diff options
Diffstat (limited to 'src/resolve/resolved-dns-trust-anchor.c')
| -rw-r--r-- | src/resolve/resolved-dns-trust-anchor.c | 746 |
1 files changed, 0 insertions, 746 deletions
diff --git a/src/resolve/resolved-dns-trust-anchor.c b/src/resolve/resolved-dns-trust-anchor.c deleted file mode 100644 index 9917b9e984..0000000000 --- a/src/resolve/resolved-dns-trust-anchor.c +++ /dev/null @@ -1,746 +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/>. -***/ - -#include <sd-messages.h> - -#include "alloc-util.h" -#include "conf-files.h" -#include "def.h" -#include "dns-domain.h" -#include "fd-util.h" -#include "fileio.h" -#include "hexdecoct.h" -#include "parse-util.h" -#include "resolved-dns-trust-anchor.h" -#include "resolved-dns-dnssec.h" -#include "set.h" -#include "string-util.h" -#include "strv.h" - -static const char trust_anchor_dirs[] = CONF_PATHS_NULSTR("dnssec-trust-anchors.d"); - -/* The DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved December 2015 */ -static const uint8_t root_digest[] = - { 0x49, 0xAA, 0xC1, 0x1D, 0x7B, 0x6F, 0x64, 0x46, 0x70, 0x2E, 0x54, 0xA1, 0x60, 0x73, 0x71, 0x60, - 0x7A, 0x1A, 0x41, 0x85, 0x52, 0x00, 0xFD, 0x2C, 0xE1, 0xCD, 0xDE, 0x32, 0xF2, 0x4E, 0x8F, 0xB5 }; - -static bool dns_trust_anchor_knows_domain_positive(DnsTrustAnchor *d, const char *name) { - assert(d); - - /* Returns true if there's an entry for the specified domain - * name in our trust anchor */ - - return - hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DNSKEY, name)) || - hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name)); -} - -static int dns_trust_anchor_add_builtin_positive(DnsTrustAnchor *d) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - int r; - - assert(d); - - r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); - if (r < 0) - return r; - - /* Only add the built-in trust anchor if there's neither a DS - * nor a DNSKEY defined for the root domain. That way users - * have an easy way to override the root domain DS/DNSKEY - * data. */ - if (dns_trust_anchor_knows_domain_positive(d, ".")) - return 0; - - /* Add the RR from https://data.iana.org/root-anchors/root-anchors.xml */ - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, ""); - if (!rr) - return -ENOMEM; - - rr->ds.key_tag = 19036; - rr->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; - rr->ds.digest_type = DNSSEC_DIGEST_SHA256; - rr->ds.digest_size = sizeof(root_digest); - rr->ds.digest = memdup(root_digest, rr->ds.digest_size); - if (!rr->ds.digest) - return -ENOMEM; - - answer = dns_answer_new(1); - if (!answer) - return -ENOMEM; - - r = dns_answer_add(answer, rr, 0, DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - - r = hashmap_put(d->positive_by_key, rr->key, answer); - if (r < 0) - return r; - - answer = NULL; - return 0; -} - -static int dns_trust_anchor_add_builtin_negative(DnsTrustAnchor *d) { - - static const char private_domains[] = - /* RFC 6761 says that .test is a special domain for - * testing and not to be installed in the root zone */ - "test\0" - - /* RFC 6761 says that these reverse IP lookup ranges - * are for private addresses, and hence should not - * show up in the root zone */ - "10.in-addr.arpa\0" - "16.172.in-addr.arpa\0" - "17.172.in-addr.arpa\0" - "18.172.in-addr.arpa\0" - "19.172.in-addr.arpa\0" - "20.172.in-addr.arpa\0" - "21.172.in-addr.arpa\0" - "22.172.in-addr.arpa\0" - "23.172.in-addr.arpa\0" - "24.172.in-addr.arpa\0" - "25.172.in-addr.arpa\0" - "26.172.in-addr.arpa\0" - "27.172.in-addr.arpa\0" - "28.172.in-addr.arpa\0" - "29.172.in-addr.arpa\0" - "30.172.in-addr.arpa\0" - "31.172.in-addr.arpa\0" - "168.192.in-addr.arpa\0" - - /* The same, but for IPv6. */ - "d.f.ip6.arpa\0" - - /* RFC 6762 reserves the .local domain for Multicast - * DNS, it hence cannot appear in the root zone. (Note - * that we by default do not route .local traffic to - * DNS anyway, except when a configured search domain - * suggests so.) */ - "local\0" - - /* These two are well known, popular private zone - * TLDs, that are blocked from delegation, according - * to: - * http://icannwiki.com/Name_Collision#NGPC_Resolution - * - * There's also ongoing work on making this official - * in an RRC: - * https://www.ietf.org/archive/id/draft-chapin-additional-reserved-tlds-02.txt */ - "home\0" - "corp\0" - - /* The following four TLDs are suggested for private - * zones in RFC 6762, Appendix G, and are hence very - * unlikely to be made official TLDs any day soon */ - "lan\0" - "intranet\0" - "internal\0" - "private\0"; - - const char *name; - int r; - - assert(d); - - /* Only add the built-in trust anchor if there's no negative - * trust anchor defined at all. This enables easy overriding - * of negative trust anchors. */ - - if (set_size(d->negative_by_name) > 0) - return 0; - - r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); - if (r < 0) - return r; - - /* We add a couple of domains as default negative trust - * anchors, where it's very unlikely they will be installed in - * the root zone. If they exist they must be private, and thus - * unsigned. */ - - NULSTR_FOREACH(name, private_domains) { - - if (dns_trust_anchor_knows_domain_positive(d, name)) - continue; - - r = set_put_strdup(d->negative_by_name, name); - if (r < 0) - return r; - } - - return 0; -} - -static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - _cleanup_free_ char *domain = NULL, *class = NULL, *type = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - DnsAnswer *old_answer = NULL; - const char *p = s; - int r; - - assert(d); - assert(line); - - r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); - if (r < 0) - return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line); - - if (!dns_name_is_valid(domain)) { - log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); - return -EINVAL; - } - - r = extract_many_words(&p, NULL, 0, &class, &type, NULL); - if (r < 0) - return log_warning_errno(r, "Unable to parse class and type in line %s:%u: %m", path, line); - if (r != 2) { - log_warning("Missing class or type in line %s:%u", path, line); - return -EINVAL; - } - - if (!strcaseeq(class, "IN")) { - log_warning("RR class %s is not supported, ignoring line %s:%u.", class, path, line); - return -EINVAL; - } - - if (strcaseeq(type, "DS")) { - _cleanup_free_ char *key_tag = NULL, *algorithm = NULL, *digest_type = NULL, *digest = NULL; - _cleanup_free_ void *dd = NULL; - uint16_t kt; - int a, dt; - size_t l; - - r = extract_many_words(&p, NULL, 0, &key_tag, &algorithm, &digest_type, &digest, NULL); - if (r < 0) { - log_warning_errno(r, "Failed to parse DS parameters on line %s:%u: %m", path, line); - return -EINVAL; - } - if (r != 4) { - log_warning("Missing DS parameters on line %s:%u", path, line); - return -EINVAL; - } - - r = safe_atou16(key_tag, &kt); - if (r < 0) - return log_warning_errno(r, "Failed to parse DS key tag %s on line %s:%u: %m", key_tag, path, line); - - a = dnssec_algorithm_from_string(algorithm); - if (a < 0) { - log_warning("Failed to parse DS algorithm %s on line %s:%u", algorithm, path, line); - return -EINVAL; - } - - dt = dnssec_digest_from_string(digest_type); - if (dt < 0) { - log_warning("Failed to parse DS digest type %s on line %s:%u", digest_type, path, line); - return -EINVAL; - } - - r = unhexmem(digest, strlen(digest), &dd, &l); - if (r < 0) { - log_warning("Failed to parse DS digest %s on line %s:%u", digest, path, line); - return -EINVAL; - } - - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, domain); - if (!rr) - return log_oom(); - - rr->ds.key_tag = kt; - rr->ds.algorithm = a; - rr->ds.digest_type = dt; - rr->ds.digest_size = l; - rr->ds.digest = dd; - dd = NULL; - - } else if (strcaseeq(type, "DNSKEY")) { - _cleanup_free_ char *flags = NULL, *protocol = NULL, *algorithm = NULL, *key = NULL; - _cleanup_free_ void *k = NULL; - uint16_t f; - size_t l; - int a; - - r = extract_many_words(&p, NULL, 0, &flags, &protocol, &algorithm, &key, NULL); - if (r < 0) - return log_warning_errno(r, "Failed to parse DNSKEY parameters on line %s:%u: %m", path, line); - if (r != 4) { - log_warning("Missing DNSKEY parameters on line %s:%u", path, line); - return -EINVAL; - } - - if (!streq(protocol, "3")) { - log_warning("DNSKEY Protocol is not 3 on line %s:%u", path, line); - return -EINVAL; - } - - r = safe_atou16(flags, &f); - if (r < 0) - return log_warning_errno(r, "Failed to parse DNSKEY flags field %s on line %s:%u", flags, path, line); - if ((f & DNSKEY_FLAG_ZONE_KEY) == 0) { - log_warning("DNSKEY lacks zone key bit set on line %s:%u", path, line); - return -EINVAL; - } - if ((f & DNSKEY_FLAG_REVOKE)) { - log_warning("DNSKEY is already revoked on line %s:%u", path, line); - return -EINVAL; - } - - a = dnssec_algorithm_from_string(algorithm); - if (a < 0) { - log_warning("Failed to parse DNSKEY algorithm %s on line %s:%u", algorithm, path, line); - return -EINVAL; - } - - r = unbase64mem(key, strlen(key), &k, &l); - if (r < 0) - return log_warning_errno(r, "Failed to parse DNSKEY key data %s on line %s:%u", key, path, line); - - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, domain); - if (!rr) - return log_oom(); - - rr->dnskey.flags = f; - rr->dnskey.protocol = 3; - rr->dnskey.algorithm = a; - rr->dnskey.key_size = l; - rr->dnskey.key = k; - k = NULL; - - } else { - log_warning("RR type %s is not supported, ignoring line %s:%u.", type, path, line); - return -EINVAL; - } - - if (!isempty(p)) { - log_warning("Trailing garbage on line %s:%u, ignoring line.", path, line); - return -EINVAL; - } - - r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); - if (r < 0) - return log_oom(); - - old_answer = hashmap_get(d->positive_by_key, rr->key); - answer = dns_answer_ref(old_answer); - - r = dns_answer_add_extend(&answer, rr, 0, DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return log_error_errno(r, "Failed to add trust anchor RR: %m"); - - r = hashmap_replace(d->positive_by_key, rr->key, answer); - if (r < 0) - return log_error_errno(r, "Failed to add answer to trust anchor: %m"); - - old_answer = dns_answer_unref(old_answer); - answer = NULL; - - return 0; -} - -static int dns_trust_anchor_load_negative(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { - _cleanup_free_ char *domain = NULL; - const char *p = s; - int r; - - assert(d); - assert(line); - - r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); - if (r < 0) - return log_warning_errno(r, "Unable to parse line %s:%u: %m", path, line); - - if (!dns_name_is_valid(domain)) { - log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); - return -EINVAL; - } - - if (!isempty(p)) { - log_warning("Trailing garbage at line %s:%u, ignoring line.", path, line); - return -EINVAL; - } - - r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); - if (r < 0) - return log_oom(); - - r = set_put(d->negative_by_name, domain); - if (r < 0) - return log_oom(); - if (r > 0) - domain = NULL; - - return 0; -} - -static int dns_trust_anchor_load_files( - DnsTrustAnchor *d, - const char *suffix, - int (*loader)(DnsTrustAnchor *d, const char *path, unsigned n, const char *line)) { - - _cleanup_strv_free_ char **files = NULL; - char **f; - int r; - - assert(d); - assert(suffix); - assert(loader); - - r = conf_files_list_nulstr(&files, suffix, NULL, trust_anchor_dirs); - if (r < 0) - return log_error_errno(r, "Failed to enumerate %s trust anchor files: %m", suffix); - - STRV_FOREACH(f, files) { - _cleanup_fclose_ FILE *g = NULL; - char line[LINE_MAX]; - unsigned n = 0; - - g = fopen(*f, "r"); - if (!g) { - if (errno == ENOENT) - continue; - - log_warning_errno(errno, "Failed to open %s: %m", *f); - continue; - } - - FOREACH_LINE(line, g, log_warning_errno(errno, "Failed to read %s, ignoring: %m", *f)) { - char *l; - - n++; - - l = strstrip(line); - if (isempty(l)) - continue; - - if (*l == ';') - continue; - - (void) loader(d, *f, n, l); - } - } - - return 0; -} - -static int domain_name_cmp(const void *a, const void *b) { - char **x = (char**) a, **y = (char**) b; - - return dns_name_compare_func(*x, *y); -} - -static int dns_trust_anchor_dump(DnsTrustAnchor *d) { - DnsAnswer *a; - Iterator i; - - assert(d); - - if (hashmap_isempty(d->positive_by_key)) - log_info("No positive trust anchors defined."); - else { - log_info("Positive Trust Anchors:"); - HASHMAP_FOREACH(a, d->positive_by_key, i) { - DnsResourceRecord *rr; - - DNS_ANSWER_FOREACH(rr, a) - log_info("%s", dns_resource_record_to_string(rr)); - } - } - - if (set_isempty(d->negative_by_name)) - log_info("No negative trust anchors defined."); - else { - _cleanup_free_ char **l = NULL, *j = NULL; - - l = set_get_strv(d->negative_by_name); - if (!l) - return log_oom(); - - qsort_safe(l, set_size(d->negative_by_name), sizeof(char*), domain_name_cmp); - - j = strv_join(l, " "); - if (!j) - return log_oom(); - - log_info("Negative trust anchors: %s", j); - } - - return 0; -} - -int dns_trust_anchor_load(DnsTrustAnchor *d) { - int r; - - assert(d); - - /* If loading things from disk fails, we don't consider this fatal */ - (void) dns_trust_anchor_load_files(d, ".positive", dns_trust_anchor_load_positive); - (void) dns_trust_anchor_load_files(d, ".negative", dns_trust_anchor_load_negative); - - /* However, if the built-in DS fails, then we have a problem. */ - r = dns_trust_anchor_add_builtin_positive(d); - if (r < 0) - return log_error_errno(r, "Failed to add built-in positive trust anchor: %m"); - - r = dns_trust_anchor_add_builtin_negative(d); - if (r < 0) - return log_error_errno(r, "Failed to add built-in negative trust anchor: %m"); - - dns_trust_anchor_dump(d); - - return 0; -} - -void dns_trust_anchor_flush(DnsTrustAnchor *d) { - DnsAnswer *a; - DnsResourceRecord *rr; - - assert(d); - - while ((a = hashmap_steal_first(d->positive_by_key))) - dns_answer_unref(a); - d->positive_by_key = hashmap_free(d->positive_by_key); - - while ((rr = set_steal_first(d->revoked_by_rr))) - dns_resource_record_unref(rr); - d->revoked_by_rr = set_free(d->revoked_by_rr); - - d->negative_by_name = set_free_free(d->negative_by_name); -} - -int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey *key, DnsAnswer **ret) { - DnsAnswer *a; - - assert(d); - assert(key); - assert(ret); - - /* We only serve DS and DNSKEY RRs. */ - if (!IN_SET(key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) - return 0; - - a = hashmap_get(d->positive_by_key, key); - if (!a) - return 0; - - *ret = dns_answer_ref(a); - return 1; -} - -int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name) { - assert(d); - assert(name); - - return set_contains(d->negative_by_name, name); -} - -static int dns_trust_anchor_revoked_put(DnsTrustAnchor *d, DnsResourceRecord *rr) { - int r; - - assert(d); - - r = set_ensure_allocated(&d->revoked_by_rr, &dns_resource_record_hash_ops); - if (r < 0) - return r; - - r = set_put(d->revoked_by_rr, rr); - if (r < 0) - return r; - if (r > 0) - dns_resource_record_ref(rr); - - return r; -} - -static int dns_trust_anchor_remove_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { - _cleanup_(dns_answer_unrefp) DnsAnswer *new_answer = NULL; - DnsAnswer *old_answer; - int r; - - /* Remember that this is a revoked trust anchor RR */ - r = dns_trust_anchor_revoked_put(d, rr); - if (r < 0) - return r; - - /* Remove this from the positive trust anchor */ - old_answer = hashmap_get(d->positive_by_key, rr->key); - if (!old_answer) - return 0; - - new_answer = dns_answer_ref(old_answer); - - r = dns_answer_remove_by_rr(&new_answer, rr); - if (r <= 0) - return r; - - /* We found the key! Warn the user */ - log_struct(LOG_WARNING, - LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_TRUST_ANCHOR_REVOKED), - LOG_MESSAGE("DNSSEC Trust anchor %s has been revoked. Please update the trust anchor, or upgrade your operating system."), strna(dns_resource_record_to_string(rr)), - "TRUST_ANCHOR=%s", dns_resource_record_to_string(rr), - NULL); - - if (dns_answer_size(new_answer) <= 0) { - assert_se(hashmap_remove(d->positive_by_key, rr->key) == old_answer); - dns_answer_unref(old_answer); - return 1; - } - - r = hashmap_replace(d->positive_by_key, new_answer->items[0].rr->key, new_answer); - if (r < 0) - return r; - - new_answer = NULL; - dns_answer_unref(old_answer); - return 1; -} - -static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceRecord *revoked_dnskey) { - DnsAnswer *a; - int r; - - assert(d); - assert(revoked_dnskey); - assert(revoked_dnskey->key->type == DNS_TYPE_DNSKEY); - assert(revoked_dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE); - - a = hashmap_get(d->positive_by_key, revoked_dnskey->key); - if (a) { - DnsResourceRecord *anchor; - - /* First, look for the precise DNSKEY in our trust anchor database */ - - DNS_ANSWER_FOREACH(anchor, a) { - - if (anchor->dnskey.protocol != revoked_dnskey->dnskey.protocol) - continue; - - if (anchor->dnskey.algorithm != revoked_dnskey->dnskey.algorithm) - continue; - - if (anchor->dnskey.key_size != revoked_dnskey->dnskey.key_size) - continue; - - /* Note that we allow the REVOKE bit to be - * different! It will be set in the revoked - * key, but unset in our version of it */ - if (((anchor->dnskey.flags ^ revoked_dnskey->dnskey.flags) | DNSKEY_FLAG_REVOKE) != DNSKEY_FLAG_REVOKE) - continue; - - if (memcmp(anchor->dnskey.key, revoked_dnskey->dnskey.key, anchor->dnskey.key_size) != 0) - continue; - - dns_trust_anchor_remove_revoked(d, anchor); - break; - } - } - - a = hashmap_get(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(revoked_dnskey->key->class, DNS_TYPE_DS, dns_resource_key_name(revoked_dnskey->key))); - if (a) { - DnsResourceRecord *anchor; - - /* Second, look for DS RRs matching this DNSKEY in our trust anchor database */ - - DNS_ANSWER_FOREACH(anchor, a) { - - /* We set mask_revoke to true here, since our - * DS fingerprint will be the one of the - * unrevoked DNSKEY, but the one we got passed - * here has the bit set. */ - r = dnssec_verify_dnskey_by_ds(revoked_dnskey, anchor, true); - if (r < 0) - return r; - if (r == 0) - continue; - - dns_trust_anchor_remove_revoked(d, anchor); - break; - } - } - - return 0; -} - -int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) { - DnsResourceRecord *rrsig; - int r; - - assert(d); - assert(dnskey); - - /* Looks if "dnskey" is a self-signed RR that has been revoked - * and matches one of our trust anchor entries. If so, removes - * it from the trust anchor and returns > 0. */ - - if (dnskey->key->type != DNS_TYPE_DNSKEY) - return 0; - - /* Is this DNSKEY revoked? */ - if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) - return 0; - - /* Could this be interesting to us at all? If not, - * there's no point in looking for and verifying a - * self-signed RRSIG. */ - if (!dns_trust_anchor_knows_domain_positive(d, dns_resource_key_name(dnskey->key))) - return 0; - - /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */ - DNS_ANSWER_FOREACH(rrsig, rrs) { - DnssecResult result; - - if (rrsig->key->type != DNS_TYPE_RRSIG) - continue; - - r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); - if (r < 0) - return r; - if (r == 0) - continue; - - r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result); - if (r < 0) - return r; - if (result != DNSSEC_VALIDATED) - continue; - - /* Bingo! This is a revoked self-signed DNSKEY. Let's - * see if this precise one exists in our trust anchor - * database, too. */ - r = dns_trust_anchor_check_revoked_one(d, dnskey); - if (r < 0) - return r; - - return 1; - } - - return 0; -} - -int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { - assert(d); - - if (!IN_SET(rr->key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) - return 0; - - return set_contains(d->revoked_by_rr, rr); -} |