Systemd/src/resolve/resolved-dns-dnssec.h
Lennart Poettering 0c85702874 resolved: partially implement RFC5011 Trust Anchor support
With this patch resolved will properly handle revoked keys, but not
augment the locally configured trust anchor database with newly learned
keys.

Specifically, resolved now refuses validating RRsets with
revoked keys, and it will remove revoked keys from the configured trust
anchors (only until reboot).

This patch does not add logic for adding new keys to the set of trust
anchors. This is a deliberate decision as this only can work with
persistent disk storage, and would result in a different update logic
for stateful and stateless systems.  Since we have to support stateless
systems anyway, and don't want to encourage two independent upgrade
paths we focus on upgrading the trust anchor database via the usual OS
upgrade logic.

Whenever a trust anchor entry is found revoked and removed from the
trust anchor a recognizable log message is written, encouraging the user
to update the trust anchor or update his operating system.
2016-01-04 22:42:10 +01:00

109 lines
3.9 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
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/>.
***/
typedef enum DnssecMode DnssecMode;
typedef enum DnssecResult DnssecResult;
#include "dns-domain.h"
#include "resolved-dns-answer.h"
#include "resolved-dns-rr.h"
enum DnssecMode {
/* No DNSSEC validation is done */
DNSSEC_NO,
/* Validate locally, if the server knows DO, but if not,
* don't. Don't trust the AD bit. If the server doesn't do
* DNSSEC properly, downgrade to non-DNSSEC operation. Of
* course, we then are vulnerable to a downgrade attack, but
* that's life and what is configured. */
DNSSEC_DOWNGRADE_OK,
/* Insist on DNSSEC server support, and rather fail than downgrading. */
DNSSEC_YES,
_DNSSEC_MODE_MAX,
_DNSSEC_MODE_INVALID = -1
};
enum DnssecResult {
/* These four are returned by dnssec_verify_rrset() */
DNSSEC_VALIDATED,
DNSSEC_INVALID,
DNSSEC_SIGNATURE_EXPIRED,
DNSSEC_UNSUPPORTED_ALGORITHM,
/* These two are added by dnssec_verify_rrset_search() */
DNSSEC_NO_SIGNATURE,
DNSSEC_MISSING_KEY,
/* These two are added by the DnsTransaction logic */
DNSSEC_UNSIGNED,
DNSSEC_FAILED_AUXILIARY,
DNSSEC_NSEC_MISMATCH,
DNSSEC_INCOMPATIBLE_SERVER,
_DNSSEC_RESULT_MAX,
_DNSSEC_RESULT_INVALID = -1
};
#define DNSSEC_CANONICAL_HOSTNAME_MAX (DNS_HOSTNAME_MAX + 2)
/* The longest digest we'll ever generate, of all digest algorithms we support */
#define DNSSEC_HASH_SIZE_MAX (MAX(20, 32))
int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok);
int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig);
int dnssec_verify_rrset(DnsAnswer *answer, const DnsResourceKey *key, DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, usec_t realtime, DnssecResult *result);
int dnssec_verify_rrset_search(DnsAnswer *answer, const DnsResourceKey *key, DnsAnswer *validated_dnskeys, usec_t realtime, DnssecResult *result);
int dnssec_verify_dnskey(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke);
int dnssec_verify_dnskey_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds);
int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key);
uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke);
int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max);
int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret);
typedef enum DnssecNsecResult {
DNSSEC_NSEC_NO_RR, /* No suitable NSEC/NSEC3 RR found */
DNSSEC_NSEC_CNAME, /* Would be NODATA, but for the existence of a CNAME RR */
DNSSEC_NSEC_UNSUPPORTED_ALGORITHM,
DNSSEC_NSEC_NXDOMAIN,
DNSSEC_NSEC_NODATA,
DNSSEC_NSEC_FOUND,
DNSSEC_NSEC_OPTOUT,
} DnssecNsecResult;
int dnssec_test_nsec(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated);
const char* dnssec_mode_to_string(DnssecMode m) _const_;
DnssecMode dnssec_mode_from_string(const char *s) _pure_;
const char* dnssec_result_to_string(DnssecResult m) _const_;
DnssecResult dnssec_result_from_string(const char *s) _pure_;