A different solution in the future might be adopted depending
on feedback and other new information, so it makes sense to mark
these options as EXPERIMENTAL until we have more data.
In order to protect from a malicious DNS client that sends many
queries with a SIG(0)-signed message, add a quota of simultaneously
running SIG(0) checks.
This protection can only help when named is using more than one worker
threads. For example, if named is running with the '-n 4' option, and
'sig0checks-quota 2;' is used, then named will make sure to not use
more than 2 workers for the SIG(0) signature checks in parallel, thus
leaving the other workers to serve the remaining clients which do not
use SIG(0)-signed messages.
That limitation is going to change when SIG(0) signature checks are
offloaded to "slow" threads in a future commit.
The 'sig0checks-quota-exempt' ACL option can be used to exempt certain
clients from the quota requirements using their IP or network addresses.
The 'sig0checks-quota-maxwait-ms' option is used to define a maximum
amount of time for named to wait for a quota to appear. If during that
time no new quota becomes available, named will answer to the client
with DNS_R_REFUSED.
Previously, the number of RR types for a single owner name was limited
only by the maximum number of the types (64k). As the data structure
that holds the RR types for the database node is just a linked list, and
there are places where we just walk through the whole list (again and
again), adding a large number of RR types for a single owner named with
would slow down processing of such name (database node).
Add a configurable limit to cap the number of the RR types for a single
owner. This is enforced at the database (rbtdb, qpzone, qpcache) level
and configured with new max-types-per-name configuration option that
can be configured globally, per-view and per-zone.
Previously, the number of RRs in the RRSets were internally unlimited.
As the data structure that holds the RRs is just a linked list, and
there are places where we just walk through all of the RRs, adding an
RRSet with huge number of RRs inside would slow down processing of said
RRSets.
Add a configurable limit to cap the number of the RRs in a single RRSet.
This is enforced at the database (rbtdb, qpzone, qpcache) level and
configured with new max-records-per-type configuration option that can
be configured globally, per-view and per-zone.
Instead of running all the cryptographic validation in a tight loop,
spread it out into multiple event loop "ticks", but moving every single
validation into own isc_async_run() asynchronous event. Move the
cryptographic operations - both verification and DNSKEY selection - to
the offloaded threads (isc_work_enqueue), this further limits the time
we spend doing expensive operations on the event loops that should be
fast.
Limit the impact of invalid or malicious RRSets that contain crafted
records causing the dns_validator to do many validations per single
fetch by adding a cap on the maximum number of validations and maximum
number of validation failures that can happen before the resolving
fails.
The name "uri" was considered to be too generic and could potentially
clash with a future URI configuration option. Renamed to "pkcs11-uri".
Note that this option name was also preferred over "pkcs11uri", the
dash is considered to be the more clearer form.
Add new configuration for setting key stores. The new 'key-store'
statement allows users to configure key store backends. These can be
of type 'file' (that works the same as 'key-directory') or of type
'pkcs11'. In the latter case, keys should be stored in a HSM that is
accessible through a PKCS#11 interface.
Keys configured within 'dnssec-policy' can now also use the 'key-store'
option to set a specific key store.
Update the checkconf test to accomodate for the new configuration.
Remove the CFG_CLAUSEFLAG_EXPERIMENTAL flag from the
"trust-anchor-telemetry" statement as the behavior of the latter has not
been changed since its initial implementation and there are currently no
plans to do so. This silences a relevant log message that was emitted
even when the feature was explicitly disabled.
these options control default timing of retries in the resolver
for experimental purposes; they are not known to useful in production
environments. they will be removed in the future; for now, we
only log a warning if they are used.
The main intention of PROXY protocol is to pass endpoints information
to a back-end server (in our case - BIND). That means that it is a
valid way to spoof endpoints information, as the addresses and ports
extracted from PROXYv2 headers, from the point of view of BIND, are
used instead of the real connection addresses.
Of course, an ability to easily spoof endpoints information can be
considered a security issue when used uncontrollably. To resolve that,
we introduce 'allow-proxy' and 'allow-proxy-on' ACL options. These are
the only ACL options in BIND that work with real PROXY connections
addresses, allowing a DNS server operator to specify from what clients
and on which interfaces he or she is willing to accept PROXY
headers. By default, for security reasons we do not allow to accept
them.
This commit extends "listen-on" statement with "proxy" options that
allows one to enable PROXYv2 support on a dedicated listener. It can
have the following values:
- "plain" to send PROXYv2 headers without encryption, even in the case
of encrypted transports.
- "encrypted" to send PROXYv2 headers encrypted right after the TLS
handshake.
The AES algorithm for DNS cookies was being kept for legacy reasons, and
it can be safely removed in the next major release. Remove both the AES
usage for DNS cookies and the AES implementation itself.
The lock-file configuration (both from configuration file and -X
argument to named) has better alternatives nowadays. Modern process
supervisor should be used to ensure that a single named process is
running on a given configuration.
Alternatively, it's possible to wrap the named with flock(1).
This is first step in removing the lock-file configuration option, it
marks both the `lock-file` configuration directive and -X option to
named as deprecated.
Add a configuration option, resolver-use-dns64, which when true
will cause named to map IPv4 address to IPv6 addresses using the
view's DNS64 mapping rules when making iterative queries.
The dnssec-must-be-secure feature was added in the early days of BIND 9
and DNSSEC and it makes sense only as a debugging feature.
Remove the feature to simplify the code.
these options concentrate zone maintenance actions into
bursts for the benefit of servers with intermittent connections.
that's no longer something we really need to optimize.
Add an option to enable/disable inline-signing inside the
dnssec-policy clause. The existing inline-signing option that is
set in the zone clause takes priority, but if it is omitted, then the
value that is set in dnssec-policy is taken.
The built-in policies use inline-signing.
This means that if you want to use the default policy without
inline-signing you either have to set it explicitly in the zone
clause:
zone "example" {
...
dnssec-policy default;
inline-signing no;
};
Or create a new policy, only overriding the inline-signing option:
dnssec-policy "default-dynamic" {
inline-signing no;
};
zone "example" {
...
dnssec-policy default-dynamic;
};
This also means that if you are going insecure with a dynamic zone,
the built-in "insecure" policy needs to be accompanied with
"inline-signing no;".
These two configuration options worked in conjunction with 'auto-dnssec'
to determine KSK usage, and thus are now obsoleted.
However, in the code we keep KSK processing so that when a zone is
reconfigured from using 'dnssec-policy' immediately to 'none' (without
going through 'insecure'), the zone is not immediately made bogus.
Add one more test case for going straight to none, now with a dynamic
zone (no inline-signing).
for testing purposes, we need to be able to specify a library path from
which to load the dnsrps implementation. this can now be done with the
"dnsrps-library" option.
DNSRPS can now be enabled in configure regardless of whether librpz.so
is currently installed on the system.
These options and zone type were created to address the
SiteFinder controversy, in which certain TLD's redirected queries
rather than returning NXDOMAIN. since TLD's are now DNSSEC-signed,
this is no longer likely to be a problem.
The deprecation message for 'type delegation-only' is issued from
the configuration checker rather than the parser. therefore,
isccfg_check_namedconf() has been modified to take a 'nodeprecate'
parameter to suppress the warning when named-checkconf is used with
the command-line option to ignore warnings on deprecated options (-i).
Completely remove the TKEY Mode 2 (Diffie-Hellman Exchanged Keying) from
BIND 9 (from named, named.conf and all the tools). The TKEY usage is
fringe at best and in all known cases, GSSAPI is being used as it should.
The draft-eastlake-dnsop-rfc2930bis-tkey specifies that:
4.2 Diffie-Hellman Exchanged Keying (Deprecated)
The use of this mode (#2) is NOT RECOMMENDED for the following two
reasons but the specification is still included in Appendix A in case
an implementation is needed for compatibility with old TKEY
implementations. See Section 4.6 on ECDH Exchanged Keying.
The mixing function used does not meet current cryptographic
standards because it uses MD5 [RFC6151].
RSA keys must be excessively long to achieve levels of security
required by current standards.
We might optionally implement Elliptic Curve Diffie-Hellman (ECDH) key
exchange mode 6 if the draft ever reaches the RFC status. Meanwhile the
insecure DH mode needs to be removed.
- removed documentation of -S option from named man page
- removed documentation of reserved-sockets from ARM
- simplified documentation of dnssec-secure-to-insecure - it
now just says it's obsolete rather than describing what it
doesn't do anymore
- marked three formerly obsolete options as ancient:
parent-registration-delay, reserved-sockets, and
suppress-initial-notify
the built-in trust anchors in named and delv are sufficent for
validation. named still needs to be able to load trust anchors from
a bind.keys file for testing purposes, but it doesn't need to be
the default behavior.
we now only load trust anchors from a file if explicitly specified
via the "bindkeys-file" option in named or the "-a" command line
argument to delv. documentation has been cleaned up to remove references
to /etc/bind.keys.
Closes#3850.
A 'tls' statement can be specified both for individual addresses
and for the whole list (as a default value when an individual
address doesn't have its own 'tls' set), just as it was done
before for the 'port' value.
Create a new function 'print_rawqstring()' to print a string residing
in a 'isc_textregion_t' type parameter.
Create a new function 'copy_string()' to copy a string from a
'cfg_obj_t' object into a 'isc_textregion_t'.
Deprecate the use of "port" when configuring query-source(-v6),
transfer-source(-v6), notify-source(-v6), parental-source(-v6),
etc. Also deprecate use-{v4,v6}-udp-ports and avoid-{v4,v6}udp-ports.
DSCP has not been fully working since the network manager was
introduced in 9.16, and has been completely broken since 9.18.
This seems to have caused very few difficulties for anyone,
so we have now marked it as obsolete and removed the
implementation.
To ensure that old config files don't fail, the code to parse
dscp key-value pairs is still present, but a warning is logged
that the feature is obsolete and should not be used. Nothing is
done with configured values, and there is no longer any
range checking.
Add a new way to configure the preferred source address when talking to
remote servers such as primaries and parental-agents. This will
eventually deprecate options such as 'parental-source',
'parental-source-v6', 'transfer-source', etc.
Example of the new configuration:
parental-agents "parents" port 5353 \
source 10.10.10.10 port 5354 dscp 54 \
source-v6 2001:db8::10 port 5355 dscp 55 {
10.10.10.11;
2001:db8::11;
};
After deprecating the operating system limits settings (coresize,
datasize, files and stacksize), mark them as ancient and remove the code
that sets the values from config.
It was possible to set operating system limits (RLIMIT_DATA,
RLIMIT_STACK, RLIMIT_CORE and RLIMIT_NOFILE) from named.conf. It's
better to leave these untouched as setting these is responsibility of
the operating system and/or supervisor.
Deprecate the configuration options and remove them in future BIND 9
release.
