https://tools.ietf.org/html/rfc1035#section-2.3.1 says (approximately)
that only letters, numbers, and non-leading non-trailing dashes are allowed
(for entries with A/AAAA records). We set no restrictions.
hosts(5) says:
> Host names may contain only alphanumeric characters, minus signs ("-"), and
> periods ("."). They must begin with an alphabetic character and end with an
> alphanumeric character.
nss-files follows those rules, and will ignore names in /etc/hosts that do not
follow this rule.
Let's follow the documented rules for /etc/hosts. In particular, this makes us
consitent with nss-files, reducing surprises for the user.
I'm pretty sure we should apply stricter filtering to names received over DNS
and LLMNR and MDNS, but it's a bigger project, because the rules differ
depepending on which level the label appears (rules for top-level names are
stricter), and this patch takes the minimalistic approach and only changes
behaviour for /etc/hosts.
Escape syntax is also disallowed in /etc/hosts, even if the resulting character
would be allowed. Other tools that parse /etc/hosts do not support this, and
there is no need to use it because no allowed characters benefit from escaping.
This function doesn't really implement ordering, but CMP() is still fine to use
there. Keep the comment in place, just update it slightly to indicate that.
Looked for definitions of functions using the *_compare_func() suffix.
Tested:
- Unit tests passed (ninja -C build/ test)
- Installed this build and booted with it.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
RFC 8080 describes how to use EdDSA keys and signatures in DNSSEC. It
uses the curves Ed25519 and Ed448. Libgcrypt 1.8.1 does not support
Ed448, so only the Ed25519 is supported at the moment. Once Libgcrypt
supports Ed448, support for it can be trivially added to resolve.
When we return the full RR wire data, let's make sure the TTL included in it is
adjusted by the time the RR sat in the cache.
As an optimization we do this only for ResolveRecord() and not for
ResolveHostname() and friends, since adjusting the TTL means copying the RR
object, and we don#t want to do that if there's no reason to.
(ResolveHostname() and friends don't return the TTL hence there's no reason to
in that case)
https://tools.ietf.org/html/rfc6698#section-2.2 says:
> The certificate association data field MUST be represented as a string
> of hexadecimal characters. Whitespace is allowed within the string of
> hexadecimal characters
When the buffer is allocated on the stack we do not have to check for
failure everywhere. This is especially useful in debug statements, because
we can put dns_resource_key_to_string() call in the debug statement, and
we do not need a seperate if (log_level >= LOG_DEBUG) for the conversion.
dns_resource_key_to_string() is changed not to provide any whitespace
padding. Most callers were stripping the whitespace with strstrip(),
and it did not look to well anyway. systemd-resolve output is not column
aligned anymore.
The result of the conversion is not stored in DnsTransaction object
anymore. It is used only for debugging, so it seems fine to generate it
when needed.
Various debug statements are extended to provide more information.
Left-over unknown flags are printed numerically. Otherwise,
it wouldn't be known what bits are remaining without knowning
what the known bits are.
A test case is added to verify the flag printing code:
============== src/resolve/test-data/fake-caa.pkts ==============
google.com. IN CAA 0 issue "symantec.com"
google.com. IN CAA 128 issue "symantec.com"
-- Flags: critical
google.com. IN CAA 129 issue "symantec.com"
-- Flags: critical 1
google.com. IN CAA 22 issue "symantec.com"
-- Flags: 22
Packets are stored in a simple format:
<size> <packet-wire-format> <size> <packet-wire-format> ...
Packets for some example domains are dumped, to test rr code for various
record types. Currently:
A
AAAA
CAA
DNSKEY
LOC
MX
NS
NSEC
OPENPGPKEY
SOA
SPF
TXT
The hashing code is executed, but results are not checked.
Also build other tests in src/resolve only with --enable-resolve.
We try to fit the lengthy key data into available space. If the other
fields take less than half of the available columns, we use align everything
in the remaining columns. Otherwise, we put everything after a newline,
indented with 8 spaces.
This is similar to dig and other tools do.
$ COLUMNS=78 ./systemd-resolve -t any .
. IN SOA a.root-servers.net nstld.verisign-grs.com 2016012701 1800 900 604800 86400
. IN RRSIG SOA RSASHA256 0 86400 20160206170000 20160127160000 54549
S1uhUoBAReAFi5wH/KczVDgwLb+B9Zp57dSYj9aX4XxBhKuzccIducpg0wWXhjCRAWuzY
fQ/J2anm4+C4BLUTdlytPIemd42SUffQk2WGuuukI8e67nkrNF3WFtoeXQ4OchsyO24t2
rxi682Zo9ViqmXZ+MSsjWKt1jdem4noaY=
. IN NS h.root-servers.net
. IN NS k.root-servers.net
. IN NS e.root-servers.net
. IN NS c.root-servers.net
. IN NS b.root-servers.net
. IN NS g.root-servers.net
. IN NS d.root-servers.net
. IN NS f.root-servers.net
. IN NS i.root-servers.net
. IN NS j.root-servers.net
. IN NS m.root-servers.net
. IN NS a.root-servers.net
. IN NS l.root-servers.net
. IN RRSIG NS RSASHA256 0 518400 20160206170000 20160127160000 54549
rxhmTVKUgs72G3VzL+1JRuD0nGLIrPM+ISfmUx0eYUH5wZD5XMu2X+8PfkAsEQT1dziPs
ac+zK1YZPbNgr3yGI5H/wEbK8S7DmlvO+/I9WKTLp/Zxn3yncvnTOdjFMZxkAqHbjVOm+
BFz7RjQuvCQlEJX4PQBFphgEnkiOnmMdI=
. IN NSEC aaa ( NS SOA RRSIG NSEC DNSKEY )
. IN RRSIG NSEC RSASHA256 0 86400 20160206170000 20160127160000 54549
HY49/nGkUJJP1zLmH33MIKnkNH33jQ7bsAHE9itEjvC4wfAzgq8+Oh9fjYav1R1GDeJ2Z
HOu3Z2uDRif10R8RsmZbxyZXJs7eHui9KcAMot1U4uKCCooC/5GImf+oUDbvaraUCMQRU
D3mUzoa0BGWfxgZEDqZ55raVFT/olEgG8=
. IN DNSKEY 257 3 RSASHA256 AwEAAagAIKlVZrpC6Ia7gEzahOR+9W29euxhJhVVLOyQbSEW0
O8gcCjFFVQUTf6v58fLjwBd0YI0EzrAcQqBGCzh/RStIoO8g0
NfnfL2MTJRkxoXbfDaUeVPQuYEhg37NZWAJQ9VnMVDxP/VHL4
96M/QZxkjf5/Efucp2gaDX6RS6CXpoY68LsvPVjR0ZSwzz1ap
AzvN9dlzEheX7ICJBBtuA6G3LQpzW5hOA2hzCTMjJPJ8LbqF6
dsV6DoBQzgul0sGIcGOYl7OyQdXfZ57relSQageu+ipAdTTJ2
5AsRTAoub8ONGcLmqrAmRLKBP1dfwhYB4N7knNnulqQxA+Uk1
ihz0=
. IN DNSKEY 256 3 RSASHA256 AwEAAbr/RV0stAWYbmKOldjShp4AOQGOyY3ATI1NUpP4X1qBs
6lsXpc+1ABgv6zkg02IktjZrHnmD0HsElu3wqXMrT5KL1W7Sp
mg0Pou9WZ8QttdTKXwrVXrASsaGI2z/pLBSnK8EdzqUrTVxY4
TEGZtxV519isM06CCMihxTn5cfFBF
. IN RRSIG DNSKEY RSASHA256 0 172800 20160204235959 20160121000000 19036
XYewrVdYKRDfZptAATwT+W4zng04riExV36+z04kok09W0RmOtDlQrlrwHLlD2iN/zYpg
EqGgDF5T2xlrQdNpn+PFHhypHM7NQAgLTrwmiw6mGbV0bsZN3rhFxHwW7QVUFAvo9eNVu
INrjm+sArwxq3DnPkmA+3K4ikKD2iiT/jT91VYr9SHFqXXURccLjI+nmaE7m31hXcirX/
r5i3J+B4Fx4415IavSD72r7cmruocnCVjcp+ZAUKeMyW+RwigzevLz3oEcCZ4nrTpGLEj
wFaVePYoP+rfdmfLfTdmkkm4APRJa2My3XOdGFlgNS1pW1pH4az5LapLE2vMO7p1aQ==
-- Information acquired via protocol DNS in 14.4ms.
-- Data is authenticated: no
Quite often we read the same RR key multiple times from the same message. Try to replace them by a single object when
we notice this. Do so again when we add things to the cache.
This should reduce memory consumption a tiny bit.
This fills in the last few gaps:
- When checking if a domain is non-existing, also check that no wildcard for it exists
- Ensure we don't base "covering" tests on NSEC RRs from a parent zone
- Refuse to accept expanded wildcard NSEC RRs for absence proofs.
Having this information available is useful when we need to check whether various RRs are suitable for proofs. This
information is stored in the RRs as number of labels to skip from the beginning of the owner name to reach the
synthesizing source/signer. Simple accessor calls are then added to retrieve the signer/source from the RR using this
information.
This also moves validation of a a number of RRSIG parameters into a new call dnssec_rrsig_prepare() that as side-effect
initializes the two numeric values.
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.
This adds negative trust anchor support and allows reading trust anchor
data from disk, from files
/etc/systemd/dnssec-trust-anchors.d/*.positive and
/etc/systemd/dnssec-trust-anchros.d/*.negative, as well as the matching
counterparts in /usr/lib and /run.
The positive trust anchor files are more or less compatible to normal
DNS zone files containing DNSKEY and DS RRs. The negative trust anchor
files contain only new-line separated hostnames for which to require no
signing.
By default no trust anchor files are installed, in which case the
compiled-in root domain DS RR is used, as before. As soon as at least
one positive root anchor for the root is defined via trust anchor files
this buil-in DS RR is not added though.
