include $(top_srcdir)/Makefile.docs
EXTRA_DIST = \
- advanced.rst \
+ advanced.inc.rst \
build.inc.rst \
catz.inc.rst \
chapter10.rst \
chapter2.rst \
chapter3.rst \
chapter4.rst \
+ chapter5.rst \
+ chapter6.rst \
+ chapter7.rst \
configuration.inc.rst \
conf.py \
dlz.inc.rst \
reference.rst \
requirements.inc.rst \
requirements.txt \
- security.rst \
+ security.inc.rst \
+ sig0.inc.rst \
+ tkey.inc.rst \
troubleshooting.rst \
+ tsig.inc.rst \
../dnssec-guide \
../misc/acl.grammar.rst \
../misc/controls.grammar.rst \
--- /dev/null
+.. 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.
+
+.. _advanced:
+
+Advanced Configurations
+=======================
+
+.. _dynamic_update:
+
+Dynamic Update
+--------------
+
+Dynamic update is a method for adding, replacing, or deleting records in
+a primary server by sending it a special form of DNS messages. The format
+and meaning of these messages is specified in :rfc:`2136`.
+
+Dynamic update is enabled by including an ``allow-update`` or an
+``update-policy`` clause in the ``zone`` statement.
+
+If the zone's ``update-policy`` is set to ``local``, updates to the zone
+are permitted for the key ``local-ddns``, which is generated by
+:iscman:`named` at startup. See :ref:`dynamic_update_policies` for more details.
+
+Dynamic updates using Kerberos-signed requests can be made using the
+TKEY/GSS protocol, either by setting the ``tkey-gssapi-keytab`` option
+or by setting both the ``tkey-gssapi-credential`` and
+``tkey-domain`` options. Once enabled, Kerberos-signed requests are
+matched against the update policies for the zone, using the Kerberos
+principal as the signer for the request.
+
+Updating of secure zones (zones using DNSSEC) follows :rfc:`3007`: RRSIG,
+NSEC, and NSEC3 records affected by updates are automatically regenerated
+by the server using an online zone key. Update authorization is based on
+transaction signatures and an explicit server policy.
+
+.. _journal:
+
+The Journal File
+~~~~~~~~~~~~~~~~
+
+All changes made to a zone using dynamic update are stored in the zone's
+journal file. This file is automatically created by the server when the
+first dynamic update takes place. The name of the journal file is formed
+by appending the extension ``.jnl`` to the name of the corresponding
+zone file unless specifically overridden. The journal file is in a
+binary format and should not be edited manually.
+
+The server also occasionally writes ("dumps") the complete contents
+of the updated zone to its zone file. This is not done immediately after
+each dynamic update because that would be too slow when a large zone is
+updated frequently. Instead, the dump is delayed by up to 15 minutes,
+allowing additional updates to take place. During the dump process,
+transient files are created with the extensions ``.jnw`` and
+``.jbk``; under ordinary circumstances, these are removed when the
+dump is complete, and can be safely ignored.
+
+When a server is restarted after a shutdown or crash, it replays the
+journal file to incorporate into the zone any updates that took place
+after the last zone dump.
+
+Changes that result from incoming incremental zone transfers are also
+journaled in a similar way.
+
+The zone files of dynamic zones cannot normally be edited by hand
+because they are not guaranteed to contain the most recent dynamic
+changes; those are only in the journal file. The only way to ensure
+that the zone file of a dynamic zone is up-to-date is to run
+:option:`rndc stop`.
+
+To make changes to a dynamic zone manually, follow these steps:
+first, disable dynamic updates to the zone using
+:option:`rndc freeze zone <rndc freeze>`. This updates the zone file with the
+changes stored in its ``.jnl`` file. Then, edit the zone file. Finally, run
+:option:`rndc thaw zone <rndc thaw>` to reload the changed zone and re-enable dynamic
+updates.
+
+:option:`rndc sync zone <rndc sync>` updates the zone file with changes from the
+journal file without stopping dynamic updates; this may be useful for
+viewing the current zone state. To remove the ``.jnl`` file after
+updating the zone file, use :option:`rndc sync -clean <rndc sync>`.
+
+.. _incremental_zone_transfers:
+
+Incremental Zone Transfers (IXFR)
+---------------------------------
+
+The incremental zone transfer (IXFR) protocol is a way for secondary servers
+to transfer only changed data, instead of having to transfer an entire
+zone. The IXFR protocol is specified in :rfc:`1995`.
+
+When acting as a primary server, BIND 9 supports IXFR for those zones where the
+necessary change history information is available. These include primary
+zones maintained by dynamic update and secondary zones whose data was
+obtained by IXFR. For manually maintained primary zones, and for secondary
+zones obtained by performing a full zone transfer (AXFR), IXFR is
+supported only if the option ``ixfr-from-differences`` is set to
+``yes``.
+
+When acting as a secondary server, BIND 9 attempts to use IXFR unless it is
+explicitly disabled. For more information about disabling IXFR, see the
+description of the ``request-ixfr`` clause of the ``server`` statement.
+
+When a secondary server receives a zone via AXFR, it creates a new copy of the
+zone database and then swaps it into place; during the loading process, queries
+continue to be served from the old database with no interference. When receiving
+a zone via IXFR, however, changes are applied to the running zone, which may
+degrade query performance during the transfer. If a server receiving an IXFR
+request determines that the response size would be similar in size to an AXFR
+response, it may wish to send AXFR instead. The threshold at which this
+determination is made can be configured using the
+``max-ixfr-ratio`` option.
+
+.. _split_dns:
+
+Split DNS
+---------
+
+Setting up different views of the DNS space to internal
+and external resolvers is usually referred to as a *split DNS* setup.
+There are several reasons an organization might want to set up its DNS
+this way.
+
+One common reason to use split DNS is to hide
+"internal" DNS information from "external" clients on the Internet.
+There is some debate as to whether this is actually useful.
+Internal DNS information leaks out in many ways (via email headers, for
+example) and most savvy "attackers" can find the information they need
+using other means. However, since listing addresses of internal servers
+that external clients cannot possibly reach can result in connection
+delays and other annoyances, an organization may choose to use split
+DNS to present a consistent view of itself to the outside world.
+
+Another common reason for setting up a split DNS system is to allow
+internal networks that are behind filters or in :rfc:`1918` space (reserved
+IP space, as documented in :rfc:`1918`) to resolve DNS on the Internet.
+Split DNS can also be used to allow mail from outside back into the
+internal network.
+
+.. _split_dns_sample:
+
+Example Split DNS Setup
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Let's say a company named *Example, Inc.* (``example.com``) has several
+corporate sites that have an internal network with reserved Internet
+Protocol (IP) space and an external demilitarized zone (DMZ), or
+"outside" section of a network, that is available to the public.
+
+Example, Inc. wants its internal clients to be able to resolve
+external hostnames and to exchange mail with people on the outside. The
+company also wants its internal resolvers to have access to certain
+internal-only zones that are not available at all outside of the
+internal network.
+
+To accomplish this, the company sets up two sets of name
+servers. One set is on the inside network (in the reserved IP
+space) and the other set is on bastion hosts, which are "proxy"
+hosts in the DMZ that can talk to both sides of its network.
+
+The internal servers are configured to forward all queries, except
+queries for ``site1.internal``, ``site2.internal``,
+``site1.example.com``, and ``site2.example.com``, to the servers in the
+DMZ. These internal servers have complete sets of information for
+``site1.example.com``, ``site2.example.com``, ``site1.internal``, and
+``site2.internal``.
+
+To protect the ``site1.internal`` and ``site2.internal`` domains, the
+internal name servers must be configured to disallow all queries to
+these domains from any external hosts, including the bastion hosts.
+
+The external servers, which are on the bastion hosts, are configured
+to serve the "public" version of the ``site1.example.com`` and ``site2.example.com``
+zones. This could include things such as the host records for public
+servers (``www.example.com`` and ``ftp.example.com``) and mail exchange
+(MX) records (``a.mx.example.com`` and ``b.mx.example.com``).
+
+In addition, the public ``site1.example.com`` and ``site2.example.com`` zones should
+have special MX records that contain wildcard (``*``) records pointing to
+the bastion hosts. This is needed because external mail servers
+have no other way of determining how to deliver mail to those internal
+hosts. With the wildcard records, the mail is delivered to the
+bastion host, which can then forward it on to internal hosts.
+
+Here's an example of a wildcard MX record:
+
+::
+
+ * IN MX 10 external1.example.com.
+
+Now that they accept mail on behalf of anything in the internal network,
+the bastion hosts need to know how to deliver mail to internal
+hosts. The resolvers on the bastion
+hosts need to be configured to point to the internal name servers
+for DNS resolution.
+
+Queries for internal hostnames are answered by the internal servers,
+and queries for external hostnames are forwarded back out to the DNS
+servers on the bastion hosts.
+
+For all of this to work properly, internal clients need to be
+configured to query *only* the internal name servers for DNS queries.
+This could also be enforced via selective filtering on the network.
+
+If everything has been set properly, Example, Inc.'s internal clients
+are now able to:
+
+- Look up any hostnames in the ``site1.example.com`` and ``site2.example.com``
+ zones.
+
+- Look up any hostnames in the ``site1.internal`` and
+ ``site2.internal`` domains.
+
+- Look up any hostnames on the Internet.
+
+- Exchange mail with both internal and external users.
+
+Hosts on the Internet are able to:
+
+- Look up any hostnames in the ``site1.example.com`` and ``site2.example.com``
+ zones.
+
+- Exchange mail with anyone in the ``site1.example.com`` and ``site2.example.com``
+ zones.
+
+Here is an example configuration for the setup just described above.
+Note that this is only configuration information; for information on how
+to configure the zone files, see :ref:`sample_configuration`.
+
+Internal DNS server config:
+
+::
+
+
+ acl internals { 172.16.72.0/24; 192.168.1.0/24; };
+
+ acl externals { bastion-ips-go-here; };
+
+ options {
+ ...
+ ...
+ forward only;
+ // forward to external servers
+ forwarders {
+ bastion-ips-go-here;
+ };
+ // sample allow-transfer (no one)
+ allow-transfer { none; };
+ // restrict query access
+ allow-query { internals; externals; };
+ // restrict recursion
+ allow-recursion { internals; };
+ ...
+ ...
+ };
+
+ // sample primary zone
+ zone "site1.example.com" {
+ type primary;
+ file "m/site1.example.com";
+ // do normal iterative resolution (do not forward)
+ forwarders { };
+ allow-query { internals; externals; };
+ allow-transfer { internals; };
+ };
+
+ // sample secondary zone
+ zone "site2.example.com" {
+ type secondary;
+ file "s/site2.example.com";
+ primaries { 172.16.72.3; };
+ forwarders { };
+ allow-query { internals; externals; };
+ allow-transfer { internals; };
+ };
+
+ zone "site1.internal" {
+ type primary;
+ file "m/site1.internal";
+ forwarders { };
+ allow-query { internals; };
+ allow-transfer { internals; }
+ };
+
+ zone "site2.internal" {
+ type secondary;
+ file "s/site2.internal";
+ primaries { 172.16.72.3; };
+ forwarders { };
+ allow-query { internals };
+ allow-transfer { internals; }
+ };
+
+External (bastion host) DNS server configuration:
+
+::
+
+ acl internals { 172.16.72.0/24; 192.168.1.0/24; };
+
+ acl externals { bastion-ips-go-here; };
+
+ options {
+ ...
+ ...
+ // sample allow-transfer (no one)
+ allow-transfer { none; };
+ // default query access
+ allow-query { any; };
+ // restrict cache access
+ allow-query-cache { internals; externals; };
+ // restrict recursion
+ allow-recursion { internals; externals; };
+ ...
+ ...
+ };
+
+ // sample secondary zone
+ zone "site1.example.com" {
+ type primary;
+ file "m/site1.foo.com";
+ allow-transfer { internals; externals; };
+ };
+
+ zone "site2.example.com" {
+ type secondary;
+ file "s/site2.foo.com";
+ primaries { another_bastion_host_maybe; };
+ allow-transfer { internals; externals; }
+ };
+
+In the ``resolv.conf`` (or equivalent) on the bastion host(s):
+
+::
+
+ search ...
+ nameserver 172.16.72.2
+ nameserver 172.16.72.3
+ nameserver 172.16.72.4
+
+.. _ipv6:
+
+IPv6 Support in BIND 9
+----------------------
+
+BIND 9 fully supports all currently defined forms of IPv6 name-to-address
+and address-to-name lookups. It also uses IPv6 addresses to
+make queries when running on an IPv6-capable system.
+
+For forward lookups, BIND 9 supports only AAAA records. :rfc:`3363`
+deprecated the use of A6 records, and client-side support for A6 records
+was accordingly removed from BIND 9. However, authoritative BIND 9 name
+servers still load zone files containing A6 records correctly, answer
+queries for A6 records, and accept zone transfer for a zone containing
+A6 records.
+
+For IPv6 reverse lookups, BIND 9 supports the traditional "nibble"
+format used in the ``ip6.arpa`` domain, as well as the older, deprecated
+``ip6.int`` domain. Older versions of BIND 9 supported the "binary label"
+(also known as "bitstring") format, but support of binary labels has
+been completely removed per :rfc:`3363`. Many applications in BIND 9 do not
+understand the binary label format at all anymore, and return an
+error if one is given. In particular, an authoritative BIND 9 name server will
+not load a zone file containing binary labels.
+
+Address Lookups Using AAAA Records
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The IPv6 AAAA record is a parallel to the IPv4 A record, and, unlike the
+deprecated A6 record, specifies the entire IPv6 address in a single
+record. For example:
+
+::
+
+ $ORIGIN example.com.
+ host 3600 IN AAAA 2001:db8::1
+
+Use of IPv4-in-IPv6 mapped addresses is not recommended. If a host has
+an IPv4 address, use an A record, not a AAAA, with
+``::ffff:192.168.42.1`` as the address.
+
+Address-to-Name Lookups Using Nibble Format
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When looking up an address in nibble format, the address components are
+simply reversed, just as in IPv4, and ``ip6.arpa.`` is appended to the
+resulting name. For example, the following commands produce a reverse name
+lookup for a host with address ``2001:db8::1``:
+
+::
+
+ $ORIGIN 0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.
+ 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 14400 IN PTR (
+ host.example.com. )
+++ /dev/null
-.. 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.
-
-.. Advanced:
-
-Advanced DNS Features
-=====================
-
-.. _notify:
-
-Notify
-------
-
-DNS NOTIFY is a mechanism that allows primary servers to notify their
-secondary servers of changes to a zone's data. In response to a ``NOTIFY``
-from a primary server, the secondary checks to see that its version of
-the zone is the current version and, if not, initiates a zone transfer.
-
-For more information about DNS ``NOTIFY``, see the description of the
-``notify`` option in :ref:`boolean_options` and the
-description of the zone option ``also-notify`` in :ref:`zone_transfers`.
-The ``NOTIFY`` protocol is specified in :rfc:`1996`.
-
-.. note::
-
- As a secondary zone can also be a primary to other secondaries, :iscman:`named`, by
- default, sends ``NOTIFY`` messages for every zone it loads.
- Specifying ``notify primary-only;`` causes :iscman:`named` to only send
- ``NOTIFY`` for primary zones that it loads.
-
-.. _dynamic_update:
-
-Dynamic Update
---------------
-
-Dynamic update is a method for adding, replacing, or deleting records in
-a primary server by sending it a special form of DNS messages. The format
-and meaning of these messages is specified in :rfc:`2136`.
-
-Dynamic update is enabled by including an ``allow-update`` or an
-``update-policy`` clause in the ``zone`` statement.
-
-If the zone's ``update-policy`` is set to ``local``, updates to the zone
-are permitted for the key ``local-ddns``, which is generated by
-:iscman:`named` at startup. See :ref:`dynamic_update_policies` for more details.
-
-Dynamic updates using Kerberos-signed requests can be made using the
-TKEY/GSS protocol, either by setting the ``tkey-gssapi-keytab`` option
-or by setting both the ``tkey-gssapi-credential`` and
-``tkey-domain`` options. Once enabled, Kerberos-signed requests are
-matched against the update policies for the zone, using the Kerberos
-principal as the signer for the request.
-
-Updating of secure zones (zones using DNSSEC) follows :rfc:`3007`: RRSIG,
-NSEC, and NSEC3 records affected by updates are automatically regenerated
-by the server using an online zone key. Update authorization is based on
-transaction signatures and an explicit server policy.
-
-.. _journal:
-
-The Journal File
-~~~~~~~~~~~~~~~~
-
-All changes made to a zone using dynamic update are stored in the zone's
-journal file. This file is automatically created by the server when the
-first dynamic update takes place. The name of the journal file is formed
-by appending the extension ``.jnl`` to the name of the corresponding
-zone file unless specifically overridden. The journal file is in a
-binary format and should not be edited manually.
-
-The server also occasionally writes ("dumps") the complete contents
-of the updated zone to its zone file. This is not done immediately after
-each dynamic update because that would be too slow when a large zone is
-updated frequently. Instead, the dump is delayed by up to 15 minutes,
-allowing additional updates to take place. During the dump process,
-transient files are created with the extensions ``.jnw`` and
-``.jbk``; under ordinary circumstances, these are removed when the
-dump is complete, and can be safely ignored.
-
-When a server is restarted after a shutdown or crash, it replays the
-journal file to incorporate into the zone any updates that took place
-after the last zone dump.
-
-Changes that result from incoming incremental zone transfers are also
-journaled in a similar way.
-
-The zone files of dynamic zones cannot normally be edited by hand
-because they are not guaranteed to contain the most recent dynamic
-changes; those are only in the journal file. The only way to ensure
-that the zone file of a dynamic zone is up-to-date is to run
-:option:`rndc stop`.
-
-To make changes to a dynamic zone manually, follow these steps:
-first, disable dynamic updates to the zone using
-:option:`rndc freeze zone <rndc freeze>`. This updates the zone file with the
-changes stored in its ``.jnl`` file. Then, edit the zone file. Finally, run
-:option:`rndc thaw zone <rndc thaw>` to reload the changed zone and re-enable dynamic
-updates.
-
-:option:`rndc sync zone <rndc sync>` updates the zone file with changes from the
-journal file without stopping dynamic updates; this may be useful for
-viewing the current zone state. To remove the ``.jnl`` file after
-updating the zone file, use :option:`rndc sync -clean <rndc sync>`.
-
-.. _incremental_zone_transfers:
-
-Incremental Zone Transfers (IXFR)
----------------------------------
-
-The incremental zone transfer (IXFR) protocol is a way for secondary servers
-to transfer only changed data, instead of having to transfer an entire
-zone. The IXFR protocol is specified in :rfc:`1995`.
-
-When acting as a primary server, BIND 9 supports IXFR for those zones where the
-necessary change history information is available. These include primary
-zones maintained by dynamic update and secondary zones whose data was
-obtained by IXFR. For manually maintained primary zones, and for secondary
-zones obtained by performing a full zone transfer (AXFR), IXFR is
-supported only if the option ``ixfr-from-differences`` is set to
-``yes``.
-
-When acting as a secondary server, BIND 9 attempts to use IXFR unless it is
-explicitly disabled. For more information about disabling IXFR, see the
-description of the ``request-ixfr`` clause of the ``server`` statement.
-
-When a secondary server receives a zone via AXFR, it creates a new copy of the
-zone database and then swaps it into place; during the loading process, queries
-continue to be served from the old database with no interference. When receiving
-a zone via IXFR, however, changes are applied to the running zone, which may
-degrade query performance during the transfer. If a server receiving an IXFR
-request determines that the response size would be similar in size to an AXFR
-response, it may wish to send AXFR instead. The threshold at which this
-determination is made can be configured using the
-``max-ixfr-ratio`` option.
-
-.. _split_dns:
-
-Split DNS
----------
-
-Setting up different views of the DNS space to internal
-and external resolvers is usually referred to as a *split DNS* setup.
-There are several reasons an organization might want to set up its DNS
-this way.
-
-One common reason to use split DNS is to hide
-"internal" DNS information from "external" clients on the Internet.
-There is some debate as to whether this is actually useful.
-Internal DNS information leaks out in many ways (via email headers, for
-example) and most savvy "attackers" can find the information they need
-using other means. However, since listing addresses of internal servers
-that external clients cannot possibly reach can result in connection
-delays and other annoyances, an organization may choose to use split
-DNS to present a consistent view of itself to the outside world.
-
-Another common reason for setting up a split DNS system is to allow
-internal networks that are behind filters or in :rfc:`1918` space (reserved
-IP space, as documented in :rfc:`1918`) to resolve DNS on the Internet.
-Split DNS can also be used to allow mail from outside back into the
-internal network.
-
-.. _split_dns_sample:
-
-Example Split DNS Setup
-~~~~~~~~~~~~~~~~~~~~~~~
-
-Let's say a company named *Example, Inc.* (``example.com``) has several
-corporate sites that have an internal network with reserved Internet
-Protocol (IP) space and an external demilitarized zone (DMZ), or
-"outside" section of a network, that is available to the public.
-
-Example, Inc. wants its internal clients to be able to resolve
-external hostnames and to exchange mail with people on the outside. The
-company also wants its internal resolvers to have access to certain
-internal-only zones that are not available at all outside of the
-internal network.
-
-To accomplish this, the company sets up two sets of name
-servers. One set is on the inside network (in the reserved IP
-space) and the other set is on bastion hosts, which are "proxy"
-hosts in the DMZ that can talk to both sides of its network.
-
-The internal servers are configured to forward all queries, except
-queries for ``site1.internal``, ``site2.internal``,
-``site1.example.com``, and ``site2.example.com``, to the servers in the
-DMZ. These internal servers have complete sets of information for
-``site1.example.com``, ``site2.example.com``, ``site1.internal``, and
-``site2.internal``.
-
-To protect the ``site1.internal`` and ``site2.internal`` domains, the
-internal name servers must be configured to disallow all queries to
-these domains from any external hosts, including the bastion hosts.
-
-The external servers, which are on the bastion hosts, are configured
-to serve the "public" version of the ``site1.example.com`` and ``site2.example.com``
-zones. This could include things such as the host records for public
-servers (``www.example.com`` and ``ftp.example.com``) and mail exchange
-(MX) records (``a.mx.example.com`` and ``b.mx.example.com``).
-
-In addition, the public ``site1.example.com`` and ``site2.example.com`` zones should
-have special MX records that contain wildcard (``*``) records pointing to
-the bastion hosts. This is needed because external mail servers
-have no other way of determining how to deliver mail to those internal
-hosts. With the wildcard records, the mail is delivered to the
-bastion host, which can then forward it on to internal hosts.
-
-Here's an example of a wildcard MX record:
-
-::
-
- * IN MX 10 external1.example.com.
-
-Now that they accept mail on behalf of anything in the internal network,
-the bastion hosts need to know how to deliver mail to internal
-hosts. The resolvers on the bastion
-hosts need to be configured to point to the internal name servers
-for DNS resolution.
-
-Queries for internal hostnames are answered by the internal servers,
-and queries for external hostnames are forwarded back out to the DNS
-servers on the bastion hosts.
-
-For all of this to work properly, internal clients need to be
-configured to query *only* the internal name servers for DNS queries.
-This could also be enforced via selective filtering on the network.
-
-If everything has been set properly, Example, Inc.'s internal clients
-are now able to:
-
-- Look up any hostnames in the ``site1.example.com`` and ``site2.example.com``
- zones.
-
-- Look up any hostnames in the ``site1.internal`` and
- ``site2.internal`` domains.
-
-- Look up any hostnames on the Internet.
-
-- Exchange mail with both internal and external users.
-
-Hosts on the Internet are able to:
-
-- Look up any hostnames in the ``site1.example.com`` and ``site2.example.com``
- zones.
-
-- Exchange mail with anyone in the ``site1.example.com`` and ``site2.example.com``
- zones.
-
-Here is an example configuration for the setup just described above.
-Note that this is only configuration information; for information on how
-to configure the zone files, see :ref:`sample_configuration`.
-
-Internal DNS server config:
-
-::
-
-
- acl internals { 172.16.72.0/24; 192.168.1.0/24; };
-
- acl externals { bastion-ips-go-here; };
-
- options {
- ...
- ...
- forward only;
- // forward to external servers
- forwarders {
- bastion-ips-go-here;
- };
- // sample allow-transfer (no one)
- allow-transfer { none; };
- // restrict query access
- allow-query { internals; externals; };
- // restrict recursion
- allow-recursion { internals; };
- ...
- ...
- };
-
- // sample primary zone
- zone "site1.example.com" {
- type primary;
- file "m/site1.example.com";
- // do normal iterative resolution (do not forward)
- forwarders { };
- allow-query { internals; externals; };
- allow-transfer { internals; };
- };
-
- // sample secondary zone
- zone "site2.example.com" {
- type secondary;
- file "s/site2.example.com";
- primaries { 172.16.72.3; };
- forwarders { };
- allow-query { internals; externals; };
- allow-transfer { internals; };
- };
-
- zone "site1.internal" {
- type primary;
- file "m/site1.internal";
- forwarders { };
- allow-query { internals; };
- allow-transfer { internals; }
- };
-
- zone "site2.internal" {
- type secondary;
- file "s/site2.internal";
- primaries { 172.16.72.3; };
- forwarders { };
- allow-query { internals };
- allow-transfer { internals; }
- };
-
-External (bastion host) DNS server configuration:
-
-::
-
- acl internals { 172.16.72.0/24; 192.168.1.0/24; };
-
- acl externals { bastion-ips-go-here; };
-
- options {
- ...
- ...
- // sample allow-transfer (no one)
- allow-transfer { none; };
- // default query access
- allow-query { any; };
- // restrict cache access
- allow-query-cache { internals; externals; };
- // restrict recursion
- allow-recursion { internals; externals; };
- ...
- ...
- };
-
- // sample secondary zone
- zone "site1.example.com" {
- type primary;
- file "m/site1.foo.com";
- allow-transfer { internals; externals; };
- };
-
- zone "site2.example.com" {
- type secondary;
- file "s/site2.foo.com";
- primaries { another_bastion_host_maybe; };
- allow-transfer { internals; externals; }
- };
-
-In the ``resolv.conf`` (or equivalent) on the bastion host(s):
-
-::
-
- search ...
- nameserver 172.16.72.2
- nameserver 172.16.72.3
- nameserver 172.16.72.4
-
-.. _tsig:
-
-TSIG
-----
-
-TSIG (Transaction SIGnatures) is a mechanism for authenticating DNS
-messages, originally specified in :rfc:`2845`. It allows DNS messages to be
-cryptographically signed using a shared secret. TSIG can be used in any
-DNS transaction, as a way to restrict access to certain server functions
-(e.g., recursive queries) to authorized clients when IP-based access
-control is insufficient or needs to be overridden, or as a way to ensure
-message authenticity when it is critical to the integrity of the server,
-such as with dynamic UPDATE messages or zone transfers from a primary to
-a secondary server.
-
-This section is a guide to setting up TSIG in BIND. It describes the
-configuration syntax and the process of creating TSIG keys.
-
-:iscman:`named` supports TSIG for server-to-server communication, and some of
-the tools included with BIND support it for sending messages to
-:iscman:`named`:
-
- * :ref:`man_nsupdate` supports TSIG via the :option:`-k <nsupdate -k>`, :option:`-l <nsupdate -l>`, and :option:`-y <nsupdate -y>` command-line options, or via the ``key`` command when running interactively.
- * :ref:`man_dig` supports TSIG via the :option:`-k <dig -k>` and :option:`-y <dig -y>` command-line options.
-
-Generating a Shared Key
-~~~~~~~~~~~~~~~~~~~~~~~
-
-TSIG keys can be generated using the :iscman:`tsig-keygen` command; the output
-of the command is a ``key`` directive suitable for inclusion in
-:iscman:`named.conf`. The key name, algorithm, and size can be specified by
-command-line parameters; the defaults are "tsig-key", HMAC-SHA256, and
-256 bits, respectively.
-
-Any string which is a valid DNS name can be used as a key name. For
-example, a key to be shared between servers called ``host1`` and ``host2``
-could be called "host1-host2.", and this key can be generated using:
-
-::
-
- $ tsig-keygen host1-host2. > host1-host2.key
-
-This key may then be copied to both hosts. The key name and secret must
-be identical on both hosts. (Note: copying a shared secret from one
-server to another is beyond the scope of the DNS. A secure transport
-mechanism should be used: secure FTP, SSL, ssh, telephone, encrypted
-email, etc.)
-
-:iscman:`tsig-keygen` can also be run as :iscman:`ddns-confgen`, in which case its
-output includes additional configuration text for setting up dynamic DNS
-in :iscman:`named`. See :ref:`man_ddns-confgen` for details.
-
-Loading a New Key
-~~~~~~~~~~~~~~~~~
-
-For a key shared between servers called ``host1`` and ``host2``, the
-following could be added to each server's :iscman:`named.conf` file:
-
-::
-
- key "host1-host2." {
- algorithm hmac-sha256;
- secret "DAopyf1mhCbFVZw7pgmNPBoLUq8wEUT7UuPoLENP2HY=";
- };
-
-(This is the same key generated above using :iscman:`tsig-keygen`.)
-
-Since this text contains a secret, it is recommended that either
-:iscman:`named.conf` not be world-readable, or that the ``key`` directive be
-stored in a file which is not world-readable and which is included in
-:iscman:`named.conf` via the ``include`` directive.
-
-Once a key has been added to :iscman:`named.conf` and the server has been
-restarted or reconfigured, the server can recognize the key. If the
-server receives a message signed by the key, it is able to verify
-the signature. If the signature is valid, the response is signed
-using the same key.
-
-TSIG keys that are known to a server can be listed using the command
-:option:`rndc tsig-list`.
-
-Instructing the Server to Use a Key
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-A server sending a request to another server must be told whether to use
-a key, and if so, which key to use.
-
-For example, a key may be specified for each server in the ``primaries``
-statement in the definition of a secondary zone; in this case, all SOA QUERY
-messages, NOTIFY messages, and zone transfer requests (AXFR or IXFR)
-are signed using the specified key. Keys may also be specified in
-the ``also-notify`` statement of a primary or secondary zone, causing NOTIFY
-messages to be signed using the specified key.
-
-Keys can also be specified in a ``server`` directive. Adding the
-following on ``host1``, if the IP address of ``host2`` is 10.1.2.3, would
-cause *all* requests from ``host1`` to ``host2``, including normal DNS
-queries, to be signed using the ``host1-host2.`` key:
-
-::
-
- server 10.1.2.3 {
- keys { host1-host2. ;};
- };
-
-Multiple keys may be present in the ``keys`` statement, but only the
-first one is used. As this directive does not contain secrets, it can be
-used in a world-readable file.
-
-Requests sent by ``host2`` to ``host1`` would *not* be signed, unless a
-similar ``server`` directive were in ``host2``'s configuration file.
-
-When any server sends a TSIG-signed DNS request, it expects the
-response to be signed with the same key. If a response is not signed, or
-if the signature is not valid, the response is rejected.
-
-TSIG-Based Access Control
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-TSIG keys may be specified in ACL definitions and ACL directives such as
-``allow-query``, ``allow-transfer``, and ``allow-update``. The above key
-would be denoted in an ACL element as ``key host1-host2.``
-
-Here is an example of an ``allow-update`` directive using a TSIG key:
-
-::
-
- allow-update { !{ !localnets; any; }; key host1-host2. ;};
-
-This allows dynamic updates to succeed only if the UPDATE request comes
-from an address in ``localnets``, *and* if it is signed using the
-``host1-host2.`` key.
-
-See :ref:`dynamic_update_policies` for a
-discussion of the more flexible ``update-policy`` statement.
-
-Errors
-~~~~~~
-
-Processing of TSIG-signed messages can result in several errors:
-
-- If a TSIG-aware server receives a message signed by an unknown key,
- the response will be unsigned, with the TSIG extended error code set
- to BADKEY.
-- If a TSIG-aware server receives a message from a known key but with
- an invalid signature, the response will be unsigned, with the TSIG
- extended error code set to BADSIG.
-- If a TSIG-aware server receives a message with a time outside of the
- allowed range, the response will be signed but the TSIG extended
- error code set to BADTIME, and the time values will be adjusted so
- that the response can be successfully verified.
-
-In all of the above cases, the server returns a response code of
-NOTAUTH (not authenticated).
-
-TKEY
-----
-
-TKEY (Transaction KEY) is a mechanism for automatically negotiating a
-shared secret between two hosts, originally specified in :rfc:`2930`.
-
-There are several TKEY "modes" that specify how a key is to be generated
-or assigned. BIND 9 implements only one of these modes: Diffie-Hellman
-key exchange. Both hosts are required to have a KEY record with
-algorithm DH (though this record is not required to be present in a
-zone).
-
-The TKEY process is initiated by a client or server by sending a query
-of type TKEY to a TKEY-aware server. The query must include an
-appropriate KEY record in the additional section, and must be signed
-using either TSIG or SIG(0) with a previously established key. The
-server's response, if successful, contains a TKEY record in its
-answer section. After this transaction, both participants have
-enough information to calculate a shared secret using Diffie-Hellman key
-exchange. The shared secret can then be used to sign subsequent
-transactions between the two servers.
-
-TSIG keys known by the server, including TKEY-negotiated keys, can be
-listed using :option:`rndc tsig-list`.
-
-TKEY-negotiated keys can be deleted from a server using
-:option:`rndc tsig-delete`. This can also be done via the TKEY protocol
-itself, by sending an authenticated TKEY query specifying the "key
-deletion" mode.
-
-SIG(0)
-------
-
-BIND partially supports DNSSEC SIG(0) transaction signatures as
-specified in :rfc:`2535` and :rfc:`2931`. SIG(0) uses public/private keys to
-authenticate messages. Access control is performed in the same manner as with
-TSIG keys; privileges can be granted or denied in ACL directives based
-on the key name.
-
-When a SIG(0) signed message is received, it is only verified if
-the key is known and trusted by the server. The server does not attempt
-to recursively fetch or validate the key.
-
-SIG(0) signing of multiple-message TCP streams is not supported.
-
-The only tool shipped with BIND 9 that generates SIG(0) signed messages
-is :iscman:`nsupdate`.
-
-.. _DNSSEC:
-
-DNSSEC
-------
-
-Cryptographic authentication of DNS information is possible through the
-DNS Security ("DNSSEC-bis") extensions, defined in :rfc:`4033`, :rfc:`4034`,
-and :rfc:`4035`. This section describes the creation and use of DNSSEC
-signed zones.
-
-In order to set up a DNSSEC secure zone, there are a series of steps
-which must be followed. BIND 9 ships with several tools that are used in
-this process, which are explained in more detail below. In all cases,
-the ``-h`` option prints a full list of parameters. Note that the DNSSEC
-tools require the keyset files to be in the working directory or the
-directory specified by the ``-d`` option.
-
-There must also be communication with the administrators of the parent
-and/or child zone to transmit keys. A zone's security status must be
-indicated by the parent zone for a DNSSEC-capable resolver to trust its
-data. This is done through the presence or absence of a ``DS`` record at
-the delegation point.
-
-For other servers to trust data in this zone, they must be
-statically configured with either this zone's zone key or the zone key of
-another zone above this one in the DNS tree.
-
-.. _generating_dnssec_keys:
-
-Generating Keys
-~~~~~~~~~~~~~~~
-
-The :iscman:`dnssec-keygen` program is used to generate keys.
-
-A secure zone must contain one or more zone keys. The zone keys
-sign all other records in the zone, as well as the zone keys of any
-secure delegated zones. Zone keys must have the same name as the zone, have a
-name type of ``ZONE``, and be usable for authentication. It is
-recommended that zone keys use a cryptographic algorithm designated as
-"mandatory to implement" by the IETF. Currently there are two algorithms,
-RSASHA256 and ECDSAP256SHA256; ECDSAP256SHA256 is recommended for
-current and future deployments.
-
-The following command generates an ECDSAP256SHA256 key for the
-``child.example`` zone:
-
-``dnssec-keygen -a ECDSAP256SHA256 -n ZONE child.example.``
-
-Two output files are produced: ``Kchild.example.+013+12345.key`` and
-``Kchild.example.+013+12345.private`` (where 12345 is an example of a
-key tag). The key filenames contain the key name (``child.example.``),
-the algorithm (5 is RSASHA1, 8 is RSASHA256, 13 is ECDSAP256SHA256, 15 is
-ED25519, etc.), and the key tag (12345 in this case). The private key (in
-the ``.private`` file) is used to generate signatures, and the public
-key (in the ``.key`` file) is used for signature verification.
-
-To generate another key with the same properties but with a different
-key tag, repeat the above command.
-
-The :iscman:`dnssec-keyfromlabel` program is used to get a key pair from a
-crypto hardware device and build the key files. Its usage is similar to
-:iscman:`dnssec-keygen`.
-
-The public keys should be inserted into the zone file by including the
-``.key`` files using ``$INCLUDE`` statements.
-
-.. _dnssec_zone_signing:
-
-Signing the Zone
-~~~~~~~~~~~~~~~~
-
-The :iscman:`dnssec-signzone` program is used to sign a zone.
-
-Any ``keyset`` files corresponding to secure sub-zones should be
-present. The zone signer generates ``NSEC``, ``NSEC3``, and ``RRSIG``
-records for the zone, as well as ``DS`` for the child zones if :option:`-g <dnssec-signzone -g>`
-is specified. If :option:`-g <dnssec-signzone -g>` is not specified, then DS RRsets for the
-secure child zones need to be added manually.
-
-By default, all zone keys which have an available private key are used
-to generate signatures. The following command signs the zone, assuming
-it is in a file called ``zone.child.example``:
-
-``dnssec-signzone -o child.example zone.child.example``
-
-One output file is produced: ``zone.child.example.signed``. This file
-should be referenced by :iscman:`named.conf` as the input file for the zone.
-
-:iscman:`dnssec-signzone` also produces keyset and dsset files. These are used
-to provide the parent zone administrators with the ``DNSKEYs`` (or their
-corresponding ``DS`` records) that are the secure entry point to the zone.
-
-.. _dnssec_config:
-
-Configuring Servers for DNSSEC
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-To enable :iscman:`named` to validate answers received from other servers, the
-``dnssec-validation`` option must be set to either ``yes`` or ``auto``.
-
-When ``dnssec-validation`` is set to ``auto``, a trust anchor for the
-DNS root zone is automatically used. This trust anchor is provided
-as part of BIND and is kept up to date using :rfc:`5011` key management.
-
-When ``dnssec-validation`` is set to ``yes``, DNSSEC validation
-only occurs if at least one trust anchor has been explicitly configured
-in :iscman:`named.conf`, using a ``trust-anchors`` statement (or the
-``managed-keys`` and ``trusted-keys`` statements, both deprecated).
-
-When ``dnssec-validation`` is set to ``no``, DNSSEC validation does not
-occur.
-
-The default is ``auto`` unless BIND is built with
-``configure --disable-auto-validation``, in which case the default is
-``yes``.
-
-The keys specified in ``trust-anchors`` are copies of DNSKEY RRs for zones that are
-used to form the first link in the cryptographic chain of trust. Keys configured
-with the keyword ``static-key`` or ``static-ds`` are loaded directly into the
-table of trust anchors, and can only be changed by altering the
-configuration. Keys configured with ``initial-key`` or ``initial-ds`` are used
-to initialize :rfc:`5011` trust anchor maintenance, and are kept up-to-date
-automatically after the first time :iscman:`named` runs.
-
-``trust-anchors`` is described in more detail later in this document.
-
-BIND 9 does not verify signatures on load, so zone keys
-for authoritative zones do not need to be specified in the configuration
-file.
-
-After DNSSEC is established, a typical DNSSEC configuration looks
-something like the following. It has one or more public keys for the
-root, which allows answers from outside the organization to be validated.
-It also has several keys for parts of the namespace that the
-organization controls. These are here to ensure that :iscman:`named` is immune
-to compromised security in the DNSSEC components of parent zones.
-
-::
-
- trust-anchors {
- /* Root Key */
- "." initial-key 257 3 3 "BNY4wrWM1nCfJ+CXd0rVXyYmobt7sEEfK3clRbGaTwS
- JxrGkxJWoZu6I7PzJu/E9gx4UC1zGAHlXKdE4zYIpRh
- aBKnvcC2U9mZhkdUpd1Vso/HAdjNe8LmMlnzY3zy2Xy
- 4klWOADTPzSv9eamj8V18PHGjBLaVtYvk/ln5ZApjYg
- hf+6fElrmLkdaz MQ2OCnACR817DF4BBa7UR/beDHyp
- 5iWTXWSi6XmoJLbG9Scqc7l70KDqlvXR3M/lUUVRbke
- g1IPJSidmK3ZyCllh4XSKbje/45SKucHgnwU5jefMtq
- 66gKodQj+MiA21AfUVe7u99WzTLzY3qlxDhxYQQ20FQ
- 97S+LKUTpQcq27R7AT3/V5hRQxScINqwcz4jYqZD2fQ
- dgxbcDTClU0CRBdiieyLMNzXG3";
- /* Key for our organization's forward zone */
- example.com. static-ds 54135 5 2 "8EF922C97F1D07B23134440F19682E7519ADDAE180E20B1B1EC52E7F58B2831D"
-
- /* Key for our reverse zone. */
- 2.0.192.IN-ADDRPA.NET. static-key 257 3 5 "AQOnS4xn/IgOUpBPJ3bogzwc
- xOdNax071L18QqZnQQQAVVr+i
- LhGTnNGp3HoWQLUIzKrJVZ3zg
- gy3WwNT6kZo6c0tszYqbtvchm
- gQC8CzKojM/W16i6MG/eafGU3
- siaOdS0yOI6BgPsw+YZdzlYMa
- IJGf4M4dyoKIhzdZyQ2bYQrjy
- Q4LB0lC7aOnsMyYKHHYeRvPxj
- IQXmdqgOJGq+vsevG06zW+1xg
- YJh9rCIfnm1GX/KMgxLPG2vXT
- D/RnLX+D3T3UL7HJYHJhAZD5L
- 59VvjSPsZJHeDCUyWYrvPZesZ
- DIRvhDD52SKvbheeTJUm6Ehkz
- ytNN2SN96QRk8j/iI8ib";
- };
-
- options {
- ...
- dnssec-validation yes;
- };
-
-..
-
-.. note::
-
- None of the keys listed in this example are valid. In particular, the
- root key is not valid.
-
-When DNSSEC validation is enabled and properly configured, the resolver
-rejects any answers from signed, secure zones which fail to
-validate, and returns SERVFAIL to the client.
-
-Responses may fail to validate for any of several reasons, including
-missing, expired, or invalid signatures, a key which does not match the
-DS RRset in the parent zone, or an insecure response from a zone which,
-according to its parent, should have been secure.
-
-.. note::
-
- When the validator receives a response from an unsigned zone that has
- a signed parent, it must confirm with the parent that the zone was
- intentionally left unsigned. It does this by verifying, via signed
- and validated NSEC/NSEC3 records, that the parent zone contains no DS
- records for the child.
-
- If the validator *can* prove that the zone is insecure, then the
- response is accepted. However, if it cannot, the validator must assume an
- insecure response to be a forgery; it rejects the response and logs
- an error.
-
- The logged error reads "insecurity proof failed" and "got insecure
- response; parent indicates it should be secure."
-
-
-.. include:: dnssec.inc.rst
-.. include:: managed-keys.inc.rst
-.. include:: pkcs11.inc.rst
-.. include:: dlz.inc.rst
-.. include:: dyndb.inc.rst
-.. include:: catz.inc.rst
-
-.. _ipv6:
-
-IPv6 Support in BIND 9
-----------------------
-
-BIND 9 fully supports all currently defined forms of IPv6 name-to-address
-and address-to-name lookups. It also uses IPv6 addresses to
-make queries when running on an IPv6-capable system.
-
-For forward lookups, BIND 9 supports only AAAA records. :rfc:`3363`
-deprecated the use of A6 records, and client-side support for A6 records
-was accordingly removed from BIND 9. However, authoritative BIND 9 name
-servers still load zone files containing A6 records correctly, answer
-queries for A6 records, and accept zone transfer for a zone containing
-A6 records.
-
-For IPv6 reverse lookups, BIND 9 supports the traditional "nibble"
-format used in the ``ip6.arpa`` domain, as well as the older, deprecated
-``ip6.int`` domain. Older versions of BIND 9 supported the "binary label"
-(also known as "bitstring") format, but support of binary labels has
-been completely removed per :rfc:`3363`. Many applications in BIND 9 do not
-understand the binary label format at all anymore, and return an
-error if one is given. In particular, an authoritative BIND 9 name server will
-not load a zone file containing binary labels.
-
-Address Lookups Using AAAA Records
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-The IPv6 AAAA record is a parallel to the IPv4 A record, and, unlike the
-deprecated A6 record, specifies the entire IPv6 address in a single
-record. For example:
-
-::
-
- $ORIGIN example.com.
- host 3600 IN AAAA 2001:db8::1
-
-Use of IPv4-in-IPv6 mapped addresses is not recommended. If a host has
-an IPv4 address, use an A record, not a AAAA, with
-``::ffff:192.168.42.1`` as the address.
-
-Address-to-Name Lookups Using Nibble Format
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-When looking up an address in nibble format, the address components are
-simply reversed, just as in IPv4, and ``ip6.arpa.`` is appended to the
-resulting name. For example, the following commands produce a reverse name
-lookup for a host with address ``2001:db8::1``:
-
-::
-
- $ORIGIN 0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.
- 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 14400 IN PTR (
- host.example.com. )
--- /dev/null
+.. 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.
+
+.. include:: advanced.inc.rst
+.. include:: dlz.inc.rst
+.. include:: dyndb.inc.rst
+.. include:: catz.inc.rst
--- /dev/null
+.. 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.
+
+.. include:: security.inc.rst
+.. include:: tsig.inc.rst
+.. include:: tkey.inc.rst
+.. include:: sig0.inc.rst
--- /dev/null
+.. 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.
+
+.. include:: dnssec.inc.rst
+.. include:: managed-keys.inc.rst
+.. include:: pkcs11.inc.rst
.. See the COPYRIGHT file distributed with this work for additional
.. information regarding copyright ownership.
-.. _dnssec.dynamic.zones:
+.. _dnssec:
+
+DNSSEC
+------
+
+Cryptographic authentication of DNS information is possible through the
+DNS Security ("DNSSEC-bis") extensions, defined in :rfc:`4033`, :rfc:`4034`,
+and :rfc:`4035`. This section describes the creation and use of DNSSEC
+signed zones.
+
+In order to set up a DNSSEC secure zone, there are a series of steps
+which must be followed. BIND 9 ships with several tools that are used in
+this process, which are explained in more detail below. In all cases,
+the ``-h`` option prints a full list of parameters. Note that the DNSSEC
+tools require the keyset files to be in the working directory or the
+directory specified by the ``-d`` option.
+
+There must also be communication with the administrators of the parent
+and/or child zone to transmit keys. A zone's security status must be
+indicated by the parent zone for a DNSSEC-capable resolver to trust its
+data. This is done through the presence or absence of a ``DS`` record at
+the delegation point.
+
+For other servers to trust data in this zone, they must be
+statically configured with either this zone's zone key or the zone key of
+another zone above this one in the DNS tree.
+
+.. _generating_dnssec_keys:
+
+DNSSEC Keys
+~~~~~~~~~~~
+
+Generating Keys
+^^^^^^^^^^^^^^^
+
+The :iscman:`dnssec-keygen` program is used to generate keys.
+
+A secure zone must contain one or more zone keys. The zone keys
+sign all other records in the zone, as well as the zone keys of any
+secure delegated zones. Zone keys must have the same name as the zone, have a
+name type of ``ZONE``, and be usable for authentication. It is
+recommended that zone keys use a cryptographic algorithm designated as
+"mandatory to implement" by the IETF. Currently there are two algorithms,
+RSASHA256 and ECDSAP256SHA256; ECDSAP256SHA256 is recommended for
+current and future deployments.
+
+The following command generates an ECDSAP256SHA256 key for the
+``child.example`` zone:
+
+``dnssec-keygen -a ECDSAP256SHA256 -n ZONE child.example.``
+
+Two output files are produced: ``Kchild.example.+013+12345.key`` and
+``Kchild.example.+013+12345.private`` (where 12345 is an example of a
+key tag). The key filenames contain the key name (``child.example.``),
+the algorithm (5 is RSASHA1, 8 is RSASHA256, 13 is ECDSAP256SHA256, 15 is
+ED25519, etc.), and the key tag (12345 in this case). The private key (in
+the ``.private`` file) is used to generate signatures, and the public
+key (in the ``.key`` file) is used for signature verification.
+
+To generate another key with the same properties but with a different
+key tag, repeat the above command.
+
+The :iscman:`dnssec-keyfromlabel` program is used to get a key pair from a
+crypto hardware device and build the key files. Its usage is similar to
+:iscman:`dnssec-keygen`.
+
+The public keys should be inserted into the zone file by including the
+``.key`` files using ``$INCLUDE`` statements.
+
+.. _dnssec_zone_signing:
+
+Signing the Zone
+^^^^^^^^^^^^^^^^
+
+The :iscman:`dnssec-signzone` program is used to sign a zone.
+
+Any ``keyset`` files corresponding to secure sub-zones should be
+present. The zone signer generates ``NSEC``, ``NSEC3``, and ``RRSIG``
+records for the zone, as well as ``DS`` for the child zones if :option:`-g <dnssec-signzone -g>`
+is specified. If :option:`-g <dnssec-signzone -g>` is not specified, then DS RRsets for the
+secure child zones need to be added manually.
+
+By default, all zone keys which have an available private key are used
+to generate signatures. The following command signs the zone, assuming
+it is in a file called ``zone.child.example``:
+
+``dnssec-signzone -o child.example zone.child.example``
+
+One output file is produced: ``zone.child.example.signed``. This file
+should be referenced by :iscman:`named.conf` as the input file for the zone.
+
+:iscman:`dnssec-signzone` also produces keyset and dsset files. These are used
+to provide the parent zone administrators with the ``DNSKEYs`` (or their
+corresponding ``DS`` records) that are the secure entry point to the zone.
+
+.. _dnssec_config:
+
+Configuring Servers for DNSSEC
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+To enable :iscman:`named` to validate answers received from other servers, the
+``dnssec-validation`` option must be set to either ``yes`` or ``auto``.
+
+When ``dnssec-validation`` is set to ``auto``, a trust anchor for the
+DNS root zone is automatically used. This trust anchor is provided
+as part of BIND and is kept up to date using :rfc:`5011` key management.
+
+When ``dnssec-validation`` is set to ``yes``, DNSSEC validation
+only occurs if at least one trust anchor has been explicitly configured
+in :iscman:`named.conf`, using a ``trust-anchors`` statement (or the
+``managed-keys`` and ``trusted-keys`` statements, both deprecated).
+
+When ``dnssec-validation`` is set to ``no``, DNSSEC validation does not
+occur.
+
+The default is ``auto`` unless BIND is built with
+``configure --disable-auto-validation``, in which case the default is
+``yes``.
+
+The keys specified in ``trust-anchors`` are copies of DNSKEY RRs for zones that are
+used to form the first link in the cryptographic chain of trust. Keys configured
+with the keyword ``static-key`` or ``static-ds`` are loaded directly into the
+table of trust anchors, and can only be changed by altering the
+configuration. Keys configured with ``initial-key`` or ``initial-ds`` are used
+to initialize :rfc:`5011` trust anchor maintenance, and are kept up-to-date
+automatically after the first time :iscman:`named` runs.
+
+``trust-anchors`` is described in more detail later in this document.
+
+BIND 9 does not verify signatures on load, so zone keys
+for authoritative zones do not need to be specified in the configuration
+file.
+
+After DNSSEC is established, a typical DNSSEC configuration looks
+something like the following. It has one or more public keys for the
+root, which allows answers from outside the organization to be validated.
+It also has several keys for parts of the namespace that the
+organization controls. These are here to ensure that :iscman:`named` is immune
+to compromised security in the DNSSEC components of parent zones.
+
+::
+
+ trust-anchors {
+ /* Root Key */
+ "." initial-key 257 3 3 "BNY4wrWM1nCfJ+CXd0rVXyYmobt7sEEfK3clRbGaTwS
+ JxrGkxJWoZu6I7PzJu/E9gx4UC1zGAHlXKdE4zYIpRh
+ aBKnvcC2U9mZhkdUpd1Vso/HAdjNe8LmMlnzY3zy2Xy
+ 4klWOADTPzSv9eamj8V18PHGjBLaVtYvk/ln5ZApjYg
+ hf+6fElrmLkdaz MQ2OCnACR817DF4BBa7UR/beDHyp
+ 5iWTXWSi6XmoJLbG9Scqc7l70KDqlvXR3M/lUUVRbke
+ g1IPJSidmK3ZyCllh4XSKbje/45SKucHgnwU5jefMtq
+ 66gKodQj+MiA21AfUVe7u99WzTLzY3qlxDhxYQQ20FQ
+ 97S+LKUTpQcq27R7AT3/V5hRQxScINqwcz4jYqZD2fQ
+ dgxbcDTClU0CRBdiieyLMNzXG3";
+ /* Key for our organization's forward zone */
+ example.com. static-ds 54135 5 2 "8EF922C97F1D07B23134440F19682E7519ADDAE180E20B1B1EC52E7F58B2831D"
+
+ /* Key for our reverse zone. */
+ 2.0.192.IN-ADDRPA.NET. static-key 257 3 5 "AQOnS4xn/IgOUpBPJ3bogzwc
+ xOdNax071L18QqZnQQQAVVr+i
+ LhGTnNGp3HoWQLUIzKrJVZ3zg
+ gy3WwNT6kZo6c0tszYqbtvchm
+ gQC8CzKojM/W16i6MG/eafGU3
+ siaOdS0yOI6BgPsw+YZdzlYMa
+ IJGf4M4dyoKIhzdZyQ2bYQrjy
+ Q4LB0lC7aOnsMyYKHHYeRvPxj
+ IQXmdqgOJGq+vsevG06zW+1xg
+ YJh9rCIfnm1GX/KMgxLPG2vXT
+ D/RnLX+D3T3UL7HJYHJhAZD5L
+ 59VvjSPsZJHeDCUyWYrvPZesZ
+ DIRvhDD52SKvbheeTJUm6Ehkz
+ ytNN2SN96QRk8j/iI8ib";
+ };
+
+ options {
+ ...
+ dnssec-validation yes;
+ };
+
+..
+
+.. note::
+
+ None of the keys listed in this example are valid. In particular, the
+ root key is not valid.
+
+When DNSSEC validation is enabled and properly configured, the resolver
+rejects any answers from signed, secure zones which fail to
+validate, and returns SERVFAIL to the client.
+
+Responses may fail to validate for any of several reasons, including
+missing, expired, or invalid signatures, a key which does not match the
+DS RRset in the parent zone, or an insecure response from a zone which,
+according to its parent, should have been secure.
+
+.. note::
+
+ When the validator receives a response from an unsigned zone that has
+ a signed parent, it must confirm with the parent that the zone was
+ intentionally left unsigned. It does this by verifying, via signed
+ and validated NSEC/NSEC3 records, that the parent zone contains no DS
+ records for the child.
+
+ If the validator *can* prove that the zone is insecure, then the
+ response is accepted. However, if it cannot, the validator must assume an
+ insecure response to be a forgery; it rejects the response and logs
+ an error.
+
+ The logged error reads "insecurity proof failed" and "got insecure
+ response; parent indicates it should be secure."
+
+
+.. _dnssec_dynamic_zones:
DNSSEC, Dynamic Zones, and Automatic Signing
---------------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Converting From Insecure to Secure
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
A zone can be changed from insecure to secure in three ways: using a
dynamic DNS update, via the ``auto-dnssec`` zone option, or by setting a
};
Dynamic DNS Update Method
-~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^
To insert the keys via dynamic update:
other updates are possible as well.
Fully Automatic Zone Signing
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To enable automatic signing, set a ``dnssec-policy`` or add the
``auto-dnssec`` option to the zone statement in :iscman:`named.conf`.
been done, the configuration fails.
Private Type Records
-~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^
The state of the signing process is signaled by private type records
(with a default type value of 65534). When signing is complete, those
0x20 NONSEC
DNSKEY Rollovers
-~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^
As with insecure-to-secure conversions, DNSSEC keyrolls can be done
in two ways: using a dynamic DNS update, or via the ``auto-dnssec`` zone
option.
Dynamic DNS Update Method
-~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^
To perform key rollovers via a dynamic update, the ``K*``
files for the new keys must be added so that :iscman:`named` can find them.
old key after the update completes.
Automatic Key Rollovers
-~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^
When a new key reaches its activation date (as set by :iscman:`dnssec-keygen`
or :iscman:`dnssec-settime`), and if the ``auto-dnssec`` zone option is set to
after which it is safe to remove the old key from the DNSKEY RRset.
NSEC3PARAM Rollovers via UPDATE
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The new NSEC3PARAM record can be added via dynamic update. When the new NSEC3
chain has been generated, the NSEC3PARAM flag field is set to zero. At
removed after the update request completes.
Converting From NSEC to NSEC3
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Add a ``nsec3param`` option to your ``dnssec-policy`` and
run :option:`rndc reconfig`.
added before the NSEC chain is destroyed.
Converting From NSEC3 to NSEC
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To do this, remove the ``nsec3param`` option from the ``dnssec-policy`` and
run :option:`rndc reconfig`.
is removed.
Converting From Secure to Insecure
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To convert a signed zone to unsigned using dynamic DNS, delete all the
DNSKEY records from the zone apex using :iscman:`nsupdate`. All signatures,
should be removed or changed to ``allow`` instead; otherwise it will re-sign.
Periodic Re-signing
-~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^
In any secure zone which supports dynamic updates, :iscman:`named`
periodically re-signs RRsets which have not been re-signed as a result of
spread the re-sign load over time rather than all at once.
NSEC3 and OPTOUT
-~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^
:iscman:`named` only supports creating new NSEC3 chains where all the NSEC3
records in the zone have the same OPTOUT state. :iscman:`named` supports
chapter2
chapter3
chapter4
+ chapter5
+ chapter6
+ chapter7
reference
- advanced
- security
troubleshooting
chapter10
.. _rfc5011.support:
Dynamic Trust Anchor Management
--------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BIND is able to maintain DNSSEC trust anchors using :rfc:`5011` key
management. This feature allows :iscman:`named` to keep track of changes to
to configuration files.
Validating Resolver
-~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^
To configure a validating resolver to use :rfc:`5011` to maintain a trust
anchor, configure the trust anchor using a ``trust-anchors`` statement and
:ref:`trust-anchors`.
Authoritative Server
-~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^
To set up an authoritative zone for :rfc:`5011` trust anchor maintenance,
generate two (or more) key signing keys (KSKs) for the zone. Sign the
.. _pkcs11:
PKCS#11 (Cryptoki) Support
---------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~
Public Key Cryptography Standard #11 (PKCS#11) defines a
platform-independent API for the control of hardware security modules
.. _OpenSC: https://github.com/OpenSC/libp11
Prerequisites
-~~~~~~~~~~~~~
+^^^^^^^^^^^^^
See the documentation provided by the HSM vendor for information about
installing, initializing, testing, and troubleshooting the HSM.
$ /opt/pkcs11/usr/bin/softhsm-util --init-token 0 --slot 0 --label softhsmv2
OpenSSL-based PKCS#11
-~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^
OpenSSL-based PKCS#11 uses engine_pkcs11 OpenSSL engine from libp11 project.
https://gitlab.isc.org/isc-projects/bind9/-/wikis/BIND-9-PKCS11
Using the HSM
-~~~~~~~~~~~~~
+^^^^^^^^^^^^^
The canonical documentation for configuring engine_pkcs11 is in the
`libp11/README.md`_, but here's copy of working configuration for
init = 0
Key Generation
-~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^
HSM keys can now be created and used. We are going to assume that you already
have a BIND 9 installed, either from a package, or from the sources, and the
Specifying the Engine on the Command Line
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When using OpenSSL-based PKCS#11, the "engine" to be used by OpenSSL can be
specified in :iscman:`named` and all of the BIND ``dnssec-*`` tools by using the ``-E
dnssec-signzone -E pkcs11 -S -o example.net example.net
Running :iscman:`named` With Automatic Zone Re-signing
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The zone can also be signed automatically by named. Again, we need to provide
the name of the OpenSSL engine using the :option:`-E <named -E>` command line option.
.. See the COPYRIGHT file distributed with this work for additional
.. information regarding copyright ownership.
-.. Security:
+.. _security:
-BIND 9 Security Considerations
-==============================
+Security Configurations
+=======================
-.. _Access_Control_Lists:
+.. _file_permissions:
+
+.. _access_Control_Lists:
Access Control Lists
--------------------
subdomain and delegate that subdomain to a separate zone. This way, the
top-level zone containing critical data, such as the IP addresses of
public web and mail servers, need not allow dynamic updates at all.
+
+.. _sec_file_transfer:
+
+.. _dns_over_tls:
--- /dev/null
+.. 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.
+
+SIG(0)
+------
+
+BIND partially supports DNSSEC SIG(0) transaction signatures as
+specified in :rfc:`2535` and :rfc:`2931`. SIG(0) uses public/private keys to
+authenticate messages. Access control is performed in the same manner as with
+TSIG keys; privileges can be granted or denied in ACL directives based
+on the key name.
+
+When a SIG(0) signed message is received, it is only verified if
+the key is known and trusted by the server. The server does not attempt
+to recursively fetch or validate the key.
+
+SIG(0) signing of multiple-message TCP streams is not supported.
+
+The only tool shipped with BIND 9 that generates SIG(0) signed messages
+is :iscman:`nsupdate`.
--- /dev/null
+.. 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.
+
+TKEY
+----
+
+TKEY (Transaction KEY) is a mechanism for automatically negotiating a
+shared secret between two hosts, originally specified in :rfc:`2930`.
+
+There are several TKEY "modes" that specify how a key is to be generated
+or assigned. BIND 9 implements only one of these modes: Diffie-Hellman
+key exchange. Both hosts are required to have a KEY record with
+algorithm DH (though this record is not required to be present in a
+zone).
+
+The TKEY process is initiated by a client or server by sending a query
+of type TKEY to a TKEY-aware server. The query must include an
+appropriate KEY record in the additional section, and must be signed
+using either TSIG or SIG(0) with a previously established key. The
+server's response, if successful, contains a TKEY record in its
+answer section. After this transaction, both participants have
+enough information to calculate a shared secret using Diffie-Hellman key
+exchange. The shared secret can then be used to sign subsequent
+transactions between the two servers.
+
+TSIG keys known by the server, including TKEY-negotiated keys, can be
+listed using :option:`rndc tsig-list`.
+
+TKEY-negotiated keys can be deleted from a server using
+:option:`rndc tsig-delete`. This can also be done via the TKEY protocol
+itself, by sending an authenticated TKEY query specifying the "key
+deletion" mode.
--- /dev/null
+.. 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.
+
+.. _tsig:
+
+TSIG
+----
+
+TSIG (Transaction SIGnatures) is a mechanism for authenticating DNS
+messages, originally specified in :rfc:`2845`. It allows DNS messages to be
+cryptographically signed using a shared secret. TSIG can be used in any
+DNS transaction, as a way to restrict access to certain server functions
+(e.g., recursive queries) to authorized clients when IP-based access
+control is insufficient or needs to be overridden, or as a way to ensure
+message authenticity when it is critical to the integrity of the server,
+such as with dynamic UPDATE messages or zone transfers from a primary to
+a secondary server.
+
+This section is a guide to setting up TSIG in BIND. It describes the
+configuration syntax and the process of creating TSIG keys.
+
+:iscman:`named` supports TSIG for server-to-server communication, and some of
+the tools included with BIND support it for sending messages to
+:iscman:`named`:
+
+ * :ref:`man_nsupdate` supports TSIG via the :option:`-k <nsupdate -k>`, :option:`-l <nsupdate -l>`, and :option:`-y <nsupdate -y>` command-line options, or via the ``key`` command when running interactively.
+ * :ref:`man_dig` supports TSIG via the :option:`-k <dig -k>` and :option:`-y <dig -y>` command-line options.
+
+Generating a Shared Key
+~~~~~~~~~~~~~~~~~~~~~~~
+
+TSIG keys can be generated using the :iscman:`tsig-keygen` command; the output
+of the command is a ``key`` directive suitable for inclusion in
+:iscman:`named.conf`. The key name, algorithm, and size can be specified by
+command-line parameters; the defaults are "tsig-key", HMAC-SHA256, and
+256 bits, respectively.
+
+Any string which is a valid DNS name can be used as a key name. For
+example, a key to be shared between servers called ``host1`` and ``host2``
+could be called "host1-host2.", and this key can be generated using:
+
+::
+
+ $ tsig-keygen host1-host2. > host1-host2.key
+
+This key may then be copied to both hosts. The key name and secret must
+be identical on both hosts. (Note: copying a shared secret from one
+server to another is beyond the scope of the DNS. A secure transport
+mechanism should be used: secure FTP, SSL, ssh, telephone, encrypted
+email, etc.)
+
+:iscman:`tsig-keygen` can also be run as :iscman:`ddns-confgen`, in which case its
+output includes additional configuration text for setting up dynamic DNS
+in :iscman:`named`. See :ref:`man_ddns-confgen` for details.
+
+Loading a New Key
+~~~~~~~~~~~~~~~~~
+
+For a key shared between servers called ``host1`` and ``host2``, the
+following could be added to each server's :iscman:`named.conf` file:
+
+::
+
+ key "host1-host2." {
+ algorithm hmac-sha256;
+ secret "DAopyf1mhCbFVZw7pgmNPBoLUq8wEUT7UuPoLENP2HY=";
+ };
+
+(This is the same key generated above using :iscman:`tsig-keygen`.)
+
+Since this text contains a secret, it is recommended that either
+:iscman:`named.conf` not be world-readable, or that the ``key`` directive be
+stored in a file which is not world-readable and which is included in
+:iscman:`named.conf` via the ``include`` directive.
+
+Once a key has been added to :iscman:`named.conf` and the server has been
+restarted or reconfigured, the server can recognize the key. If the
+server receives a message signed by the key, it is able to verify
+the signature. If the signature is valid, the response is signed
+using the same key.
+
+TSIG keys that are known to a server can be listed using the command
+:option:`rndc tsig-list`.
+
+Instructing the Server to Use a Key
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A server sending a request to another server must be told whether to use
+a key, and if so, which key to use.
+
+For example, a key may be specified for each server in the ``primaries``
+statement in the definition of a secondary zone; in this case, all SOA QUERY
+messages, NOTIFY messages, and zone transfer requests (AXFR or IXFR)
+are signed using the specified key. Keys may also be specified in
+the ``also-notify`` statement of a primary or secondary zone, causing NOTIFY
+messages to be signed using the specified key.
+
+Keys can also be specified in a ``server`` directive. Adding the
+following on ``host1``, if the IP address of ``host2`` is 10.1.2.3, would
+cause *all* requests from ``host1`` to ``host2``, including normal DNS
+queries, to be signed using the ``host1-host2.`` key:
+
+::
+
+ server 10.1.2.3 {
+ keys { host1-host2. ;};
+ };
+
+Multiple keys may be present in the ``keys`` statement, but only the
+first one is used. As this directive does not contain secrets, it can be
+used in a world-readable file.
+
+Requests sent by ``host2`` to ``host1`` would *not* be signed, unless a
+similar ``server`` directive were in ``host2``'s configuration file.
+
+When any server sends a TSIG-signed DNS request, it expects the
+response to be signed with the same key. If a response is not signed, or
+if the signature is not valid, the response is rejected.
+
+TSIG-Based Access Control
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+TSIG keys may be specified in ACL definitions and ACL directives such as
+``allow-query``, ``allow-transfer``, and ``allow-update``. The above key
+would be denoted in an ACL element as ``key host1-host2.``
+
+Here is an example of an ``allow-update`` directive using a TSIG key:
+
+::
+
+ allow-update { !{ !localnets; any; }; key host1-host2. ;};
+
+This allows dynamic updates to succeed only if the UPDATE request comes
+from an address in ``localnets``, *and* if it is signed using the
+``host1-host2.`` key.
+
+See :ref:`dynamic_update_policies` for a
+discussion of the more flexible ``update-policy`` statement.
+
+Errors
+~~~~~~
+
+Processing of TSIG-signed messages can result in several errors:
+
+- If a TSIG-aware server receives a message signed by an unknown key,
+ the response will be unsigned, with the TSIG extended error code set
+ to BADKEY.
+- If a TSIG-aware server receives a message from a known key but with
+ an invalid signature, the response will be unsigned, with the TSIG
+ extended error code set to BADSIG.
+- If a TSIG-aware server receives a message with a time outside of the
+ allowed range, the response will be signed but the TSIG extended
+ error code set to BADTIME, and the time values will be adjusted so
+ that the response can be successfully verified.
+
+In all of the above cases, the server returns a response code of
+NOTAUTH (not authenticated).
projects / thirdparty / bind9.git / commitdiff
