Create keys according to DNSSEC policy. Zones configured with
'dnssec-policy' will allow 'named' to create DNSSEC keys (similar
to dnssec-keymgr) if not available.
KEY ROLLOVER
Rather than determining the desired state from timing metadata,
add a key state goal. Any keys that are created or picked from the
key ring and selected to be a successor has its key state goal set
to OMNIPRESENT (this key wants to be signing!). At the same time,
a key that is being retired has its key state goal set to HIDDEN.
The keymgr state machine with the three rules will make sure no
introduction or withdrawal of DNSSEC records happens too soon.
KEY TIMINGS
All timings are based on RFC 7583.
The keymgr will return when the next action is happening so
that the zone can set the proper rekey event. Prior to this change
the rekey event will run every hour by default (configurable),
but with kasp we can determine exactly when we need to run again.
Matthijs Mekking [Thu, 17 Oct 2019 08:21:12 +0000 (10:21 +0200)]
Useful dst_key functions
Add a couple of dst_key functions for determining hints that
consider key states if they are available.
- dst_key_is_unused:
A key has no timing metadata set other than Created.
- dst_key_is_published:
A key has publish timing metadata <= now, DNSKEY state in
RUMOURED or OMNIPRESENT.
- dst_key_is_active:
A key has active timing metadata <= now, RRSIG state in
RUMOURED or OMNIPRESENT.
- dst_key_is_signing:
KSK is_signing and is_active means different things than
for a ZSK. A ZSK is active means it is also signing, but
a KSK always signs its DNSKEY RRset but is considered
active if its DS is present (rumoured or omnipresent).
- dst_key_is_revoked:
A key has revoke timing metadata <= now.
- dst_key_is_removed:
A key has delete timing metadata <= now, DNSKEY state in
UNRETENTIVE or HIDDEN.
Matthijs Mekking [Wed, 16 Oct 2019 16:36:38 +0000 (18:36 +0200)]
kasp: Expose more key timings
When doing rollover in a timely manner we need to have access to the
relevant kasp configured durations.
Most of these are simple get functions, but 'dns_kasp_signdelay'
will calculate the maximum time that is needed with this policy to
resign the complete zone (taking into account the refresh interval
and signature validity).
When signing a zone with dnssec-policy, we don't mind DNSSEC records.
This is useful for testing purposes, and perhaps it is better to
signal this behavior with a different configuration option.
Introduce a new option '-s' for dnssec-settime that when manipulating
timing metadata, it also updates the key state file.
For testing purposes, add options to dnssec-settime to set key
states and when they last changed.
The dst code adds ways to write and read the new key states and
timing metadata. It updates the parsing code for private key files
to not parse the newly introduced metadata (these are for state
files only).
Introduce key goal (the state the key wants to be in).
Write functions to access various elements of the kasp structure,
and the kasp keys. This in preparation of code in dnssec-keygen,
dnssec-settime, named...
Add a number of metadata variables (lifetime, ksk and zsk role).
For the roles we add a new type of metadata (booleans).
Add a function to write the state of the key to a separate file.
Only write out known metadata to private file. With the
introduction of the numeric metadata "Lifetime", adjust the write
private key file functionality to only write out metadata it knows
about.
Code and documentation were not in line:
- Remove -z option from code
- Remove -k option from docbook
- Add -d option to docbook
- Add -T option to docbook
This stores the dnssec-policy configuration and adds methods to
create, destroy, and attach/detach, as well as find a policy with
the same name in a list.
Also, add structures and functions for creating and destroying
kasp keys.
This commit introduces the initial `dnssec-policy` configuration
statement. It has an initial set of options to deal with signature
and key maintenance.
Add some checks to ensure that dnssec-policy is configured at the
right locations, and that policies referenced to in zone statements
actually exist.
Add some checks that when a user adds the new `dnssec-policy`
configuration, it will no longer contain existing DNSSEC
configuration options. Specifically: `inline-signing`,
`auto-dnssec`, `dnssec-dnskey-kskonly`, `dnssec-secure-to-insecure`,
`update-check-ksk`, `dnssec-update-mode`, `dnskey-sig-validity`,
and `sig-validity-interval`.
Test a good kasp configuration, and some bad configurations.
The ttlval configuration types are replaced by duration configuration
types. The duration is an ISO 8601 duration that is going to be used
for DNSSEC key timings such as key lifetimes, signature resign
intervals and refresh periods, etc. But it is also still allowed to
use the BIND ttlval ways of configuring intervals (number plus
optional unit).
A duration is stored as an array of 7 different time parts.
A duration can either be expressed in weeks, or in a combination of
the other datetime indicators.
Add several unit tests to ensure the correct value is parsed given
different string values.
This commit does not change anything significant, it just makes
the file more readable in preparation for upcoming changes related
to the `dnssec-policy` configuration option.
Michał Kępień [Wed, 6 Nov 2019 14:31:47 +0000 (15:31 +0100)]
Do not use <sys/sysctl.h> on Linux
glibc 2.30 deprecated the <sys/sysctl.h> header [1]. However, that
header is still used on other Unix-like systems, so only prevent it from
being used on Linux, in order to prevent compiler warnings from being
triggered.
Michał Kępień [Wed, 6 Nov 2019 14:22:08 +0000 (15:22 +0100)]
Add assert_int_equal() shell function
Add a shell function which is used in the "tcp" system test, but has
been accidentally omitted from !2425. Make sure the function does not
change the value of "ret" itself, so that the caller can decide what to
do with the function's return value.
Witold Kręcicki [Wed, 9 Oct 2019 15:38:44 +0000 (17:38 +0200)]
Jitter signatures times when adding dynamic records.
When doing regular signing expiry time is jittered to make sure
that the re-signing times are not clumped together. This expands
this behaviour to expiry times of dynamically added records.
When incrementally re-signing a zone use the full jitter range if
the server appears to have been offline for greater than 5 minutes
otherwise use a small jitter range of 3600 seconds. This will stop
the signatures becoming more clustered if the server has been off
line for a significant period of time (> 5 minutes).
Diego Fronza [Tue, 5 Nov 2019 20:48:47 +0000 (17:48 -0300)]
Added TCP high-water statistics variable
This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.
It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.
The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.
Ondřej Surý [Thu, 31 Oct 2019 11:50:58 +0000 (06:50 -0500)]
libdns: add missing checks for return values in dnstap unit test
Related scan-build report:
dnstap_test.c:169:2: warning: Value stored to 'result' is never read
result = dns_test_makeview("test", &view);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
dnstap_test.c:193:2: warning: Value stored to 'result' is never read
result = dns_compress_init(&cctx, -1, dt_mctx);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.
Ondřej Surý [Thu, 31 Oct 2019 11:46:32 +0000 (06:46 -0500)]
named: remove named_g_defaultdnstap global variable
The named_g_defaultdnstap was never used as the dnstap requires
explicit configuration of the output file.
Related scan-build report:
./server.c:3476:14: warning: Value stored to 'dpath' during its initialization is never read
const char *dpath = named_g_defaultdnstap;
^~~~~ ~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
Tony Finch [Tue, 15 Oct 2019 14:12:29 +0000 (15:12 +0100)]
Do not flush the cache for `rndc validation status`
And add a note to the man page that `rndc validation` flushes the
cache when the validation state is changed. (It is necessary to flush
the cache when turning on validation, to avoid continuing to use
cryptographically invalid data. It is probably wise to flush the cache
when turning off validation to recover from lameness problems.)
Tony Finch [Tue, 15 Oct 2019 14:06:01 +0000 (15:06 +0100)]
Include all views in output of `rndc validation status`
The implementation of `rndc validation status` iterates over all the
views to print their validation status. It takes care to print newlines
in between, but it also used put a nul byte at the end of the first view
which truncated the output.
After this change, the nul byte is added at the end so that it prints
the validation status in all views. The `_bind` view is skipped
because its validation status is irrelevant.
Michał Kępień [Thu, 31 Oct 2019 07:48:35 +0000 (08:48 +0100)]
Prevent query loops for misbehaving servers
If a TCP connection fails while attempting to send a query to a server,
the fetch context will be restarted without marking the target server as
a bad one. If this happens for a server which:
- was already marked with the DNS_FETCHOPT_EDNS512 flag,
- responds to EDNS queries with the UDP payload size set to 512 bytes,
- does not send response packets larger than 512 bytes,
and the response for the query being sent is larger than 512 byes, then
named will pointlessly alternate between sending UDP queries with EDNS
UDP payload size set to 512 bytes (which are responded to with truncated
answers) and TCP connections until the fetch context retry limit is
reached. Prevent such query loops by marking the server as bad for a
given fetch context if the advertised EDNS UDP payload size for that
server gets reduced to 512 bytes and it is impossible to reach it using
TCP.
Tony Finch [Tue, 22 Oct 2019 14:37:38 +0000 (15:37 +0100)]
Fix hang in `named-compilezone | head`
I was truncating zone files for experimental purposes when I found
that `named-compilezone | head` got stuck. The full command line that
exhibited the problem was:
This requires a large enough zone to exhibit the problem, more than
about 70000 bytes of plain text output from named-compilezone.
I was running the command on Debian Stretch amd64.
This was puzzling since it looked like something was suppressing the
SIGPIPE. I used `strace` to examine what was happening at the hang.
The program was just calling write() a lot to print the zone file, and
the last write() hanged until I sent it a SIGINT.
During some discussion with friends, Ian Jackson guessed that opening
/dev/stdout O_RDRW might be the problem, and after some tests we found
that this does in fact suppress SIGPIPE.
Since `named-compilezone` only needs to write to its output file, the
fix is to omit the stdio "+" update flag.