This implements RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4:
When we receive a response with an RRset generated from a wildcard we
need to look for one NSEC/NSEC3 RR that proves that there's no explicit RR
around before we accept the wildcard RRset as response.
This patch does a couple of things: the validation calls will now
identify wildcard signatures for us, and let us know the RRSIG used (so
that the RRSIG's signer field let's us know what the wildcard was that
generate the entry). Moreover, when iterating trough the RRsets of a
response we now employ three phases instead of just two.
a) in the first phase we only look for DNSKEYs RRs
b) in the second phase we only look for NSEC RRs
c) in the third phase we look for all kinds of RRs
Phase a) is necessary, since DNSKEYs "unlock" more signatures for us,
hence we shouldn't assume a key is missing until all DNSKEY RRs have
been processed.
Phase b) is necessary since NSECs need to be validated before we can
validate wildcard RRs due to the logic explained above.
Phase c) validates everything else. This phase also handles RRsets that
cannot be fully validated and removes them or lets the transaction fail.
There's now nsec3_hashed_domain_format() and nsec3_hashed_domain_make().
The former takes a hash value and formats it as domain, the latter takes
a domain name, hashes it and then invokes nsec3_hashed_domain_format().
This way we can reuse more code, as the formatting logic can be unified
between this call and another place.
When validating a transaction we initially collect DNSKEY, DS, SOA RRs
in the "validated_keys" list, that we need for the proofs. This includes
DNSKEY and DS data from our trust anchor database. Quite possibly we
learn that some of these DNSKEY/DS RRs have been revoked between the
time we request and collect those additional RRs and we begin the
validation step. In this case we need to make sure that the respective
DS/DNSKEY RRs are removed again from our list. This patch adds that, and
strips known revoked trust anchor RRs from the validated list before we
begin the actual validation proof, and each time we add more DNSKEY
material to it while we are doing the proof.
Instead of first iterating through all DNSKEYs in the DnsAnswer in
dns_transaction_check_revoked_trust_anchors(), and
then doing that a second time in dns_trust_anchor_check_revoked(), do so
only once in the former, and pass the dnskey we found directly to the
latter.
There's not reason to wait for checking for revoked trust anchors until
after validation, after all revoked DNSKEYs only need to be self-signed,
but not have a full trust chain.
This way, we can be sure that all trust anchor lookups we do during
validation already honour that some keys might have been revoked.
The domain name for this NSEC3 RR was originally stored in a variable
called "suffix", which was then renamed to "zone" in
d1511b3338. Hence also rename the
RR variable accordingly.
Rather than walking a list of valid values one-by-one, generate a
switch-case statement for the IN_SET() macro. This allows the compiler to
further optimize its code output, possibly by generating jump tables.
This effectively decreases the binary size slightly.
The implementation is based on macro overloading depending on the number of
arguments. h/t to the following post:
https://stackoverflow.com/questions/11761703/overloading-macro-on-number-of-arguments
- Set Smack ambient to match run label
- Set Smack netlabel host rules
Set Smack ambient to match run label
------------------------------------
Set the Smack networking ambient label to match the
run label of systemd. System services may expect to
communicate with external services over IP. Setting
the ambient label assigns that label to IP packets
that do not include CIPSO headers. This allows systemd
and the services it spawns access to unlabeled IP
packets, and hence external services.
A system may choose to restrict network access to
particular services later in the startup process.
This is easily done by resetting the ambient label
elsewhere.
Set Smack netlabel host rules
-----------------------------
If SMACK_RUN_LABEL is defined set all other hosts to be
single label hosts at the specified label. Set the loopback
address to be a CIPSO host.
If any netlabel host rules are defined in /etc/smack/netlabel.d
install them into the smackfs netlabel interface.
[Patrick Ohly: copied from https://review.tizen.org/git/?p=platform/upstream/systemd.git;a=commit;h=db4f6c9a074644aa2bf]
[Patrick Ohly: adapt to write_string_file() change in "fileio: consolidate write_string_file*()"]
[Patrick Ohly: create write_netlabel_rules() based on the original write_rules() that was removed in "smack: support smack access change-rule"]
[Patrick Ohly: adapted to upstream code review feedback: error logging, string constants]
Let's increase compatibility with many private domains by default, and
ship a default NTA list of wel-known private domains, where it is
unlikely they will be deployed as official TLD anytime soon.
This adds logic to detect cases like the Fritz!Box routers which serve
a private DNS domain "fritz.box" under the TLD "box" that does not
exist in the root servers. If this is detected DNSSEC validation is
turned off for this private domain, thus improving compatibility with
such private DNS zones.
This should be fairly secure as we first rely on the proof that .box
does not exist before this logic is applied. Nevertheless the logic is
only enabled for DNSSEC=allow-downgrade mode.
This logic does not work for routers that set up a full DNS zone directly
under a non-existing TLD, as in that case we cannot prove
that the domain is truly non-existing according to the root servers.
networkd previously knew an enum "ResolveSupport" for configuring
per-interface LLMNR support, resolved had a similar enum just called
"Support", with the same value and similar pasers.
Unify this, call the enum ResolveSupport, and port both daemons to it.
In a couple of cases we maintain configuration settings that know an on
and off state, like a boolean, plus some additional states. We generally
parse them as booleans first, and if that fails check for specific
additional values.
This adds a generalized set of macros for parsing such settings, and
ports one use in resolved and another in networkd over to it.
