bitmap_isset(enclosure_rr->nsec3.types, key->type))
- *result = DNSSEC_NSEC_FOUND;
- else if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_CNAME))
- *result = DNSSEC_NSEC_CNAME;
- else
- *result = DNSSEC_NSEC_NODATA;
-
- if (authenticated)
- *authenticated = a;
- if (ttl)
- *ttl = enclosure_rr->ttl;
-
- return 0;
- }
-
- /* Ensure this is not a DNAME domain, see RFC5155, section 8.3. */
- if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_DNAME))
- return -EBADMSG;
-
- /* 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(enclosure_rr->nsec3.types, DNS_TYPE_NS) &&
- !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA))
- return -EBADMSG;
-
- /* Prove that there is no next closer and whether or not there is a wildcard domain. */
-
- wildcard = strjoina("*.", p);
- r = nsec3_hashed_domain_make(enclosure_rr, wildcard, zone, &wildcard_domain);
- if (r < 0)
- return r;
- if (r != hashed_size)
- return -EBADMSG;
-
- r = nsec3_hashed_domain_make(enclosure_rr, pp, zone, &next_closer_domain);
- if (r < 0)
- return r;
- if (r != hashed_size)
- return -EBADMSG;
-
- DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
- _cleanup_free_ char *next_hashed_domain = NULL;
-
- r = nsec3_is_good(rr, zone_rr);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- 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), next_closer_domain, next_hashed_domain);
- if (r < 0)
- return r;
- if (r > 0) {
- if (rr->nsec3.flags & 1)
- optout = true;
-
- a = a && (flags & DNS_ANSWER_AUTHENTICATED);
-
- no_closer = true;
- }
-
- r = dns_name_equal(dns_resource_key_name(rr->key), wildcard_domain);
- if (r < 0)
- return r;
- if (r > 0) {
- a = a && (flags & DNS_ANSWER_AUTHENTICATED);
-
- wildcard_rr = rr;
- }
-
- r = dns_name_between(dns_resource_key_name(rr->key), wildcard_domain, next_hashed_domain);
- if (r < 0)
- return r;
- if (r > 0) {
- if (rr->nsec3.flags & 1)
- /* This only makes sense if we have a wildcard delegation, which is
- * very unlikely, see RFC 4592, Section 4.2, but we cannot rely on
- * this not happening, so hence cannot simply conclude NXDOMAIN as
- * we would wish */
- optout = true;
-
- a = a && (flags & DNS_ANSWER_AUTHENTICATED);
-
- no_wildcard = true;
- }
- }
-
- if (wildcard_rr && no_wildcard)
- return -EBADMSG;
-
- if (!no_closer) {
- *result = DNSSEC_NSEC_NO_RR;
- return 0;
- }
-
- if (wildcard_rr) {
- /* A wildcard exists that matches our query. */
- if (optout)
- /* This is not specified in any RFC to the best of my knowledge, but
- * if the next closer enclosure is covered by an opt-out NSEC3 RR
- * it means that we cannot prove that the source of synthesis is
- * correct, as there may be a closer match. */
- *result = DNSSEC_NSEC_OPTOUT;
- else if (bitmap_isset(wildcard_rr->nsec3.types, key->type))
- *result = DNSSEC_NSEC_FOUND;
- else if (bitmap_isset(wildcard_rr->nsec3.types, DNS_TYPE_CNAME))
- *result = DNSSEC_NSEC_CNAME;
- else
- *result = DNSSEC_NSEC_NODATA;
- } else {
- if (optout)
- /* The RFC only specifies that we have to care for optout for NODATA for
- * DS records. However, children of an insecure opt-out delegation should
- * also be considered opt-out, rather than verified NXDOMAIN.
- * Note that we do not require a proof of wildcard non-existence if the
- * next closer domain is covered by an opt-out, as that would not provide
- * any additional information. */
- *result = DNSSEC_NSEC_OPTOUT;
- else if (no_wildcard)
- *result = DNSSEC_NSEC_NXDOMAIN;
- else {
- *result = DNSSEC_NSEC_NO_RR;
-
- return 0;
- }
- }
-
- if (authenticated)
- *authenticated = a;
-
- if (ttl)
- *ttl = enclosure_rr->ttl;
-
- return 0;
-}
-
-static int dnssec_nsec_wildcard_equal(DnsResourceRecord *rr, const char *name) {
- char label[DNS_LABEL_MAX];
- const char *n;
- int r;
-
- assert(rr);
- assert(rr->key->type == DNS_TYPE_NSEC);
-
- /* Checks whether the specified RR has a name beginning in "*.", and if the rest is a suffix of our name */
-
- if (rr->n_skip_labels_source != 1)
- return 0;
-
- n = dns_resource_key_name(rr->key);
- r = dns_label_unescape(&n, label, sizeof(label));
- if (r <= 0)
- return r;
- if (r != 1 || label[0] != '*')
- return 0;
-
- return dns_name_endswith(name, n);
-}
-
-static int dnssec_nsec_in_path(DnsResourceRecord *rr, const char *name) {
- const char *nn, *common_suffix;
- int r;
-
- assert(rr);
- assert(rr->key->type == DNS_TYPE_NSEC);
-
- /* Checks whether the specified nsec RR indicates that name is an empty non-terminal (ENT)
- *
- * A couple of examples:
- *
- * NSEC bar → waldo.foo.bar: indicates that foo.bar exists and is an ENT
- * NSEC waldo.foo.bar → yyy.zzz.xoo.bar: indicates that xoo.bar and zzz.xoo.bar exist and are ENTs
- * NSEC yyy.zzz.xoo.bar → bar: indicates pretty much nothing about ENTs
- */
-
- /* First, determine parent of next domain. */
- nn = rr->nsec.next_domain_name;
- r = dns_name_parent(&nn);
- if (r <= 0)
- return r;
-
- /* If the name we just determined is not equal or child of the name we are interested in, then we can't say
- * anything at all. */
- r = dns_name_endswith(nn, name);
- if (r <= 0)
- return r;
-
- /* If the name we are interested in is not a prefix of the common suffix of the NSEC RR's owner and next domain names, then we can't say anything either. */
- r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix);
- if (r < 0)
- return r;
-
- return dns_name_endswith(name, common_suffix);
-}
-
-static int dnssec_nsec_from_parent_zone(DnsResourceRecord *rr, const char *name) {
- int r;
-
- assert(rr);
- assert(rr->key->type == DNS_TYPE_NSEC);
-
- /* Checks whether this NSEC originates to the parent zone or the child zone. */
-
- r = dns_name_parent(&name);
- if (r <= 0)
- return r;
-
- r = dns_name_equal(name, dns_resource_key_name(rr->key));
- if (r <= 0)
- return r;
-
- /* DNAME, and NS without SOA is an indication for a delegation. */
- if (bitmap_isset(rr->nsec.types, DNS_TYPE_DNAME))
- return 1;
-
- if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) && !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA))
- return 1;
-
- return 0;
-}
-
-static int dnssec_nsec_covers(DnsResourceRecord *rr, const char *name) {
- const char *common_suffix, *p;
- int r;
-
- assert(rr);
- assert(rr->key->type == DNS_TYPE_NSEC);
-
- /* Checks whether the "Next Closer" is witin the space covered by the specified RR. */
-
- r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix);
- if (r < 0)
- return r;
-
- for (;;) {
- p = name;
- r = dns_name_parent(&name);
- if (r < 0)
- return r;
- if (r == 0)
- return 0;
-
- r = dns_name_equal(name, common_suffix);
- if (r < 0)
- return r;
- if (r > 0)
- break;
- }
-
- /* p is now the "Next Closer". */
-
- return dns_name_between(dns_resource_key_name(rr->key), p, rr->nsec.next_domain_name);
-}
-
-static int dnssec_nsec_covers_wildcard(DnsResourceRecord *rr, const char *name) {
- const char *common_suffix, *wc;
- int r;
-
- assert(rr);
- assert(rr->key->type == DNS_TYPE_NSEC);
-
- /* Checks whether the "Wildcard at the Closest Encloser" is within the space covered by the specified
- * RR. Specifically, checks whether 'name' has the common suffix of the NSEC RR's owner and next names as
- * suffix, and whether the NSEC covers the name generated by that suffix prepended with an asterisk label.
- *
- * NSEC bar → waldo.foo.bar: indicates that *.bar and *.foo.bar do not exist
- * NSEC waldo.foo.bar → yyy.zzz.xoo.bar: indicates that *.xoo.bar and *.zzz.xoo.bar do not exist (and more ...)
- * NSEC yyy.zzz.xoo.bar → bar: indicates that a number of wildcards don#t exist either...
- */
-
- r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix);
- if (r < 0)
- return r;
-
- /* If the common suffix is not shared by the name we are interested in, it has nothing to say for us. */
- r = dns_name_endswith(name, common_suffix);
- if (r <= 0)
- return r;
-
- wc = strjoina("*.", common_suffix);
- return dns_name_between(dns_resource_key_name(rr->key), wc, rr->nsec.next_domain_name);
-}
-
-int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) {
- bool have_nsec3 = false, covering_rr_authenticated = false, wildcard_rr_authenticated = false;
- DnsResourceRecord *rr, *covering_rr = NULL, *wildcard_rr = NULL;
- DnsAnswerFlags flags;
- const char *name;
- int r;
-
- assert(key);
- assert(result);
-
- /* Look for any NSEC/NSEC3 RRs that say something about the specified key. */
-
- name = dns_resource_key_name(key);
-
- DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) {
-
- if (rr->key->class != key->class)
- continue;
-
- have_nsec3 = have_nsec3 || (rr->key->type == DNS_TYPE_NSEC3);
-
- if (rr->key->type != DNS_TYPE_NSEC)
- continue;
-
- /* The following checks only make sense for NSEC RRs that are not expanded from a wildcard */
- r = dns_resource_record_is_synthetic(rr);
- if (r < 0)
- return r;
- if (r > 0)
- continue;
-
- /* Check if this is a direct match. If so, we have encountered a NODATA case */
- r = dns_name_equal(dns_resource_key_name(rr->key), name);
- if (r < 0)
- return r;
- if (r == 0) {
- /* If it's not a direct match, maybe it's a wild card match? */
- r = dnssec_nsec_wildcard_equal(rr, name);
- if (r < 0)
- return r;
- }
- if (r > 0) {
- if (key->type == DNS_TYPE_DS) {
- /* If we look for a DS RR and the server sent us the NSEC RR of the child zone
- * we have a problem. For DS RRs we want the NSEC RR from the parent */
- if (bitmap_isset(rr->nsec.types, DNS_TYPE_SOA))
- continue;
- } else {
- /* For all RR types, ensure that if NS is set SOA is set too, so that we know
- * we got the child's NSEC. */
- if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) &&
- !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA))
- continue;
- }
-
- if (bitmap_isset(rr->nsec.types, key->type))
- *result = DNSSEC_NSEC_FOUND;
- else if (bitmap_isset(rr->nsec.types, DNS_TYPE_CNAME))
- *result = DNSSEC_NSEC_CNAME;
- else
- *result = DNSSEC_NSEC_NODATA;
-
- if (authenticated)
- *authenticated = flags & DNS_ANSWER_AUTHENTICATED;
- if (ttl)
- *ttl = rr->ttl;
-
- return 0;
- }
-
- /* Check if the name we are looking for is an empty non-terminal within the owner or next name
- * of the NSEC RR. */
- r = dnssec_nsec_in_path(rr, name);
- if (r < 0)
- return r;
- if (r > 0) {
- *result = DNSSEC_NSEC_NODATA;
-
- if (authenticated)
- *authenticated = flags & DNS_ANSWER_AUTHENTICATED;
- if (ttl)
- *ttl = rr->ttl;
-
- return 0;
- }
-
- /* The following two "covering" checks, are not useful if the NSEC is from the parent */
- r = dnssec_nsec_from_parent_zone(rr, name);
- if (r < 0)
- return r;
- if (r > 0)
- continue;
-
- /* Check if this NSEC RR proves the absence of an explicit RR under this name */
- r = dnssec_nsec_covers(rr, name);
- if (r < 0)
- return r;
- if (r > 0 && (!covering_rr || !covering_rr_authenticated)) {
- covering_rr = rr;
- covering_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED;
- }
-
- /* Check if this NSEC RR proves the absence of a wildcard RR under this name */
- r = dnssec_nsec_covers_wildcard(rr, name);
- if (r < 0)
- return r;
- if (r > 0 && (!wildcard_rr || !wildcard_rr_authenticated)) {
- wildcard_rr = rr;
- wildcard_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED;
- }
- }
-
- if (covering_rr && wildcard_rr) {
- /* If we could prove that neither the name itself, nor the wildcard at the closest encloser exists, we
- * proved the NXDOMAIN case. */
- *result = DNSSEC_NSEC_NXDOMAIN;
-
- if (authenticated)
- *authenticated = covering_rr_authenticated && wildcard_rr_authenticated;
- if (ttl)
- *ttl = MIN(covering_rr->ttl, wildcard_rr->ttl);
-
- return 0;
- }
-
- /* OK, this was not sufficient. Let's see if NSEC3 can help. */
- if (have_nsec3)
- return dnssec_test_nsec3(answer, key, result, authenticated, ttl);
-
- /* No approproate NSEC RR found, report this. */
- *result = DNSSEC_NSEC_NO_RR;
- return 0;
-}
-
-static int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, 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;
-
- if (rr->key->type != type && type != DNS_TYPE_ANY)
- 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;
-
- found = r > 0;
- break;
-
- 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;
- 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 int dnssec_test_positive_wildcard_nsec3(
- DnsAnswer *answer,
- const char *name,
- const char *source,
- const char *zone,
- bool *authenticated) {
-
- const char *next_closer = NULL;
- int r;
-
- /* Run a positive NSEC3 wildcard proof. Specifically:
- *
- * A proof that the "next closer" of the generating wildcard does not exist.
- *
- * Note a key difference between the NSEC3 and NSEC versions of the proof. NSEC RRs don't have to exist for
- * empty non-transients. NSEC3 RRs however have to. This means it's sufficient to check if the next closer name
- * exists for the NSEC3 RR and we are done.
- *
- * To prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f all we have to check is that
- * c.d.e.f does not exist. */
-
- for (;;) {
- next_closer = name;
- r = dns_name_parent(&name);
- if (r < 0)
- return r;
- if (r == 0)
- return 0;
-
- r = dns_name_equal(name, source);
- if (r < 0)
- return r;
- if (r > 0)
- break;
- }
-
- return dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC3, next_closer, zone, authenticated);
-}
-
-static int dnssec_test_positive_wildcard_nsec(
- DnsAnswer *answer,
- const char *name,
- const char *source,
- const char *zone,
- bool *_authenticated) {
-
- bool authenticated = true;
- int r;
-
- /* Run a positive NSEC wildcard proof. Specifically:
- *
- * A proof that there's neither a wildcard name nor a non-wildcard name that is a suffix of the name "name" and
- * a prefix of the synthesizing source "source" in the zone "zone".
- *
- * See RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4
- *
- * Note that if we want to prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f, then we
- * have to prove that none of the following exist:
- *
- * 1) a.b.c.d.e.f
- * 2) *.b.c.d.e.f
- * 3) b.c.d.e.f
- * 4) *.c.d.e.f
- * 5) c.d.e.f
- *
- */
-
- for (;;) {
- _cleanup_free_ char *wc = NULL;
- bool a = false;
-
- /* Check if there's an NSEC or NSEC3 RR that proves that the mame we determined is really non-existing,
- * i.e between the owner name and the next name of an NSEC RR. */
- r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, name, zone, &a);
- if (r <= 0)
- return r;
-
- authenticated = authenticated && a;
-
- /* Strip one label off */
- r = dns_name_parent(&name);
- if (r <= 0)
- return r;
-
- /* Did we reach the source of synthesis? */
- r = dns_name_equal(name, source);
- if (r < 0)
- return r;
- if (r > 0) {
- /* Successful exit */
- *_authenticated = authenticated;
- return 1;
- }
-
- /* Safety check, that the source of synthesis is still our suffix */
- r = dns_name_endswith(name, source);
- if (r < 0)
- return r;
- if (r == 0)
- return -EBADMSG;
-
- /* Replace the label we stripped off with an asterisk */
- wc = strappend("*.", name);
- if (!wc)
- return -ENOMEM;
-
- /* And check if the proof holds for the asterisk name, too */
- r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, wc, zone, &a);
- if (r <= 0)
- return r;
-
- authenticated = authenticated && a;
- /* In the next iteration we'll check the non-asterisk-prefixed version */
- }
-}
-
-int dnssec_test_positive_wildcard(
- DnsAnswer *answer,
- const char *name,
- const char *source,
- const char *zone,
- bool *authenticated) {
-
- int r;
-
- assert(name);
- assert(source);
- assert(zone);
- assert(authenticated);
-
- r = dns_answer_contains_zone_nsec3(answer, zone);
- if (r < 0)
- return r;
- if (r > 0)
- return dnssec_test_positive_wildcard_nsec3(answer, name, source, zone, authenticated);
- else
- return dnssec_test_positive_wildcard_nsec(answer, name, source, zone, authenticated);
-}
-
-#else
-
-int dnssec_verify_rrset(
- DnsAnswer *a,
- const DnsResourceKey *key,
- DnsResourceRecord *rrsig,
- DnsResourceRecord *dnskey,
- usec_t realtime,
- DnssecResult *result) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_verify_rrset_search(
- DnsAnswer *a,
- const DnsResourceKey *key,
- DnsAnswer *validated_dnskeys,
- usec_t realtime,
- DnssecResult *result,
- DnsResourceRecord **ret_rrsig) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) {
-
- return -EOPNOTSUPP;
-}
-
-int dnssec_test_positive_wildcard(
- DnsAnswer *answer,
- const char *name,
- const char *source,
- const char *zone,
- bool *authenticated) {
-
- return -EOPNOTSUPP;
-}
-
-#endif
-
-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",
- [DNSSEC_NO_SIGNATURE] = "no-signature",
- [DNSSEC_MISSING_KEY] = "missing-key",
- [DNSSEC_UNSIGNED] = "unsigned",
- [DNSSEC_FAILED_AUXILIARY] = "failed-auxiliary",
- [DNSSEC_NSEC_MISMATCH] = "nsec-mismatch",
- [DNSSEC_INCOMPATIBLE_SERVER] = "incompatible-server",
-};
-DEFINE_STRING_TABLE_LOOKUP(dnssec_result, DnssecResult);
-
-static const char* const dnssec_verdict_table[_DNSSEC_VERDICT_MAX] = {
- [DNSSEC_SECURE] = "secure",
- [DNSSEC_INSECURE] = "insecure",
- [DNSSEC_BOGUS] = "bogus",
- [DNSSEC_INDETERMINATE] = "indeterminate",
-};
-DEFINE_STRING_TABLE_LOOKUP(dnssec_verdict, DnssecVerdict);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-10 18:12:53 +0000