.. Copyright (C) Internet Systems Consortium, Inc. ("ISC") .. .. SPDX-License-Identifier: MPL-2.0 .. .. This Source Code Form is subject to the terms of the Mozilla Public .. License, v. 2.0. If a copy of the MPL was not distributed with this .. file, you can obtain one at https://mozilla.org/MPL/2.0/. .. .. See the COPYRIGHT file distributed with this work for additional .. information regarding copyright ownership. Notes for BIND 9.21.7 --------------------- New Features ~~~~~~~~~~~~ - Add support for EDE 20 (Not Authoritative) Support was added for EDE codes 20 (Not Authoritative) when the client requests recursion (RD) but the server has recursion disabled. :rfc:`8914` indicates that EDE 20 should also be returned if the client does not have the RD bit set (and recursion is needed), but it does not apply for BIND; BIND would try to resolve from the "deepest" referral in the AUTHORITY section. For example, if the client asks for ``www.isc.org/A`` but the server only knows the root domain, it will return NOERROR but no answer for ``www.isc.org/A``, just the list of other servers to ask. :gl:`#1836` - Add support for EDE 7 and EDE 8. Support was added for EDE codes 7 (Signature Expired) and 8 (Signature Not Yet Valid), which might occur during DNSSEC validation. :gl:`#2715` - Add support for EDNS ZONEVERSION option. :iscman:`dig` and :iscman:`named` can now make requests with an EDNS ZONEVERSION option present. Two new :iscman:`named.conf` options have been added: :any:`request-zoneversion` and :any:`provide-zoneversion`. :any:`request-zoneversion` is ``off`` by default. :any:`provide-zoneversion` is ``on`` by default. :gl:`#4767` - :iscman:`dig` can now display the received BADVERS message during negotiation. :option:`dig +showbadvers` now displays the received BADVERS message and continues the EDNS version negotiation. Previously, to see the BADVERS message :option:`dig +noednsnegotiation` had to be specified, which terminated the EDNS negotiation. Additionally, the specified EDNS value (``+edns=value``) is now used when making all the initial queries with :option:`dig +trace`, i.e. EDNS version negotiation is performed with each server when performing the trace. :gl:`#5234` - Add an :iscman:`rndc` command to reset some statistics counters. The new :option:`rndc reset-stats` command allows some statistics counters to be reset during runtime. At the moment only two "high-water" counters are supported, so the ability to reset them after the initial peaks during the server's "warm-up" phase may be useful for some operators. :gl:`#5251` Removed Features ~~~~~~~~~~~~~~~~ - Drop readline alternatives in favor of libedit. Libedit is now ubiquitous and has a license compatible with MPL 2.0. We are now dropping readline (GPL 3.0) and editline (obsolete) support in favor of libedit. - Implement the systemd notification protocol manually to remove dependency on libsystemd. - Remove unnecessary options in :iscman:`dnssec-keygen` and :iscman:`dnssec-keyfromlabel`. The :iscman:`dnssec-keygen` utility (and :iscman:`dnssec-keyfromlabel`, which was derived from it) had several options dating to the time when keys in DNS were still experimental and not fully specified, and when :iscman:`dnssec-keygen` had the additional function of generating TSIG keys, which are now generated by :iscman:`tsig-keygen`. These options are no longer necessary in the modern DNSSEC environment, and have been removed. The removed options are: - ``-t`` (key type), which formerly set flags to disable confidentiality or authentication support in a key; these are no longer used. - ``-n`` (name type), which is now always set to "ZONE" for DNSKEY and "HOST" for KEY. - ``-p`` (protocol), which is now always set to 3 (DNSSEC); no other value has ever been defined. - ``-s`` (signatory field), which was never fully defined. - ``-d`` (digest bits), which is meaningful only for TSIG keys. Feature Changes ~~~~~~~~~~~~~~~ - When forwarding, query with CD=0 first. Previously, when queries were forwarded to a remote resolver, the CD (checking disabled) bit was used, which could lead to bogus data being retrieved that might have been corrected if validation had been permitted. The CD bit is now only used as a fallback if an initial query without CD fails. :gl:`#5132`. - Improve the LRU cache-expiration mechanism. The LRU cache-expiration mechanism has been improved to a SIEVE-LRU-based mechanism that triggers when the cache is close to the :any:`max-cache-size` limit. This improves the recursive server's performance. Bug Fixes ~~~~~~~~~ - QNAME minimization could leak the query type. When performing QNAME minimization, :iscman:`named` now sends an NS query for the original query name, before sending the final query. This prevents the parent zone from learning the original query type, in the event that the query name is a delegation point. For example, when looking up an address record for ``example.com``, NS queries are now sent to the servers for both ``com`` and ``example.com``, before the address query is sent to the servers for ``example.com``. Previously, an address query would have been sent to the servers for ``com``. :gl:`#4805` - Stop caching lack of EDNS support. :iscman:`named` could falsely learn that a server did not support EDNS when a spoofed response was received; that subsequently prevented DNSSEC lookups from being made. This has been fixed. :gl:`#3949` :gl:`#5066` - Fix resolver statistics counters for timed-out responses. When query responses timed out, the resolver could incorrectly increase the regular response counters, even if no response was received. This has been fixed. :gl:`#5193` - Nested DNS validation could cause an assertion failure. When multiple nested DNS validations were destroyed out of order, the EDE context could be freed before all EDE codes were copied, which could cause an assertion failure. This has been fixed. :gl:`#5213` - Ensure :any:`max-clients-per-query` is at least :any:`clients-per-query`. If the :any:`max-clients-per-query` option is set to a lower value than :any:`clients-per-query`, the value is adjusted to match :any:`clients-per-query`. :gl:`#5224` - Fix write after free in validator code. Raw integer pointers were being used for the validator's nvalidations and nfails values, but the memory holding them could be freed while they were still being used. Reference counted counters are now used instead. :gl:`#5239` - Don't enforce NOAUTH/NOCONF flags in DNSKEYs. All DNSKEY keys are able to authenticate. The ``DNS_KEYTYPE_NOAUTH`` (and ``DNS_KEYTYPE_NOCONF``) flags were defined for the KEY rdata type, and are not applicable to DNSKEY. Previously, however, because the DNSKEY implementation was built on top of KEY, the ``_NOAUTH`` flag prevented authentication in DNSKEYs as well. This has been corrected. :gl:`#5240` - Fix several small DNSSEC timing issues. The following small issues related to :any:`dnssec-policy` have been fixed: - In some cases the key manager inside BIND 9 would run every hour, while in other cases it would run less often. - While ``CDS`` and ``CDNSKEY`` records will be removed correctly from the zone when the corresponding ``DS`` record needs to be updated, the expected timing metadata for when this should happen was never set. - There were a couple of cases where the safety intervals were added inappropriately, delaying key rollovers longer than necessary. - Identical keys in a :any:`dnssec-policy` may have been retired inappropriately. Note that having `keys` with identical properties is discouraged in all cases. :gl:`#5242`