2873 lines
130 KiB
Python
2873 lines
130 KiB
Python
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
<!--
|
||
- Copyright (C) 2000-2018 Internet Systems Consortium, Inc. ("ISC")
|
||
-
|
||
- 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 http://mozilla.org/MPL/2.0/.
|
||
-->
|
||
<html lang="en">
|
||
<head>
|
||
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
|
||
<title>Chapter 4. Advanced DNS Features</title>
|
||
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
|
||
<link rel="home" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual">
|
||
<link rel="up" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual">
|
||
<link rel="prev" href="Bv9ARM.ch03.html" title="Chapter 3. Name Server Configuration">
|
||
<link rel="next" href="Bv9ARM.ch05.html" title="Chapter 5. The BIND 9 Lightweight Resolver">
|
||
</head>
|
||
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||
<div class="navheader">
|
||
<table width="100%" summary="Navigation header">
|
||
<tr><th colspan="3" align="center">Chapter 4. Advanced DNS Features</th></tr>
|
||
<tr>
|
||
<td width="20%" align="left">
|
||
<a accesskey="p" href="Bv9ARM.ch03.html">Prev</a> </td>
|
||
<th width="60%" align="center"> </th>
|
||
<td width="20%" align="right"> <a accesskey="n" href="Bv9ARM.ch05.html">Next</a>
|
||
</td>
|
||
</tr>
|
||
</table>
|
||
<hr>
|
||
</div>
|
||
<div class="chapter">
|
||
<div class="titlepage"><div><div><h1 class="title">
|
||
<a name="Bv9ARM.ch04"></a>Chapter 4. Advanced DNS Features</h1></div></div></div>
|
||
<div class="toc">
|
||
<p><b>Table of Contents</b></p>
|
||
<dl class="toc">
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#notify">Notify</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dynamic_update">Dynamic Update</a></span></dt>
|
||
<dd><dl><dt><span class="section"><a href="Bv9ARM.ch04.html#journal">The journal file</a></span></dt></dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#incremental_zone_transfers">Incremental Zone Transfers (IXFR)</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#split_dns">Split DNS</a></span></dt>
|
||
<dd><dl><dt><span class="section"><a href="Bv9ARM.ch04.html#split_dns_sample">Example split DNS setup</a></span></dt></dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#tsig">TSIG</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.6.5">Generating a Shared Key</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.6.6">Loading A New Key</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.6.7">Instructing the Server to Use a Key</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.6.8">TSIG-Based Access Control</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.6.9">Errors</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#tkey">TKEY</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#sig0">SIG(0)</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#DNSSEC">DNSSEC</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dnssec_keys">Generating Keys</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dnssec_signing">Signing the Zone</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dnssec_config">Configuring Servers</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dnssec.dynamic.zones">DNSSEC, Dynamic Zones, and Automatic Signing</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.2">Converting from insecure to secure</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.7">Dynamic DNS update method</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.15">Fully automatic zone signing</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.24">Private-type records</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.31">DNSKEY rollovers</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.33">Dynamic DNS update method</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.38">Automatic key rollovers</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.40">NSEC3PARAM rollovers via UPDATE</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.42">Converting from NSEC to NSEC3</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.44">Converting from NSEC3 to NSEC</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.46">Converting from secure to insecure</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.50">Periodic re-signing</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.10.52">NSEC3 and OPTOUT</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#rfc5011.support">Dynamic Trust Anchor Management</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.11.3">Validating Resolver</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.11.4">Authoritative Server</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#pkcs11">PKCS#11 (Cryptoki) support</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.6">Prerequisites</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.7">Native PKCS#11</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.8">OpenSSL-based PKCS#11</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.9">PKCS#11 Tools</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.10">Using the HSM</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.11">Specifying the engine on the command line</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.12.12">Running named with automatic zone re-signing</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dlz-info">DLZ (Dynamically Loadable Zones)</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.13.6">Configuring DLZ</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.13.7">Sample DLZ Driver</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#dyndb-info">DynDB (Dynamic Database)</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.14.5">Configuring DynDB</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.14.6">Sample DynDB Module</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#catz-info">Catalog Zones</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.15.4">Principle of Operation</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.15.5">Configuring Catalog Zones</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.15.6">Catalog Zone format</a></span></dt>
|
||
</dl></dd>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#ipv6">IPv6 Support in <acronym class="acronym">BIND</acronym> 9</a></span></dt>
|
||
<dd><dl>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.16.6">Address Lookups Using AAAA Records</a></span></dt>
|
||
<dt><span class="section"><a href="Bv9ARM.ch04.html#id-1.5.16.7">Address to Name Lookups Using Nibble Format</a></span></dt>
|
||
</dl></dd>
|
||
</dl>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="notify"></a>Notify</h2></div></div></div>
|
||
<p>
|
||
<acronym class="acronym">DNS</acronym> NOTIFY is a mechanism that allows master
|
||
servers to notify their slave servers of changes to a zone's data. In
|
||
response to a <span class="command"><strong>NOTIFY</strong></span> from a master server, the
|
||
slave will check to see that its version of the zone is the
|
||
current version and, if not, initiate a zone transfer.
|
||
</p>
|
||
|
||
<p>
|
||
For more information about <acronym class="acronym">DNS</acronym>
|
||
<span class="command"><strong>NOTIFY</strong></span>, see the description of the
|
||
<span class="command"><strong>notify</strong></span> option in <a class="xref" href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a> and
|
||
the description of the zone option <span class="command"><strong>also-notify</strong></span> in
|
||
<a class="xref" href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. The <span class="command"><strong>NOTIFY</strong></span>
|
||
protocol is specified in RFC 1996.
|
||
</p>
|
||
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
As a slave zone can also be a master to other slaves, <span class="command"><strong>named</strong></span>,
|
||
by default, sends <span class="command"><strong>NOTIFY</strong></span> messages for every zone
|
||
it loads. Specifying <span class="command"><strong>notify master-only;</strong></span> will
|
||
cause <span class="command"><strong>named</strong></span> to only send <span class="command"><strong>NOTIFY</strong></span> for master
|
||
zones that it loads.
|
||
</p>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="dynamic_update"></a>Dynamic Update</h2></div></div></div>
|
||
|
||
<p>
|
||
Dynamic Update is a method for adding, replacing or deleting
|
||
records in a master server by sending it a special form of DNS
|
||
messages. The format and meaning of these messages is specified
|
||
in RFC 2136.
|
||
</p>
|
||
|
||
<p>
|
||
Dynamic update is enabled by including an
|
||
<span class="command"><strong>allow-update</strong></span> or an <span class="command"><strong>update-policy</strong></span>
|
||
clause in the <span class="command"><strong>zone</strong></span> statement.
|
||
</p>
|
||
|
||
<p>
|
||
If the zone's <span class="command"><strong>update-policy</strong></span> is set to
|
||
<strong class="userinput"><code>local</code></strong>, updates to the zone
|
||
will be permitted for the key <code class="varname">local-ddns</code>,
|
||
which will be generated by <span class="command"><strong>named</strong></span> at startup.
|
||
See <a class="xref" href="Bv9ARM.ch06.html#dynamic_update_policies" title="Dynamic Update Policies">the section called “Dynamic Update Policies”</a> for more details.
|
||
</p>
|
||
|
||
<p>
|
||
Dynamic updates using Kerberos signed requests can be made
|
||
using the TKEY/GSS protocol by setting either the
|
||
<span class="command"><strong>tkey-gssapi-keytab</strong></span> option, or alternatively
|
||
by setting both the <span class="command"><strong>tkey-gssapi-credential</strong></span>
|
||
and <span class="command"><strong>tkey-domain</strong></span> options. Once enabled,
|
||
Kerberos signed requests will be matched against the update
|
||
policies for the zone, using the Kerberos principal as the
|
||
signer for the request.
|
||
</p>
|
||
|
||
<p>
|
||
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.
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="journal"></a>The journal file</h3></div></div></div>
|
||
|
||
<p>
|
||
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
|
||
<code class="filename">.jnl</code> 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.
|
||
</p>
|
||
|
||
<p>
|
||
The server will also occasionally write ("dump")
|
||
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 will be created
|
||
with the extensions <code class="filename">.jnw</code> and
|
||
<code class="filename">.jbk</code>; under ordinary circumstances, these
|
||
will be removed when the dump is complete, and can be safely
|
||
ignored.
|
||
</p>
|
||
|
||
<p>
|
||
When a server is restarted after a shutdown or crash, it will replay
|
||
the journal file to incorporate into the zone any updates that
|
||
took
|
||
place after the last zone dump.
|
||
</p>
|
||
|
||
<p>
|
||
Changes that result from incoming incremental zone transfers are
|
||
also
|
||
journalled in a similar way.
|
||
</p>
|
||
|
||
<p>
|
||
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 <span class="command"><strong>rndc stop</strong></span>.
|
||
</p>
|
||
|
||
<p>
|
||
If you have to make changes to a dynamic zone
|
||
manually, the following procedure will work:
|
||
Disable dynamic updates to the zone using
|
||
<span class="command"><strong>rndc freeze <em class="replaceable"><code>zone</code></em></strong></span>.
|
||
This will update the zone's master file with the changes
|
||
stored in its <code class="filename">.jnl</code> file.
|
||
Edit the zone file. Run
|
||
<span class="command"><strong>rndc thaw <em class="replaceable"><code>zone</code></em></strong></span>
|
||
to reload the changed zone and re-enable dynamic updates.
|
||
</p>
|
||
|
||
<p>
|
||
<span class="command"><strong>rndc sync <em class="replaceable"><code>zone</code></em></strong></span>
|
||
will update 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 <code class="filename">.jnl</code>
|
||
file after updating the zone file, use
|
||
<span class="command"><strong>rndc sync -clean</strong></span>.
|
||
</p>
|
||
|
||
</div>
|
||
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="incremental_zone_transfers"></a>Incremental Zone Transfers (IXFR)</h2></div></div></div>
|
||
|
||
<p>
|
||
The incremental zone transfer (IXFR) protocol is a way for
|
||
slave servers to transfer only changed data, instead of having to
|
||
transfer the entire zone. The IXFR protocol is specified in RFC
|
||
1995. See <a class="xref" href="Bv9ARM.ch11.html#proposed_standards" title="Proposed Standards">Proposed Standards</a>.
|
||
</p>
|
||
|
||
<p>
|
||
When acting as a master, <acronym class="acronym">BIND</acronym> 9
|
||
supports IXFR for those zones
|
||
where the necessary change history information is available. These
|
||
include master zones maintained by dynamic update and slave zones
|
||
whose data was obtained by IXFR. For manually maintained master
|
||
zones, and for slave zones obtained by performing a full zone
|
||
transfer (AXFR), IXFR is supported only if the option
|
||
<span class="command"><strong>ixfr-from-differences</strong></span> is set
|
||
to <strong class="userinput"><code>yes</code></strong>.
|
||
</p>
|
||
|
||
<p>
|
||
When acting as a slave, <acronym class="acronym">BIND</acronym> 9 will
|
||
attempt to use IXFR unless
|
||
it is explicitly disabled. For more information about disabling
|
||
IXFR, see the description of the <span class="command"><strong>request-ixfr</strong></span> clause
|
||
of the <span class="command"><strong>server</strong></span> statement.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="split_dns"></a>Split DNS</h2></div></div></div>
|
||
|
||
<p>
|
||
Setting up different views, or visibility, of the DNS space to
|
||
internal and external resolvers is usually referred to as a
|
||
<span class="emphasis"><em>Split DNS</em></span> setup. There are several
|
||
reasons an organization would want to set up its DNS this way.
|
||
</p>
|
||
<p>
|
||
One common reason for setting up a DNS system this way is
|
||
to hide "internal" DNS information from "external" clients on the
|
||
Internet. There is some debate as to whether or not 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 a Split DNS to present a consistent view of itself
|
||
to the outside world.
|
||
</p>
|
||
<p>
|
||
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 in to the internal network.
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="split_dns_sample"></a>Example split DNS setup</h3></div></div></div>
|
||
<p>
|
||
Let's say a company named <span class="emphasis"><em>Example, Inc.</em></span>
|
||
(<code class="literal">example.com</code>)
|
||
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.
|
||
</p>
|
||
<p>
|
||
<span class="emphasis"><em>Example, Inc.</em></span> 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.
|
||
</p>
|
||
<p>
|
||
In order to accomplish this, the company will set up two sets
|
||
of name servers. One set will be on the inside network (in the
|
||
reserved
|
||
IP space) and the other set will be on bastion hosts, which are
|
||
"proxy"
|
||
hosts that can talk to both sides of its network, in the DMZ.
|
||
</p>
|
||
<p>
|
||
The internal servers will be configured to forward all queries,
|
||
except queries for <code class="filename">site1.internal</code>, <code class="filename">site2.internal</code>, <code class="filename">site1.example.com</code>,
|
||
and <code class="filename">site2.example.com</code>, to the servers
|
||
in the
|
||
DMZ. These internal servers will have complete sets of information
|
||
for <code class="filename">site1.example.com</code>, <code class="filename">site2.example.com</code>, <code class="filename">site1.internal</code>,
|
||
and <code class="filename">site2.internal</code>.
|
||
</p>
|
||
<p>
|
||
To protect the <code class="filename">site1.internal</code> and <code class="filename">site2.internal</code> domains,
|
||
the internal name servers must be configured to disallow all queries
|
||
to these domains from any external hosts, including the bastion
|
||
hosts.
|
||
</p>
|
||
<p>
|
||
The external servers, which are on the bastion hosts, will
|
||
be configured to serve the "public" version of the <code class="filename">site1</code> and <code class="filename">site2.example.com</code> zones.
|
||
This could include things such as the host records for public servers
|
||
(<code class="filename">www.example.com</code> and <code class="filename">ftp.example.com</code>),
|
||
and mail exchange (MX) records (<code class="filename">a.mx.example.com</code> and <code class="filename">b.mx.example.com</code>).
|
||
</p>
|
||
<p>
|
||
In addition, the public <code class="filename">site1</code> and <code class="filename">site2.example.com</code> zones
|
||
should have special MX records that contain wildcard (`*') records
|
||
pointing to the bastion hosts. This is needed because external mail
|
||
servers do not have any other way of looking up how to deliver mail
|
||
to those internal hosts. With the wildcard records, the mail will
|
||
be delivered to the bastion host, which can then forward it on to
|
||
internal hosts.
|
||
</p>
|
||
<p>
|
||
Here's an example of a wildcard MX record:
|
||
</p>
|
||
<pre class="programlisting">* IN MX 10 external1.example.com.</pre>
|
||
<p>
|
||
Now that they accept mail on behalf of anything in the internal
|
||
network, the bastion hosts will need to know how to deliver mail
|
||
to internal hosts. In order for this to work properly, the resolvers
|
||
on
|
||
the bastion hosts will need to be configured to point to the internal
|
||
name servers for DNS resolution.
|
||
</p>
|
||
<p>
|
||
Queries for internal hostnames will be answered by the internal
|
||
servers, and queries for external hostnames will be forwarded back
|
||
out to the DNS servers on the bastion hosts.
|
||
</p>
|
||
<p>
|
||
In order for all this to work properly, internal clients will
|
||
need to be configured to query <span class="emphasis"><em>only</em></span> the internal
|
||
name servers for DNS queries. This could also be enforced via
|
||
selective
|
||
filtering on the network.
|
||
</p>
|
||
<p>
|
||
If everything has been set properly, <span class="emphasis"><em>Example, Inc.</em></span>'s
|
||
internal clients will now be able to:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
|
||
Look up any hostnames in the <code class="literal">site1</code>
|
||
and
|
||
<code class="literal">site2.example.com</code> zones.
|
||
|
||
</li>
|
||
<li class="listitem">
|
||
|
||
Look up any hostnames in the <code class="literal">site1.internal</code> and
|
||
<code class="literal">site2.internal</code> domains.
|
||
|
||
</li>
|
||
<li class="listitem">
|
||
Look up any hostnames on the Internet.
|
||
</li>
|
||
<li class="listitem">
|
||
Exchange mail with both internal and external people.
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
Hosts on the Internet will be able to:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
|
||
Look up any hostnames in the <code class="literal">site1</code>
|
||
and
|
||
<code class="literal">site2.example.com</code> zones.
|
||
|
||
</li>
|
||
<li class="listitem">
|
||
|
||
Exchange mail with anyone in the <code class="literal">site1</code> and
|
||
<code class="literal">site2.example.com</code> zones.
|
||
|
||
</li>
|
||
</ul></div>
|
||
|
||
<p>
|
||
Here is an example configuration for the setup we just
|
||
described above. Note that this is only configuration information;
|
||
for information on how to configure your zone files, see <a class="xref" href="Bv9ARM.ch03.html#sample_configuration" title="Sample Configurations">the section called “Sample Configurations”</a>.
|
||
</p>
|
||
|
||
<p>
|
||
Internal DNS server config:
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
|
||
acl internals { 172.16.72.0/24; 192.168.1.0/24; };
|
||
|
||
acl externals { <code class="varname">bastion-ips-go-here</code>; };
|
||
|
||
options {
|
||
...
|
||
...
|
||
forward only;
|
||
// forward to external servers
|
||
forwarders {
|
||
<code class="varname">bastion-ips-go-here</code>;
|
||
};
|
||
// sample allow-transfer (no one)
|
||
allow-transfer { none; };
|
||
// restrict query access
|
||
allow-query { internals; externals; };
|
||
// restrict recursion
|
||
allow-recursion { internals; };
|
||
...
|
||
...
|
||
};
|
||
|
||
// sample master zone
|
||
zone "site1.example.com" {
|
||
type master;
|
||
file "m/site1.example.com";
|
||
// do normal iterative resolution (do not forward)
|
||
forwarders { };
|
||
allow-query { internals; externals; };
|
||
allow-transfer { internals; };
|
||
};
|
||
|
||
// sample slave zone
|
||
zone "site2.example.com" {
|
||
type slave;
|
||
file "s/site2.example.com";
|
||
masters { 172.16.72.3; };
|
||
forwarders { };
|
||
allow-query { internals; externals; };
|
||
allow-transfer { internals; };
|
||
};
|
||
|
||
zone "site1.internal" {
|
||
type master;
|
||
file "m/site1.internal";
|
||
forwarders { };
|
||
allow-query { internals; };
|
||
allow-transfer { internals; }
|
||
};
|
||
|
||
zone "site2.internal" {
|
||
type slave;
|
||
file "s/site2.internal";
|
||
masters { 172.16.72.3; };
|
||
forwarders { };
|
||
allow-query { internals };
|
||
allow-transfer { internals; }
|
||
};
|
||
</pre>
|
||
|
||
<p>
|
||
External (bastion host) DNS server config:
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
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 slave zone
|
||
zone "site1.example.com" {
|
||
type master;
|
||
file "m/site1.foo.com";
|
||
allow-transfer { internals; externals; };
|
||
};
|
||
|
||
zone "site2.example.com" {
|
||
type slave;
|
||
file "s/site2.foo.com";
|
||
masters { another_bastion_host_maybe; };
|
||
allow-transfer { internals; externals; }
|
||
};
|
||
</pre>
|
||
|
||
<p>
|
||
In the <code class="filename">resolv.conf</code> (or equivalent) on
|
||
the bastion host(s):
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
search ...
|
||
nameserver 172.16.72.2
|
||
nameserver 172.16.72.3
|
||
nameserver 172.16.72.4
|
||
</pre>
|
||
|
||
</div>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="tsig"></a>TSIG</h2></div></div></div>
|
||
|
||
<p>
|
||
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 master to a slave server.
|
||
</p>
|
||
<p>
|
||
This is a guide to setting up TSIG in <acronym class="acronym">BIND</acronym>.
|
||
It describes the configuration syntax and the process of creating
|
||
TSIG keys.
|
||
</p>
|
||
<p>
|
||
<span class="command"><strong>named</strong></span> supports TSIG for server-to-server
|
||
communication, and some of the tools included with
|
||
<acronym class="acronym">BIND</acronym> support it for sending messages to
|
||
<span class="command"><strong>named</strong></span>:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
<a class="xref" href="man.nsupdate.html" title="nsupdate"><span class="refentrytitle"><span class="application">nsupdate</span></span>(1)</a> supports TSIG via the
|
||
<code class="option">-k</code>, <code class="option">-l</code> and
|
||
<code class="option">-y</code> command line options, or via
|
||
the <span class="command"><strong>key</strong></span> command when running
|
||
interactively.
|
||
</li>
|
||
<li class="listitem">
|
||
<a class="xref" href="man.dig.html" title="dig"><span class="refentrytitle">dig</span>(1)</a> supports TSIG via the
|
||
<code class="option">-k</code> and <code class="option">-y</code> command
|
||
line options.
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.6.5"></a>Generating a Shared Key</h3></div></div></div>
|
||
<p>
|
||
TSIG keys can be generated using the <span class="command"><strong>tsig-keygen</strong></span>
|
||
command; the output of the command is a <span class="command"><strong>key</strong></span> directive
|
||
suitable for inclusion in <code class="filename">named.conf</code>. The
|
||
key name, algorithm and size can be specified by command line parameters;
|
||
the defaults are "tsig-key", HMAC-SHA256, and 256 bits, respectively.
|
||
</p>
|
||
<p>
|
||
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
|
||
<span class="emphasis"><em>host1</em></span> and <span class="emphasis"><em>host2</em></span> could
|
||
be called "host1-host2.", and this key could be generated using:
|
||
</p>
|
||
<pre class="programlisting">
|
||
$ tsig-keygen host1-host2. > host1-host2.key
|
||
</pre>
|
||
<p>
|
||
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.)
|
||
</p>
|
||
<p>
|
||
<span class="command"><strong>tsig-keygen</strong></span> can also be run as
|
||
<span class="command"><strong>ddns-confgen</strong></span>, in which case its output includes
|
||
additional configuration text for setting up dynamic DNS in
|
||
<span class="command"><strong>named</strong></span>. See <a class="xref" href="man.ddns-confgen.html" title="ddns-confgen"><span class="refentrytitle"><span class="application">ddns-confgen</span></span>(8)</a>
|
||
for details.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.6.6"></a>Loading A New Key</h3></div></div></div>
|
||
<p>
|
||
For a key shared between servers called
|
||
<span class="emphasis"><em>host1</em></span> and <span class="emphasis"><em>host2</em></span>,
|
||
the following could be added to each server's
|
||
<code class="filename">named.conf</code> file:
|
||
</p>
|
||
<pre class="programlisting">
|
||
key "host1-host2." {
|
||
algorithm hmac-sha256;
|
||
secret "DAopyf1mhCbFVZw7pgmNPBoLUq8wEUT7UuPoLENP2HY=";
|
||
};
|
||
</pre>
|
||
<p>
|
||
(This is the same key generated above using
|
||
<span class="command"><strong>tsig-keygen</strong></span>.)
|
||
</p>
|
||
<p>
|
||
Since this text contains a secret, it
|
||
is recommended that either <code class="filename">named.conf</code> not be
|
||
world-readable, or that the <span class="command"><strong>key</strong></span> directive
|
||
be stored in a file which is not world-readable, and which is
|
||
included in <code class="filename">named.conf</code> via the
|
||
<span class="command"><strong>include</strong></span> directive.
|
||
</p>
|
||
<p>
|
||
Once a key has been added to <code class="filename">named.conf</code> 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 will be able to verify the signature. If the signature
|
||
is valid, the response will be signed using the same key.
|
||
</p>
|
||
<p>
|
||
TSIG keys that are known to a server can be listed using the
|
||
command <span class="command"><strong>rndc tsig-list</strong></span>.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.6.7"></a>Instructing the Server to Use a Key</h3></div></div></div>
|
||
<p>
|
||
A server sending a request to another server must be told whether
|
||
to use a key, and if so, which key to use.
|
||
</p>
|
||
<p>
|
||
For example, a key may be specified for each server in the
|
||
<span class="command"><strong>masters</strong></span> statement in the definition of a
|
||
slave zone; in this case, all SOA QUERY messages, NOTIFY
|
||
messages, and zone transfer requests (AXFR or IXFR) will be
|
||
signed using the specified key. Keys may also be specified
|
||
in the <span class="command"><strong>also-notify</strong></span> statement of a master
|
||
or slave zone, causing NOTIFY messages to be signed using
|
||
the specified key.
|
||
</p>
|
||
<p>
|
||
Keys can also be specified in a <span class="command"><strong>server</strong></span>
|
||
directive. Adding the following on <span class="emphasis"><em>host1</em></span>,
|
||
if the IP address of <span class="emphasis"><em>host2</em></span> is 10.1.2.3, would
|
||
cause <span class="emphasis"><em>all</em></span> requests from <span class="emphasis"><em>host1</em></span>
|
||
to <span class="emphasis"><em>host2</em></span>, including normal DNS queries, to be
|
||
signed using the <span class="command"><strong>host1-host2.</strong></span> key:
|
||
</p>
|
||
<pre class="programlisting">
|
||
server 10.1.2.3 {
|
||
keys { host1-host2. ;};
|
||
};
|
||
</pre>
|
||
<p>
|
||
Multiple keys may be present in the <span class="command"><strong>keys</strong></span>
|
||
statement, but only the first one is used. As this directive does
|
||
not contain secrets, it can be used in a world-readable file.
|
||
</p>
|
||
<p>
|
||
Requests sent by <span class="emphasis"><em>host2</em></span> to <span class="emphasis"><em>host1</em></span>
|
||
would <span class="emphasis"><em>not</em></span> be signed, unless a similar
|
||
<span class="command"><strong>server</strong></span> directive were in <span class="emphasis"><em>host2</em></span>'s
|
||
configuration file.
|
||
</p>
|
||
<p>
|
||
Whenever any server sends a TSIG-signed DNS request, it will expect
|
||
the response to be signed with the same key. If a response is not
|
||
signed, or if the signature is not valid, the response will be
|
||
rejected.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.6.8"></a>TSIG-Based Access Control</h3></div></div></div>
|
||
<p>
|
||
TSIG keys may be specified in ACL definitions and ACL directives
|
||
such as <span class="command"><strong>allow-query</strong></span>, <span class="command"><strong>allow-transfer</strong></span>
|
||
and <span class="command"><strong>allow-update</strong></span>.
|
||
The above key would be denoted in an ACL element as
|
||
<span class="command"><strong>key host1-host2.</strong></span>
|
||
</p>
|
||
<p>
|
||
An example of an <span class="command"><strong>allow-update</strong></span> directive using
|
||
a TSIG key:
|
||
</p>
|
||
<pre class="programlisting">
|
||
allow-update { !{ !localnets; any; }; key host1-host2. ;};
|
||
</pre>
|
||
<p>
|
||
This allows dynamic updates to succeed only if the UPDATE
|
||
request comes from an address in <span class="command"><strong>localnets</strong></span>,
|
||
<span class="emphasis"><em>and</em></span> if it is signed using the
|
||
<span class="command"><strong>host1-host2.</strong></span> key.
|
||
</p>
|
||
<p>
|
||
See <a class="xref" href="Bv9ARM.ch06.html#dynamic_update_policies" title="Dynamic Update Policies">the section called “Dynamic Update Policies”</a> for a discussion of
|
||
the more flexible <span class="command"><strong>update-policy</strong></span> statement.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.6.9"></a>Errors</h3></div></div></div>
|
||
<p>
|
||
Processing of TSIG-signed messages can result in several errors:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
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.
|
||
</li>
|
||
<li class="listitem">
|
||
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.
|
||
</li>
|
||
<li class="listitem">
|
||
If a TSIG-aware server receives a message with a time
|
||
outside of the allowed range, the response will be signed, with
|
||
the TSIG extended error code set to BADTIME, and the time values
|
||
will be adjusted so that the response can be successfully
|
||
verified.
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
In all of the above cases, the server will return a response code
|
||
of NOTAUTH (not authenticated).
|
||
</p>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="tkey"></a>TKEY</h2></div></div></div>
|
||
|
||
<p>
|
||
TKEY (Transaction KEY) is a mechanism for automatically negotiating
|
||
a shared secret between two hosts, originally specified in RFC 2930.
|
||
</p>
|
||
<p>
|
||
There are several TKEY "modes" that specify how a key is to be
|
||
generated or assigned. <acronym class="acronym">BIND</acronym> 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).
|
||
</p>
|
||
<p>
|
||
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, will
|
||
contain a TKEY record in its answer section. After this transaction,
|
||
both participants will have enough information to calculate a
|
||
shared secret using Diffie-Hellman key exchange. The shared secret
|
||
can then be used by to sign subsequent transactions between the
|
||
two servers.
|
||
</p>
|
||
<p>
|
||
TSIG keys known by the server, including TKEY-negotiated keys, can
|
||
be listed using <span class="command"><strong>rndc tsig-list</strong></span>.
|
||
</p>
|
||
<p>
|
||
TKEY-negotiated keys can be deleted from a server using
|
||
<span class="command"><strong>rndc tsig-delete</strong></span>. This can also be done via
|
||
the TKEY protocol itself, by sending an authenticated TKEY query
|
||
specifying the "key deletion" mode.
|
||
</p>
|
||
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="sig0"></a>SIG(0)</h2></div></div></div>
|
||
|
||
<p>
|
||
<acronym class="acronym">BIND</acronym> 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 TSIG keys; privileges can be
|
||
granted or denied in ACL directives based on the key name.
|
||
</p>
|
||
<p>
|
||
When a SIG(0) signed message is received, it will only be
|
||
verified if the key is known and trusted by the server. The
|
||
server will not attempt to recursively fetch or validate the
|
||
key.
|
||
</p>
|
||
<p>
|
||
SIG(0) signing of multiple-message TCP streams is not supported.
|
||
</p>
|
||
<p>
|
||
The only tool shipped with <acronym class="acronym">BIND</acronym> 9 that
|
||
generates SIG(0) signed messages is <span class="command"><strong>nsupdate</strong></span>.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="DNSSEC"></a>DNSSEC</h2></div></div></div>
|
||
<p>
|
||
Cryptographic authentication of DNS information is possible
|
||
through the DNS Security (<span class="emphasis"><em>DNSSEC-bis</em></span>) extensions,
|
||
defined in RFC 4033, RFC 4034, and RFC 4035.
|
||
This section describes the creation and use of DNSSEC signed zones.
|
||
</p>
|
||
|
||
<p>
|
||
In order to set up a DNSSEC secure zone, there are a series
|
||
of steps which must be followed. <acronym class="acronym">BIND</acronym>
|
||
9 ships
|
||
with several tools
|
||
that are used in this process, which are explained in more detail
|
||
below. In all cases, the <code class="option">-h</code> 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 <code class="option">-d</code> option, and
|
||
that the tools shipped with BIND 9.2.x and earlier are not compatible
|
||
with the current ones.
|
||
</p>
|
||
|
||
<p>
|
||
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 <code class="literal">DS</code> record at the
|
||
delegation
|
||
point.
|
||
</p>
|
||
|
||
<p>
|
||
For other servers to trust data in this zone, they must
|
||
either be statically configured with this zone's zone key or the
|
||
zone key of another zone above this one in the DNS tree.
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="dnssec_keys"></a>Generating Keys</h3></div></div></div>
|
||
|
||
<p>
|
||
The <span class="command"><strong>dnssec-keygen</strong></span> program is used to
|
||
generate keys.
|
||
</p>
|
||
|
||
<p>
|
||
A secure zone must contain one or more zone keys. The
|
||
zone keys will 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, a name type of
|
||
<span class="command"><strong>ZONE</strong></span>, and must be usable for
|
||
authentication.
|
||
It is recommended that zone keys use a cryptographic algorithm
|
||
designated as "mandatory to implement" by the IETF; currently
|
||
the only one is RSASHA1.
|
||
</p>
|
||
|
||
<p>
|
||
The following command will generate a 768-bit RSASHA1 key for
|
||
the <code class="filename">child.example</code> zone:
|
||
</p>
|
||
|
||
<p>
|
||
<strong class="userinput"><code>dnssec-keygen -a RSASHA1 -b 768 -n ZONE child.example.</code></strong>
|
||
</p>
|
||
|
||
<p>
|
||
Two output files will be produced:
|
||
<code class="filename">Kchild.example.+005+12345.key</code> and
|
||
<code class="filename">Kchild.example.+005+12345.private</code>
|
||
(where
|
||
12345 is an example of a key tag). The key filenames contain
|
||
the key name (<code class="filename">child.example.</code>),
|
||
algorithm (3
|
||
is DSA, 1 is RSAMD5, 5 is RSASHA1, etc.), and the key tag (12345 in
|
||
this case).
|
||
The private key (in the <code class="filename">.private</code>
|
||
file) is
|
||
used to generate signatures, and the public key (in the
|
||
<code class="filename">.key</code> file) is used for signature
|
||
verification.
|
||
</p>
|
||
|
||
<p>
|
||
To generate another key with the same properties (but with
|
||
a different key tag), repeat the above command.
|
||
</p>
|
||
|
||
<p>
|
||
The <span class="command"><strong>dnssec-keyfromlabel</strong></span> program is used
|
||
to get a key pair from a crypto hardware and build the key
|
||
files. Its usage is similar to <span class="command"><strong>dnssec-keygen</strong></span>.
|
||
</p>
|
||
|
||
<p>
|
||
The public keys should be inserted into the zone file by
|
||
including the <code class="filename">.key</code> files using
|
||
<span class="command"><strong>$INCLUDE</strong></span> statements.
|
||
</p>
|
||
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="dnssec_signing"></a>Signing the Zone</h3></div></div></div>
|
||
|
||
<p>
|
||
The <span class="command"><strong>dnssec-signzone</strong></span> program is used
|
||
to sign a zone.
|
||
</p>
|
||
|
||
<p>
|
||
Any <code class="filename">keyset</code> files corresponding to
|
||
secure subzones should be present. The zone signer will
|
||
generate <code class="literal">NSEC</code>, <code class="literal">NSEC3</code>
|
||
and <code class="literal">RRSIG</code> records for the zone, as
|
||
well as <code class="literal">DS</code> for the child zones if
|
||
<code class="literal">'-g'</code> is specified. If <code class="literal">'-g'</code>
|
||
is not specified, then DS RRsets for the secure child
|
||
zones need to be added manually.
|
||
</p>
|
||
|
||
<p>
|
||
The following command signs the zone, assuming it is in a
|
||
file called <code class="filename">zone.child.example</code>. By
|
||
default, all zone keys which have an available private key are
|
||
used to generate signatures.
|
||
</p>
|
||
|
||
<p>
|
||
<strong class="userinput"><code>dnssec-signzone -o child.example zone.child.example</code></strong>
|
||
</p>
|
||
|
||
<p>
|
||
One output file is produced:
|
||
<code class="filename">zone.child.example.signed</code>. This
|
||
file
|
||
should be referenced by <code class="filename">named.conf</code>
|
||
as the
|
||
input file for the zone.
|
||
</p>
|
||
|
||
<p><span class="command"><strong>dnssec-signzone</strong></span>
|
||
will also produce a keyset and dsset files and optionally a
|
||
dlvset file. These are used to provide the parent zone
|
||
administrators with the <code class="literal">DNSKEYs</code> (or their
|
||
corresponding <code class="literal">DS</code> records) that are the
|
||
secure entry point to the zone.
|
||
</p>
|
||
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="dnssec_config"></a>Configuring Servers</h3></div></div></div>
|
||
|
||
<p>
|
||
To enable <span class="command"><strong>named</strong></span> to respond appropriately
|
||
to DNS requests from DNSSEC aware clients,
|
||
<span class="command"><strong>dnssec-enable</strong></span> must be set to yes.
|
||
(This is the default setting.)
|
||
</p>
|
||
|
||
<p>
|
||
To enable <span class="command"><strong>named</strong></span> to validate answers from
|
||
other servers, the <span class="command"><strong>dnssec-enable</strong></span> option
|
||
must be set to <strong class="userinput"><code>yes</code></strong>, and the
|
||
<span class="command"><strong>dnssec-validation</strong></span> options must be set to
|
||
<strong class="userinput"><code>yes</code></strong> or <strong class="userinput"><code>auto</code></strong>.
|
||
</p>
|
||
|
||
<p>
|
||
If <span class="command"><strong>dnssec-validation</strong></span> is set to
|
||
<strong class="userinput"><code>auto</code></strong>, then a default
|
||
trust anchor for the DNS root zone will be used.
|
||
If it is set to <strong class="userinput"><code>yes</code></strong>, however,
|
||
then at least one trust anchor must be configured
|
||
with a <span class="command"><strong>trusted-keys</strong></span> or
|
||
<span class="command"><strong>managed-keys</strong></span> statement in
|
||
<code class="filename">named.conf</code>, or DNSSEC validation
|
||
will not occur. The default setting is
|
||
<strong class="userinput"><code>yes</code></strong>.
|
||
</p>
|
||
|
||
<p>
|
||
<span class="command"><strong>trusted-keys</strong></span> are copies of DNSKEY RRs
|
||
for zones that are used to form the first link in the
|
||
cryptographic chain of trust. All keys listed in
|
||
<span class="command"><strong>trusted-keys</strong></span> (and corresponding zones)
|
||
are deemed to exist and only the listed keys will be used
|
||
to validated the DNSKEY RRset that they are from.
|
||
</p>
|
||
|
||
<p>
|
||
<span class="command"><strong>managed-keys</strong></span> are trusted keys which are
|
||
automatically kept up to date via RFC 5011 trust anchor
|
||
maintenance.
|
||
</p>
|
||
|
||
<p>
|
||
<span class="command"><strong>trusted-keys</strong></span> and
|
||
<span class="command"><strong>managed-keys</strong></span> are described in more detail
|
||
later in this document.
|
||
</p>
|
||
|
||
<p>
|
||
Unlike <acronym class="acronym">BIND</acronym> 8, <acronym class="acronym">BIND</acronym>
|
||
9 does not verify signatures on load, so zone keys for
|
||
authoritative zones do not need to be specified in the
|
||
configuration file.
|
||
</p>
|
||
|
||
<p>
|
||
After DNSSEC gets established, a typical DNSSEC configuration
|
||
will look something like the following. It has one or
|
||
more public keys for the root. This allows answers from
|
||
outside the organization to be validated. It will also
|
||
have several keys for parts of the namespace the organization
|
||
controls. These are here to ensure that <span class="command"><strong>named</strong></span>
|
||
is immune to compromises in the DNSSEC components of the security
|
||
of parent zones.
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
managed-keys {
|
||
/* 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";
|
||
};
|
||
|
||
trusted-keys {
|
||
/* Key for our organization's forward zone */
|
||
example.com. 257 3 5 "AwEAAaxPMcR2x0HbQV4WeZB6oEDX+r0QM6
|
||
5KbhTjrW1ZaARmPhEZZe3Y9ifgEuq7vZ/z
|
||
GZUdEGNWy+JZzus0lUptwgjGwhUS1558Hb
|
||
4JKUbbOTcM8pwXlj0EiX3oDFVmjHO444gL
|
||
kBOUKUf/mC7HvfwYH/Be22GnClrinKJp1O
|
||
g4ywzO9WglMk7jbfW33gUKvirTHr25GL7S
|
||
TQUzBb5Usxt8lgnyTUHs1t3JwCY5hKZ6Cq
|
||
FxmAVZP20igTixin/1LcrgX/KMEGd/biuv
|
||
F4qJCyduieHukuY3H4XMAcR+xia2nIUPvm
|
||
/oyWR8BW/hWdzOvnSCThlHf3xiYleDbt/o
|
||
1OTQ09A0=";
|
||
|
||
/* Key for our reverse zone. */
|
||
2.0.192.IN-ADDRPA.NET. 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-enable yes;
|
||
dnssec-validation yes;
|
||
};
|
||
</pre>
|
||
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
None of the keys listed in this example are valid. In particular,
|
||
the root key is not valid.
|
||
</p>
|
||
</div>
|
||
|
||
<p>
|
||
When DNSSEC validation is enabled and properly configured,
|
||
the resolver will reject any answers from signed, secure zones
|
||
which fail to validate, and will return SERVFAIL to the client.
|
||
</p>
|
||
|
||
<p>
|
||
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.
|
||
</p>
|
||
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
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.
|
||
</p>
|
||
<p>
|
||
If the validator <span class="emphasis"><em>can</em></span> prove that the zone
|
||
is insecure, then the response is accepted. However, if it
|
||
cannot, then it must assume an insecure response to be a
|
||
forgery; it rejects the response and logs an error.
|
||
</p>
|
||
<p>
|
||
The logged error reads "insecurity proof failed" and
|
||
"got insecure response; parent indicates it should be secure".
|
||
</p>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="dnssec.dynamic.zones"></a>DNSSEC, Dynamic Zones, and Automatic Signing</h2></div></div></div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.2"></a>Converting from insecure to secure</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>Changing a zone from insecure to secure can be done in two
|
||
ways: using a dynamic DNS update, or the
|
||
<span class="command"><strong>auto-dnssec</strong></span> zone option.</p>
|
||
<p>For either method, you need to configure
|
||
<span class="command"><strong>named</strong></span> so that it can see the
|
||
<code class="filename">K*</code> files which contain the public and private
|
||
parts of the keys that will be used to sign the zone. These files
|
||
will have been generated by
|
||
<span class="command"><strong>dnssec-keygen</strong></span>. You can do this by placing them
|
||
in the key-directory, as specified in
|
||
<code class="filename">named.conf</code>:</p>
|
||
<pre class="programlisting">
|
||
zone example.net {
|
||
type master;
|
||
update-policy local;
|
||
file "dynamic/example.net/example.net";
|
||
key-directory "dynamic/example.net";
|
||
};
|
||
</pre>
|
||
<p>If one KSK and one ZSK DNSKEY key have been generated, this
|
||
configuration will cause all records in the zone to be signed
|
||
with the ZSK, and the DNSKEY RRset to be signed with the KSK as
|
||
well. An NSEC chain will be generated as part of the initial
|
||
signing process.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.7"></a>Dynamic DNS update method</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>To insert the keys via dynamic update:</p>
|
||
<pre class="screen">
|
||
% nsupdate
|
||
> ttl 3600
|
||
> update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8=
|
||
> update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk=
|
||
> send
|
||
</pre>
|
||
<p>While the update request will complete almost immediately,
|
||
the zone will not be completely signed until
|
||
<span class="command"><strong>named</strong></span> has had time to walk the zone and
|
||
generate the NSEC and RRSIG records. The NSEC record at the apex
|
||
will be added last, to signal that there is a complete NSEC
|
||
chain.</p>
|
||
<p>If you wish to sign using NSEC3 instead of NSEC, you should
|
||
add an NSEC3PARAM record to the initial update request. If you
|
||
wish the NSEC3 chain to have the OPTOUT bit set, set it in the
|
||
flags field of the NSEC3PARAM record.</p>
|
||
<pre class="screen">
|
||
% nsupdate
|
||
> ttl 3600
|
||
> update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8=
|
||
> update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk=
|
||
> update add example.net NSEC3PARAM 1 1 100 1234567890
|
||
> send
|
||
</pre>
|
||
<p>Again, this update request will complete almost
|
||
immediately; however, the record won't show up until
|
||
<span class="command"><strong>named</strong></span> has had a chance to build/remove the
|
||
relevant chain. A private type record will be created to record
|
||
the state of the operation (see below for more details), and will
|
||
be removed once the operation completes.</p>
|
||
<p>While the initial signing and NSEC/NSEC3 chain generation
|
||
is happening, other updates are possible as well.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.15"></a>Fully automatic zone signing</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>To enable automatic signing, add the
|
||
<span class="command"><strong>auto-dnssec</strong></span> option to the zone statement in
|
||
<code class="filename">named.conf</code>.
|
||
<span class="command"><strong>auto-dnssec</strong></span> has two possible arguments:
|
||
<code class="constant">allow</code> or
|
||
<code class="constant">maintain</code>.</p>
|
||
<p>With
|
||
<span class="command"><strong>auto-dnssec allow</strong></span>,
|
||
<span class="command"><strong>named</strong></span> can search the key directory for keys
|
||
matching the zone, insert them into the zone, and use them to
|
||
sign the zone. It will do so only when it receives an
|
||
<span class="command"><strong>rndc sign <zonename></strong></span>.</p>
|
||
<p>
|
||
|
||
<span class="command"><strong>auto-dnssec maintain</strong></span> includes the above
|
||
functionality, but will also automatically adjust the zone's
|
||
DNSKEY records on schedule according to the keys' timing metadata.
|
||
(See <a class="xref" href="man.dnssec-keygen.html" title="dnssec-keygen"><span class="refentrytitle"><span class="application">dnssec-keygen</span></span>(8)</a> and
|
||
<a class="xref" href="man.dnssec-settime.html" title="dnssec-settime"><span class="refentrytitle"><span class="application">dnssec-settime</span></span>(8)</a> for more information.)
|
||
</p>
|
||
<p>
|
||
<span class="command"><strong>named</strong></span> will periodically search the key directory
|
||
for keys matching the zone, and if the keys' metadata indicates
|
||
that any change should be made the zone, such as adding, removing,
|
||
or revoking a key, then that action will be carried out. By default,
|
||
the key directory is checked for changes every 60 minutes; this period
|
||
can be adjusted with the <code class="option">dnssec-loadkeys-interval</code>, up
|
||
to a maximum of 24 hours. The <span class="command"><strong>rndc loadkeys</strong></span> forces
|
||
<span class="command"><strong>named</strong></span> to check for key updates immediately.
|
||
</p>
|
||
<p>
|
||
If keys are present in the key directory the first time the zone
|
||
is loaded, the zone will be signed immediately, without waiting for an
|
||
<span class="command"><strong>rndc sign</strong></span> or <span class="command"><strong>rndc loadkeys</strong></span>
|
||
command. (Those commands can still be used when there are unscheduled
|
||
key changes, however.)
|
||
</p>
|
||
<p>
|
||
When new keys are added to a zone, the TTL is set to match that
|
||
of any existing DNSKEY RRset. If there is no existing DNSKEY RRset,
|
||
then the TTL will be set to the TTL specified when the key was
|
||
created (using the <span class="command"><strong>dnssec-keygen -L</strong></span> option), if
|
||
any, or to the SOA TTL.
|
||
</p>
|
||
<p>
|
||
If you wish the zone to be signed using NSEC3 instead of NSEC,
|
||
submit an NSEC3PARAM record via dynamic update prior to the
|
||
scheduled publication and activation of the keys. If you wish the
|
||
NSEC3 chain to have the OPTOUT bit set, set it in the flags field
|
||
of the NSEC3PARAM record. The NSEC3PARAM record will not appear in
|
||
the zone immediately, but it will be stored for later reference. When
|
||
the zone is signed and the NSEC3 chain is completed, the NSEC3PARAM
|
||
record will appear in the zone.
|
||
</p>
|
||
<p>Using the
|
||
<span class="command"><strong>auto-dnssec</strong></span> option requires the zone to be
|
||
configured to allow dynamic updates, by adding an
|
||
<span class="command"><strong>allow-update</strong></span> or
|
||
<span class="command"><strong>update-policy</strong></span> statement to the zone
|
||
configuration. If this has not been done, the configuration will
|
||
fail.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.24"></a>Private-type records</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>The state of the signing process is signaled by
|
||
private-type records (with a default type value of 65534). When
|
||
signing is complete, these records will have a nonzero value for
|
||
the final octet (for those records which have a nonzero initial
|
||
octet).</p>
|
||
<p>The private type record format: If the first octet is
|
||
non-zero then the record indicates that the zone needs to be
|
||
signed with the key matching the record, or that all signatures
|
||
that match the record should be removed.</p>
|
||
<p>
|
||
</p>
|
||
<div class="literallayout"><p><br>
|
||
<br>
|
||
algorithm (octet 1)<br>
|
||
key id in network order (octet 2 and 3)<br>
|
||
removal flag (octet 4)<br>
|
||
complete flag (octet 5)<br>
|
||
</p></div>
|
||
<p>
|
||
</p>
|
||
<p>Only records flagged as "complete" can be removed via
|
||
dynamic update. Attempts to remove other private type records
|
||
will be silently ignored.</p>
|
||
<p>If the first octet is zero (this is a reserved algorithm
|
||
number that should never appear in a DNSKEY record) then the
|
||
record indicates changes to the NSEC3 chains are in progress. The
|
||
rest of the record contains an NSEC3PARAM record. The flag field
|
||
tells what operation to perform based on the flag bits.</p>
|
||
<p>
|
||
</p>
|
||
<div class="literallayout"><p><br>
|
||
<br>
|
||
0x01 OPTOUT<br>
|
||
0x80 CREATE<br>
|
||
0x40 REMOVE<br>
|
||
0x20 NONSEC<br>
|
||
</p></div>
|
||
<p>
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.31"></a>DNSKEY rollovers</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>As with insecure-to-secure conversions, rolling DNSSEC
|
||
keys can be done in two ways: using a dynamic DNS update, or the
|
||
<span class="command"><strong>auto-dnssec</strong></span> zone option.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.33"></a>Dynamic DNS update method</h3></div></div></div>
|
||
|
||
</div>
|
||
<p> To perform key rollovers via dynamic update, you need to add
|
||
the <code class="filename">K*</code> files for the new keys so that
|
||
<span class="command"><strong>named</strong></span> can find them. You can then add the new
|
||
DNSKEY RRs via dynamic update.
|
||
<span class="command"><strong>named</strong></span> will then cause the zone to be signed
|
||
with the new keys. When the signing is complete the private type
|
||
records will be updated so that the last octet is non
|
||
zero.</p>
|
||
<p>If this is for a KSK you need to inform the parent and any
|
||
trust anchor repositories of the new KSK.</p>
|
||
<p>You should then wait for the maximum TTL in the zone before
|
||
removing the old DNSKEY. If it is a KSK that is being updated,
|
||
you also need to wait for the DS RRset in the parent to be
|
||
updated and its TTL to expire. This ensures that all clients will
|
||
be able to verify at least one signature when you remove the old
|
||
DNSKEY.</p>
|
||
<p>The old DNSKEY can be removed via UPDATE. Take care to
|
||
specify the correct key.
|
||
<span class="command"><strong>named</strong></span> will clean out any signatures generated
|
||
by the old key after the update completes.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.38"></a>Automatic key rollovers</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>When a new key reaches its activation date (as set by
|
||
<span class="command"><strong>dnssec-keygen</strong></span> or <span class="command"><strong>dnssec-settime</strong></span>),
|
||
if the <span class="command"><strong>auto-dnssec</strong></span> zone option is set to
|
||
<code class="constant">maintain</code>, <span class="command"><strong>named</strong></span> will
|
||
automatically carry out the key rollover. If the key's algorithm
|
||
has not previously been used to sign the zone, then the zone will
|
||
be fully signed as quickly as possible. However, if the new key
|
||
is replacing an existing key of the same algorithm, then the
|
||
zone will be re-signed incrementally, with signatures from the
|
||
old key being replaced with signatures from the new key as their
|
||
signature validity periods expire. By default, this rollover
|
||
completes in 30 days, after which it will be safe to remove the
|
||
old key from the DNSKEY RRset.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.40"></a>NSEC3PARAM rollovers via UPDATE</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>Add the new NSEC3PARAM record via dynamic update. When the
|
||
new NSEC3 chain has been generated, the NSEC3PARAM flag field
|
||
will be zero. At this point you can remove the old NSEC3PARAM
|
||
record. The old chain will be removed after the update request
|
||
completes.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.42"></a>Converting from NSEC to NSEC3</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>To do this, you just need to add an NSEC3PARAM record. When
|
||
the conversion is complete, the NSEC chain will have been removed
|
||
and the NSEC3PARAM record will have a zero flag field. The NSEC3
|
||
chain will be generated before the NSEC chain is
|
||
destroyed.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.44"></a>Converting from NSEC3 to NSEC</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>To do this, use <span class="command"><strong>nsupdate</strong></span> to
|
||
remove all NSEC3PARAM records with a zero flag
|
||
field. The NSEC chain will be generated before the NSEC3 chain is
|
||
removed.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.46"></a>Converting from secure to insecure</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>To convert a signed zone to unsigned using dynamic DNS,
|
||
delete all the DNSKEY records from the zone apex using
|
||
<span class="command"><strong>nsupdate</strong></span>. All signatures, NSEC or NSEC3 chains,
|
||
and associated NSEC3PARAM records will be removed automatically.
|
||
This will take place after the update request completes.</p>
|
||
<p> This requires the
|
||
<span class="command"><strong>dnssec-secure-to-insecure</strong></span> option to be set to
|
||
<strong class="userinput"><code>yes</code></strong> in
|
||
<code class="filename">named.conf</code>.</p>
|
||
<p>In addition, if the <span class="command"><strong>auto-dnssec maintain</strong></span>
|
||
zone statement is used, it should be removed or changed to
|
||
<span class="command"><strong>allow</strong></span> instead (or it will re-sign).
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.50"></a>Periodic re-signing</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>In any secure zone which supports dynamic updates, <span class="command"><strong>named</strong></span>
|
||
will periodically re-sign RRsets which have not been re-signed as
|
||
a result of some update action. The signature lifetimes will be
|
||
adjusted so as to spread the re-sign load over time rather than
|
||
all at once.</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.10.52"></a>NSEC3 and OPTOUT</h3></div></div></div>
|
||
|
||
</div>
|
||
<p>
|
||
<span class="command"><strong>named</strong></span> only supports creating new NSEC3 chains
|
||
where all the NSEC3 records in the zone have the same OPTOUT
|
||
state.
|
||
<span class="command"><strong>named</strong></span> supports UPDATES to zones where the NSEC3
|
||
records in the chain have mixed OPTOUT state.
|
||
<span class="command"><strong>named</strong></span> does not support changing the OPTOUT
|
||
state of an individual NSEC3 record, the entire chain needs to be
|
||
changed if the OPTOUT state of an individual NSEC3 needs to be
|
||
changed.</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="rfc5011.support"></a>Dynamic Trust Anchor Management</h2></div></div></div>
|
||
|
||
<p>
|
||
BIND is able to maintain DNSSEC trust anchors using RFC 5011 key
|
||
management. This feature allows <span class="command"><strong>named</strong></span> to keep track
|
||
of changes to critical DNSSEC keys without any need for the operator to
|
||
make changes to configuration files.
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.11.3"></a>Validating Resolver</h3></div></div></div>
|
||
|
||
|
||
<p>To configure a validating resolver to use RFC 5011 to
|
||
maintain a trust anchor, configure the trust anchor using a
|
||
<span class="command"><strong>managed-keys</strong></span> statement. Information about
|
||
this can be found in
|
||
<a class="xref" href="Bv9ARM.ch06.html#managed-keys" title="managed-keys Statement Definition and Usage">the section called “<span class="command"><strong>managed-keys</strong></span> Statement Definition
|
||
and Usage”</a>.</p>
|
||
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.11.4"></a>Authoritative Server</h3></div></div></div>
|
||
|
||
<p>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 zone with one of them; this is the "active"
|
||
KSK. All KSKs which do not sign the zone are "stand-by"
|
||
keys.</p>
|
||
<p>Any validating resolver which is configured to use the
|
||
active KSK as an RFC 5011-managed trust anchor will take note
|
||
of the stand-by KSKs in the zone's DNSKEY RRset, and store them
|
||
for future reference. The resolver will recheck the zone
|
||
periodically, and after 30 days, if the new key is still there,
|
||
then the key will be accepted by the resolver as a valid trust
|
||
anchor for the zone. Any time after this 30-day acceptance
|
||
timer has completed, the active KSK can be revoked, and the
|
||
zone can be "rolled over" to the newly accepted key.</p>
|
||
<p>The easiest way to place a stand-by key in a zone is to
|
||
use the "smart signing" features of
|
||
<span class="command"><strong>dnssec-keygen</strong></span> and
|
||
<span class="command"><strong>dnssec-signzone</strong></span>. If a key with a publication
|
||
date in the past, but an activation date which is unset or in
|
||
the future, "
|
||
<span class="command"><strong>dnssec-signzone -S</strong></span>" will include the DNSKEY
|
||
record in the zone, but will not sign with it:</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>dnssec-keygen -K keys -f KSK -P now -A now+2y example.net</code></strong>
|
||
$ <strong class="userinput"><code>dnssec-signzone -S -K keys example.net</code></strong>
|
||
</pre>
|
||
<p>To revoke a key, the new command
|
||
<span class="command"><strong>dnssec-revoke</strong></span> has been added. This adds the
|
||
REVOKED bit to the key flags and re-generates the
|
||
<code class="filename">K*.key</code> and
|
||
<code class="filename">K*.private</code> files.</p>
|
||
<p>After revoking the active key, the zone must be signed
|
||
with both the revoked KSK and the new active KSK. (Smart
|
||
signing takes care of this automatically.)</p>
|
||
<p>Once a key has been revoked and used to sign the DNSKEY
|
||
RRset in which it appears, that key will never again be
|
||
accepted as a valid trust anchor by the resolver. However,
|
||
validation can proceed using the new active key (which had been
|
||
accepted by the resolver when it was a stand-by key).</p>
|
||
<p>See RFC 5011 for more details on key rollover
|
||
scenarios.</p>
|
||
<p>When a key has been revoked, its key ID changes,
|
||
increasing by 128, and wrapping around at 65535. So, for
|
||
example, the key "<code class="filename">Kexample.com.+005+10000</code>" becomes
|
||
"<code class="filename">Kexample.com.+005+10128</code>".</p>
|
||
<p>If two keys have IDs exactly 128 apart, and one is
|
||
revoked, then the two key IDs will collide, causing several
|
||
problems. To prevent this,
|
||
<span class="command"><strong>dnssec-keygen</strong></span> will not generate a new key if
|
||
another key is present which may collide. This checking will
|
||
only occur if the new keys are written to the same directory
|
||
which holds all other keys in use for that zone.</p>
|
||
<p>Older versions of BIND 9 did not have this precaution.
|
||
Exercise caution if using key revocation on keys that were
|
||
generated by previous releases, or if using keys stored in
|
||
multiple directories or on multiple machines.</p>
|
||
<p>It is expected that a future release of BIND 9 will
|
||
address this problem in a different way, by storing revoked
|
||
keys with their original unrevoked key IDs.</p>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="pkcs11"></a>PKCS#11 (Cryptoki) support</h2></div></div></div>
|
||
|
||
<p>
|
||
PKCS#11 (Public Key Cryptography Standard #11) defines a
|
||
platform-independent API for the control of hardware security
|
||
modules (HSMs) and other cryptographic support devices.
|
||
</p>
|
||
<p>
|
||
BIND 9 is known to work with three HSMs: The AEP Keyper, which has
|
||
been tested with Debian Linux, Solaris x86 and Windows Server 2003;
|
||
the Thales nShield, tested with Debian Linux; and the Sun SCA 6000
|
||
cryptographic acceleration board, tested with Solaris x86. In
|
||
addition, BIND can be used with all current versions of SoftHSM,
|
||
a software-based HSM simulator library produced by the OpenDNSSEC
|
||
project.
|
||
</p>
|
||
<p>
|
||
PKCS#11 makes use of a "provider library": a dynamically loadable
|
||
library which provides a low-level PKCS#11 interface to drive the HSM
|
||
hardware. The PKCS#11 provider library comes from the HSM vendor, and
|
||
it is specific to the HSM to be controlled.
|
||
</p>
|
||
<p>
|
||
There are two available mechanisms for PKCS#11 support in BIND 9:
|
||
OpenSSL-based PKCS#11 and native PKCS#11. When using the first
|
||
mechanism, BIND uses a modified version of OpenSSL, which loads
|
||
the provider library and operates the HSM indirectly; any
|
||
cryptographic operations not supported by the HSM can be carried
|
||
out by OpenSSL instead. The second mechanism enables BIND to bypass
|
||
OpenSSL completely; BIND loads the provider library itself, and uses
|
||
the PKCS#11 API to drive the HSM directly.
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.6"></a>Prerequisites</h3></div></div></div>
|
||
|
||
<p>
|
||
See the documentation provided by your HSM vendor for
|
||
information about installing, initializing, testing and
|
||
troubleshooting the HSM.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.7"></a>Native PKCS#11</h3></div></div></div>
|
||
|
||
<p>
|
||
Native PKCS#11 mode will only work with an HSM capable of carrying
|
||
out <span class="emphasis"><em>every</em></span> cryptographic operation BIND 9 may
|
||
need. The HSM's provider library must have a complete implementation
|
||
of the PKCS#11 API, so that all these functions are accessible. As of
|
||
this writing, only the Thales nShield HSM and SoftHSMv2 can be used
|
||
in this fashion. For other HSMs, including the AEP Keyper, Sun SCA
|
||
6000 and older versions of SoftHSM, use OpenSSL-based PKCS#11.
|
||
(Note: Eventually, when more HSMs become capable of supporting
|
||
native PKCS#11, it is expected that OpenSSL-based PKCS#11 will
|
||
be deprecated.)
|
||
</p>
|
||
<p>
|
||
To build BIND with native PKCS#11, configure as follows:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd bind9</code></strong>
|
||
$ <strong class="userinput"><code>./configure --enable-native-pkcs11 \
|
||
--with-pkcs11=<em class="replaceable"><code>provider-library-path</code></em></code></strong>
|
||
</pre>
|
||
<p>
|
||
This will cause all BIND tools, including <span class="command"><strong>named</strong></span>
|
||
and the <span class="command"><strong>dnssec-*</strong></span> and <span class="command"><strong>pkcs11-*</strong></span>
|
||
tools, to use the PKCS#11 provider library specified in
|
||
<em class="replaceable"><code>provider-library-path</code></em> for cryptography.
|
||
(The provider library path can be overridden using the
|
||
<code class="option">-E</code> in <span class="command"><strong>named</strong></span> and the
|
||
<span class="command"><strong>dnssec-*</strong></span> tools, or the <code class="option">-m</code> in
|
||
the <span class="command"><strong>pkcs11-*</strong></span> tools.)
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.7.6"></a>Building SoftHSMv2</h4></div></div></div>
|
||
|
||
<p>
|
||
SoftHSMv2, the latest development version of SoftHSM, is available
|
||
from
|
||
<a class="link" href="https://github.com/opendnssec/SoftHSMv2" target="_top">
|
||
https://github.com/opendnssec/SoftHSMv2
|
||
</a>.
|
||
It is a software library developed by the OpenDNSSEC project
|
||
(<a class="link" href="http://www.opendnssec.org" target="_top">
|
||
http://www.opendnssec.org
|
||
</a>)
|
||
which provides a PKCS#11 interface to a virtual HSM, implemented in
|
||
the form of a SQLite3 database on the local filesystem. It provides
|
||
less security than a true HSM, but it allows you to experiment with
|
||
native PKCS#11 when an HSM is not available. SoftHSMv2 can be
|
||
configured to use either OpenSSL or the Botan library to perform
|
||
cryptographic functions, but when using it for native PKCS#11 in
|
||
BIND, OpenSSL is required.
|
||
</p>
|
||
<p>
|
||
By default, the SoftHSMv2 configuration file is
|
||
<em class="replaceable"><code>prefix</code></em>/etc/softhsm2.conf (where
|
||
<em class="replaceable"><code>prefix</code></em> is configured at compile time).
|
||
This location can be overridden by the SOFTHSM2_CONF environment
|
||
variable. The SoftHSMv2 cryptographic store must be installed and
|
||
initialized before using it with BIND.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code> cd SoftHSMv2 </code></strong>
|
||
$ <strong class="userinput"><code> configure --with-crypto-backend=openssl --prefix=/opt/pkcs11/usr --enable-gost </code></strong>
|
||
$ <strong class="userinput"><code> make </code></strong>
|
||
$ <strong class="userinput"><code> make install </code></strong>
|
||
$ <strong class="userinput"><code> /opt/pkcs11/usr/bin/softhsm-util --init-token 0 --slot 0 --label softhsmv2 </code></strong>
|
||
</pre>
|
||
</div>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.8"></a>OpenSSL-based PKCS#11</h3></div></div></div>
|
||
|
||
<p>
|
||
OpenSSL-based PKCS#11 mode uses a modified version of the
|
||
OpenSSL library; stock OpenSSL does not fully support PKCS#11.
|
||
ISC provides a patch to OpenSSL to correct this. This patch is
|
||
based on work originally done by the OpenSolaris project; it has been
|
||
modified by ISC to provide new features such as PIN management and
|
||
key-by-reference.
|
||
</p>
|
||
<p>
|
||
There are two "flavors" of PKCS#11 support provided by
|
||
the patched OpenSSL, one of which must be chosen at
|
||
configuration time. The correct choice depends on the HSM
|
||
hardware:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
<p>
|
||
Use 'crypto-accelerator' with HSMs that have hardware
|
||
cryptographic acceleration features, such as the SCA 6000
|
||
board. This causes OpenSSL to run all supported
|
||
cryptographic operations in the HSM.
|
||
</p>
|
||
</li>
|
||
<li class="listitem">
|
||
<p>
|
||
Use 'sign-only' with HSMs that are designed to
|
||
function primarily as secure key storage devices, but lack
|
||
hardware acceleration. These devices are highly secure, but
|
||
are not necessarily any faster at cryptography than the
|
||
system CPU — often, they are slower. It is therefore
|
||
most efficient to use them only for those cryptographic
|
||
functions that require access to the secured private key,
|
||
such as zone signing, and to use the system CPU for all
|
||
other computationally-intensive operations. The AEP Keyper
|
||
is an example of such a device.
|
||
</p>
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
The modified OpenSSL code is included in the BIND 9 release,
|
||
in the form of a context diff against the latest versions of
|
||
OpenSSL. OpenSSL 0.9.8, 1.0.0, 1.0.1 and 1.0.2 are supported;
|
||
there are separate diffs for each version. In the examples to
|
||
follow, we use OpenSSL 0.9.8, but the same methods work with
|
||
OpenSSL 1.0.0 through 1.0.2.
|
||
</p>
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
The OpenSSL patches as of this writing (January 2016)
|
||
support versions 0.9.8zh, 1.0.0t, 1.0.1q and 1.0.2f.
|
||
ISC will provide updated patches as new versions of OpenSSL
|
||
are released. The version number in the following examples
|
||
is expected to change.
|
||
</p>
|
||
</div>
|
||
<p>
|
||
Before building BIND 9 with PKCS#11 support, it will be
|
||
necessary to build OpenSSL with the patch in place, and configure
|
||
it with the path to your HSM's PKCS#11 provider library.
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.8"></a>Patching OpenSSL</h4></div></div></div>
|
||
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>wget <a class="link" href="" target="_top">http://www.openssl.org/source/openssl-0.9.8zc.tar.gz</a></code></strong>
|
||
</pre>
|
||
<p>Extract the tarball:</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>tar zxf openssl-0.9.8zc.tar.gz</code></strong>
|
||
</pre>
|
||
<p>Apply the patch from the BIND 9 release:</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>patch -p1 -d openssl-0.9.8zc \
|
||
< bind9/bin/pkcs11/openssl-0.9.8zc-patch</code></strong>
|
||
</pre>
|
||
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Note</h3>
|
||
<p>
|
||
The patch file may not be compatible with the
|
||
"patch" utility on all operating systems. You may need to
|
||
install GNU patch.
|
||
</p>
|
||
</div>
|
||
<p>
|
||
When building OpenSSL, place it in a non-standard
|
||
location so that it does not interfere with OpenSSL libraries
|
||
elsewhere on the system. In the following examples, we choose
|
||
to install into "/opt/pkcs11/usr". We will use this location
|
||
when we configure BIND 9.
|
||
</p>
|
||
<p>
|
||
Later, when building BIND 9, the location of the custom-built
|
||
OpenSSL library will need to be specified via configure.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.9"></a>Building OpenSSL for the AEP Keyper on Linux</h4></div></div></div>
|
||
|
||
|
||
<p>
|
||
The AEP Keyper is a highly secure key storage device,
|
||
but does not provide hardware cryptographic acceleration. It
|
||
can carry out cryptographic operations, but it is probably
|
||
slower than your system's CPU. Therefore, we choose the
|
||
'sign-only' flavor when building OpenSSL.
|
||
</p>
|
||
<p>
|
||
The Keyper-specific PKCS#11 provider library is
|
||
delivered with the Keyper software. In this example, we place
|
||
it /opt/pkcs11/usr/lib:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cp pkcs11.GCC4.0.2.so.4.05 /opt/pkcs11/usr/lib/libpkcs11.so</code></strong>
|
||
</pre>
|
||
<p>
|
||
The Keyper library requires threads, so we
|
||
must specify -pthread.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd openssl-0.9.8zc</code></strong>
|
||
$ <strong class="userinput"><code>./Configure linux-x86_64 -pthread \
|
||
--pk11-libname=/opt/pkcs11/usr/lib/libpkcs11.so \
|
||
--pk11-flavor=sign-only \
|
||
--prefix=/opt/pkcs11/usr</code></strong>
|
||
</pre>
|
||
<p>
|
||
After configuring, run "<span class="command"><strong>make</strong></span>"
|
||
and "<span class="command"><strong>make test</strong></span>". If "<span class="command"><strong>make
|
||
test</strong></span>" fails with "pthread_atfork() not found", you forgot to
|
||
add the -pthread above.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.10"></a>Building OpenSSL for the SCA 6000 on Solaris</h4></div></div></div>
|
||
|
||
|
||
<p>
|
||
The SCA-6000 PKCS#11 provider is installed as a system
|
||
library, libpkcs11. It is a true crypto accelerator, up to 4
|
||
times faster than any CPU, so the flavor shall be
|
||
'crypto-accelerator'.
|
||
</p>
|
||
<p>
|
||
In this example, we are building on Solaris x86 on an
|
||
AMD64 system.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd openssl-0.9.8zc</code></strong>
|
||
$ <strong class="userinput"><code>./Configure solaris64-x86_64-cc \
|
||
--pk11-libname=/usr/lib/64/libpkcs11.so \
|
||
--pk11-flavor=crypto-accelerator \
|
||
--prefix=/opt/pkcs11/usr</code></strong>
|
||
</pre>
|
||
<p>
|
||
(For a 32-bit build, use "solaris-x86-cc" and /usr/lib/libpkcs11.so.)
|
||
</p>
|
||
<p>
|
||
After configuring, run
|
||
<span class="command"><strong>make</strong></span> and
|
||
<span class="command"><strong>make test</strong></span>.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.11"></a>Building OpenSSL for SoftHSM</h4></div></div></div>
|
||
|
||
|
||
<p>
|
||
SoftHSM (version 1) is a software library developed by the
|
||
OpenDNSSEC project
|
||
(<a class="link" href="http://www.opendnssec.org" target="_top">
|
||
http://www.opendnssec.org
|
||
</a>)
|
||
which provides a
|
||
PKCS#11 interface to a virtual HSM, implemented in the form of
|
||
a SQLite3 database on the local filesystem. SoftHSM uses
|
||
the Botan library to perform cryptographic functions. Though
|
||
less secure than a true HSM, it can allow you to experiment
|
||
with PKCS#11 when an HSM is not available.
|
||
</p>
|
||
<p>
|
||
The SoftHSM cryptographic store must be installed and
|
||
initialized before using it with OpenSSL, and the SOFTHSM_CONF
|
||
environment variable must always point to the SoftHSM configuration
|
||
file:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code> cd softhsm-1.3.7 </code></strong>
|
||
$ <strong class="userinput"><code> configure --prefix=/opt/pkcs11/usr </code></strong>
|
||
$ <strong class="userinput"><code> make </code></strong>
|
||
$ <strong class="userinput"><code> make install </code></strong>
|
||
$ <strong class="userinput"><code> export SOFTHSM_CONF=/opt/pkcs11/softhsm.conf </code></strong>
|
||
$ <strong class="userinput"><code> echo "0:/opt/pkcs11/softhsm.db" > $SOFTHSM_CONF </code></strong>
|
||
$ <strong class="userinput"><code> /opt/pkcs11/usr/bin/softhsm --init-token 0 --slot 0 --label softhsm </code></strong>
|
||
</pre>
|
||
<p>
|
||
SoftHSM can perform all cryptographic operations, but
|
||
since it only uses your system CPU, there is no advantage to using
|
||
it for anything but signing. Therefore, we choose the 'sign-only'
|
||
flavor when building OpenSSL.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd openssl-0.9.8zc</code></strong>
|
||
$ <strong class="userinput"><code>./Configure linux-x86_64 -pthread \
|
||
--pk11-libname=/opt/pkcs11/usr/lib/libsofthsm.so \
|
||
--pk11-flavor=sign-only \
|
||
--prefix=/opt/pkcs11/usr</code></strong>
|
||
</pre>
|
||
<p>
|
||
After configuring, run "<span class="command"><strong>make</strong></span>"
|
||
and "<span class="command"><strong>make test</strong></span>".
|
||
</p>
|
||
</div>
|
||
<p>
|
||
Once you have built OpenSSL, run
|
||
"<span class="command"><strong>apps/openssl engine pkcs11</strong></span>" to confirm
|
||
that PKCS#11 support was compiled in correctly. The output
|
||
should be one of the following lines, depending on the flavor
|
||
selected:
|
||
</p>
|
||
<pre class="screen">
|
||
(pkcs11) PKCS #11 engine support (sign only)
|
||
</pre>
|
||
<p>Or:</p>
|
||
<pre class="screen">
|
||
(pkcs11) PKCS #11 engine support (crypto accelerator)
|
||
</pre>
|
||
<p>
|
||
Next, run
|
||
"<span class="command"><strong>apps/openssl engine pkcs11 -t</strong></span>". This will
|
||
attempt to initialize the PKCS#11 engine. If it is able to
|
||
do so successfully, it will report
|
||
<span class="quote">“<span class="quote"><code class="literal">[ available ]</code></span>”</span>.
|
||
</p>
|
||
<p>
|
||
If the output is correct, run
|
||
"<span class="command"><strong>make install</strong></span>" which will install the
|
||
modified OpenSSL suite to <code class="filename">/opt/pkcs11/usr</code>.
|
||
</p>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.18"></a>Configuring BIND 9 for Linux with the AEP Keyper</h4></div></div></div>
|
||
|
||
|
||
<p>
|
||
To link with the PKCS#11 provider, threads must be
|
||
enabled in the BIND 9 build.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd ../bind9</code></strong>
|
||
$ <strong class="userinput"><code>./configure --enable-threads \
|
||
--with-openssl=/opt/pkcs11/usr \
|
||
--with-pkcs11=/opt/pkcs11/usr/lib/libpkcs11.so</code></strong>
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.19"></a>Configuring BIND 9 for Solaris with the SCA 6000</h4></div></div></div>
|
||
|
||
|
||
<p>
|
||
To link with the PKCS#11 provider, threads must be
|
||
enabled in the BIND 9 build.
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd ../bind9</code></strong>
|
||
$ <strong class="userinput"><code>./configure CC="cc -xarch=amd64" --enable-threads \
|
||
--with-openssl=/opt/pkcs11/usr \
|
||
--with-pkcs11=/usr/lib/64/libpkcs11.so</code></strong>
|
||
</pre>
|
||
<p>(For a 32-bit build, omit CC="cc -xarch=amd64".)</p>
|
||
<p>
|
||
If configure complains about OpenSSL not working, you
|
||
may have a 32/64-bit architecture mismatch. Or, you may have
|
||
incorrectly specified the path to OpenSSL (it should be the
|
||
same as the --prefix argument to the OpenSSL
|
||
Configure).
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h4 class="title">
|
||
<a name="id-1.5.12.8.20"></a>Configuring BIND 9 for SoftHSM</h4></div></div></div>
|
||
|
||
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>cd ../bind9</code></strong>
|
||
$ <strong class="userinput"><code>./configure --enable-threads \
|
||
--with-openssl=/opt/pkcs11/usr \
|
||
--with-pkcs11=/opt/pkcs11/usr/lib/libsofthsm.so</code></strong>
|
||
</pre>
|
||
</div>
|
||
<p>
|
||
After configuring, run
|
||
"<span class="command"><strong>make</strong></span>",
|
||
"<span class="command"><strong>make test</strong></span>" and
|
||
"<span class="command"><strong>make install</strong></span>".
|
||
</p>
|
||
<p>
|
||
(Note: If "make test" fails in the "pkcs11" system test, you may
|
||
have forgotten to set the SOFTHSM_CONF environment variable.)
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.9"></a>PKCS#11 Tools</h3></div></div></div>
|
||
|
||
<p>
|
||
BIND 9 includes a minimal set of tools to operate the
|
||
HSM, including
|
||
<span class="command"><strong>pkcs11-keygen</strong></span> to generate a new key pair
|
||
within the HSM,
|
||
<span class="command"><strong>pkcs11-list</strong></span> to list objects currently
|
||
available,
|
||
<span class="command"><strong>pkcs11-destroy</strong></span> to remove objects, and
|
||
<span class="command"><strong>pkcs11-tokens</strong></span> to list available tokens.
|
||
</p>
|
||
<p>
|
||
In UNIX/Linux builds, these tools are built only if BIND
|
||
9 is configured with the --with-pkcs11 option. (Note: If
|
||
--with-pkcs11 is set to "yes", rather than to the path of the
|
||
PKCS#11 provider, then the tools will be built but the
|
||
provider will be left undefined. Use the -m option or the
|
||
PKCS11_PROVIDER environment variable to specify the path to the
|
||
provider.)
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.10"></a>Using the HSM</h3></div></div></div>
|
||
|
||
<p>
|
||
For OpenSSL-based PKCS#11, we must first set up the runtime
|
||
environment so the OpenSSL and PKCS#11 libraries can be loaded:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>export LD_LIBRARY_PATH=/opt/pkcs11/usr/lib:${LD_LIBRARY_PATH}</code></strong>
|
||
</pre>
|
||
<p>
|
||
This causes <span class="command"><strong>named</strong></span> and other binaries to load
|
||
the OpenSSL library from <code class="filename">/opt/pkcs11/usr/lib</code>
|
||
rather than from the default location. This step is not necessary
|
||
when using native PKCS#11.
|
||
</p>
|
||
<p>
|
||
Some HSMs require other environment variables to be set.
|
||
For example, when operating an AEP Keyper, it is necessary to
|
||
specify the location of the "machine" file, which stores
|
||
information about the Keyper for use by the provider
|
||
library. If the machine file is in
|
||
<code class="filename">/opt/Keyper/PKCS11Provider/machine</code>,
|
||
use:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>export KEYPER_LIBRARY_PATH=/opt/Keyper/PKCS11Provider</code></strong>
|
||
</pre>
|
||
<p>
|
||
Such environment variables must be set whenever running
|
||
any tool that uses the HSM, including
|
||
<span class="command"><strong>pkcs11-keygen</strong></span>,
|
||
<span class="command"><strong>pkcs11-list</strong></span>,
|
||
<span class="command"><strong>pkcs11-destroy</strong></span>,
|
||
<span class="command"><strong>dnssec-keyfromlabel</strong></span>,
|
||
<span class="command"><strong>dnssec-signzone</strong></span>,
|
||
<span class="command"><strong>dnssec-keygen</strong></span>, and
|
||
<span class="command"><strong>named</strong></span>.
|
||
</p>
|
||
<p>
|
||
We can now create and use keys in the HSM. In this case,
|
||
we will create a 2048 bit key and give it the label
|
||
"sample-ksk":
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>pkcs11-keygen -b 2048 -l sample-ksk</code></strong>
|
||
</pre>
|
||
<p>To confirm that the key exists:</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>pkcs11-list</code></strong>
|
||
Enter PIN:
|
||
object[0]: handle 2147483658 class 3 label[8] 'sample-ksk' id[0]
|
||
object[1]: handle 2147483657 class 2 label[8] 'sample-ksk' id[0]
|
||
</pre>
|
||
<p>
|
||
Before using this key to sign a zone, we must create a
|
||
pair of BIND 9 key files. The "dnssec-keyfromlabel" utility
|
||
does this. In this case, we will be using the HSM key
|
||
"sample-ksk" as the key-signing key for "example.net":
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>dnssec-keyfromlabel -l sample-ksk -f KSK example.net</code></strong>
|
||
</pre>
|
||
<p>
|
||
The resulting K*.key and K*.private files can now be used
|
||
to sign the zone. Unlike normal K* files, which contain both
|
||
public and private key data, these files will contain only the
|
||
public key data, plus an identifier for the private key which
|
||
remains stored within the HSM. Signing with the private key takes
|
||
place inside the HSM.
|
||
</p>
|
||
<p>
|
||
If you wish to generate a second key in the HSM for use
|
||
as a zone-signing key, follow the same procedure above, using a
|
||
different keylabel, a smaller key size, and omitting "-f KSK"
|
||
from the dnssec-keyfromlabel arguments:
|
||
</p>
|
||
<p>
|
||
(Note: When using OpenSSL-based PKCS#11 the label is an arbitrary
|
||
string which identifies the key. With native PKCS#11, the label is
|
||
a PKCS#11 URI string which may include other details about the key
|
||
and the HSM, including its PIN. See
|
||
<a class="xref" href="man.dnssec-keyfromlabel.html" title="dnssec-keyfromlabel"><span class="refentrytitle"><span class="application">dnssec-keyfromlabel</span></span>(8)</a> for details.)
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>pkcs11-keygen -b 1024 -l sample-zsk</code></strong>
|
||
$ <strong class="userinput"><code>dnssec-keyfromlabel -l sample-zsk example.net</code></strong>
|
||
</pre>
|
||
<p>
|
||
Alternatively, you may prefer to generate a conventional
|
||
on-disk key, using dnssec-keygen:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>dnssec-keygen example.net</code></strong>
|
||
</pre>
|
||
<p>
|
||
This provides less security than an HSM key, but since
|
||
HSMs can be slow or cumbersome to use for security reasons, it
|
||
may be more efficient to reserve HSM keys for use in the less
|
||
frequent key-signing operation. The zone-signing key can be
|
||
rolled more frequently, if you wish, to compensate for a
|
||
reduction in key security. (Note: When using native PKCS#11,
|
||
there is no speed advantage to using on-disk keys, as cryptographic
|
||
operations will be done by the HSM regardless.)
|
||
</p>
|
||
<p>
|
||
Now you can sign the zone. (Note: If not using the -S
|
||
option to <span class="command"><strong>dnssec-signzone</strong></span>, it will be
|
||
necessary to add the contents of both <code class="filename">K*.key</code>
|
||
files to the zone master file before signing it.)
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>dnssec-signzone -S example.net</code></strong>
|
||
Enter PIN:
|
||
Verifying the zone using the following algorithms:
|
||
NSEC3RSASHA1.
|
||
Zone signing complete:
|
||
Algorithm: NSEC3RSASHA1: ZSKs: 1, KSKs: 1 active, 0 revoked, 0 stand-by
|
||
example.net.signed
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.11"></a>Specifying the engine on the command line</h3></div></div></div>
|
||
|
||
<p>
|
||
When using OpenSSL-based PKCS#11, the "engine" to be used by
|
||
OpenSSL can be specified in <span class="command"><strong>named</strong></span> and all of
|
||
the BIND <span class="command"><strong>dnssec-*</strong></span> tools by using the "-E
|
||
<engine>" command line option. If BIND 9 is built with
|
||
the --with-pkcs11 option, this option defaults to "pkcs11".
|
||
Specifying the engine will generally not be necessary unless
|
||
for some reason you wish to use a different OpenSSL
|
||
engine.
|
||
</p>
|
||
<p>
|
||
If you wish to disable use of the "pkcs11" engine —
|
||
for troubleshooting purposes, or because the HSM is unavailable
|
||
— set the engine to the empty string. For example:
|
||
</p>
|
||
<pre class="screen">
|
||
$ <strong class="userinput"><code>dnssec-signzone -E '' -S example.net</code></strong>
|
||
</pre>
|
||
<p>
|
||
This causes
|
||
<span class="command"><strong>dnssec-signzone</strong></span> to run as if it were compiled
|
||
without the --with-pkcs11 option.
|
||
</p>
|
||
<p>
|
||
When built with native PKCS#11 mode, the "engine" option has a
|
||
different meaning: it specifies the path to the PKCS#11 provider
|
||
library. This may be useful when testing a new provider library.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.12.12"></a>Running named with automatic zone re-signing</h3></div></div></div>
|
||
|
||
<p>
|
||
If you want <span class="command"><strong>named</strong></span> to dynamically re-sign zones
|
||
using HSM keys, and/or to to sign new records inserted via nsupdate,
|
||
then <span class="command"><strong>named</strong></span> must have access to the HSM PIN. In OpenSSL-based PKCS#11,
|
||
this is accomplished by placing the PIN into the openssl.cnf file
|
||
(in the above examples,
|
||
<code class="filename">/opt/pkcs11/usr/ssl/openssl.cnf</code>).
|
||
</p>
|
||
<p>
|
||
The location of the openssl.cnf file can be overridden by
|
||
setting the OPENSSL_CONF environment variable before running
|
||
<span class="command"><strong>named</strong></span>.
|
||
</p>
|
||
<p>Sample openssl.cnf:</p>
|
||
<pre class="programlisting">
|
||
openssl_conf = openssl_def
|
||
[ openssl_def ]
|
||
engines = engine_section
|
||
[ engine_section ]
|
||
pkcs11 = pkcs11_section
|
||
[ pkcs11_section ]
|
||
PIN = <em class="replaceable"><code><PLACE PIN HERE></code></em>
|
||
</pre>
|
||
<p>
|
||
This will also allow the dnssec-* tools to access the HSM
|
||
without PIN entry. (The pkcs11-* tools access the HSM directly,
|
||
not via OpenSSL, so a PIN will still be required to use
|
||
them.)
|
||
</p>
|
||
<p>
|
||
In native PKCS#11 mode, the PIN can be provided in a file specified
|
||
as an attribute of the key's label. For example, if a key had the label
|
||
<strong class="userinput"><code>pkcs11:object=local-zsk;pin-source=/etc/hsmpin</code></strong>,
|
||
then the PIN would be read from the file
|
||
<code class="filename">/etc/hsmpin</code>.
|
||
</p>
|
||
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
|
||
<h3 class="title">Warning</h3>
|
||
<p>
|
||
Placing the HSM's PIN in a text file in this manner may reduce the
|
||
security advantage of using an HSM. Be sure this is what you want to
|
||
do before configuring the system in this way.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="dlz-info"></a>DLZ (Dynamically Loadable Zones)</h2></div></div></div>
|
||
|
||
<p>
|
||
DLZ (Dynamically Loadable Zones) is an extension to BIND 9 that allows
|
||
zone data to be retrieved directly from an external database. There is
|
||
no required format or schema. DLZ drivers exist for several different
|
||
database backends including PostgreSQL, MySQL, and LDAP and can be
|
||
written for any other.
|
||
</p>
|
||
<p>
|
||
Historically, DLZ drivers had to be statically linked with the <span class="command"><strong>named</strong></span>
|
||
binary and were turned on via a configure option at compile time (for
|
||
example, <strong class="userinput"><code>"configure --with-dlz-ldap"</code></strong>).
|
||
Currently, the drivers provided in the BIND 9 tarball in
|
||
<code class="filename">contrib/dlz/drivers</code> are still linked this
|
||
way.
|
||
</p>
|
||
<p>
|
||
In BIND 9.8 and higher, it is possible to link some DLZ modules
|
||
dynamically at runtime, via the DLZ "dlopen" driver, which acts as a
|
||
generic wrapper around a shared object implementing the DLZ API. The
|
||
"dlopen" driver is linked into <span class="command"><strong>named</strong></span> by default, so configure options
|
||
are no longer necessary when using these dynamically linkable drivers,
|
||
but are still needed for the older drivers in
|
||
<code class="filename">contrib/dlz/drivers</code>.
|
||
</p>
|
||
|
||
<p>
|
||
When the DLZ module provides data to <span class="command"><strong>named</strong></span>, it does so in text format.
|
||
The response is converted to DNS wire format by <span class="command"><strong>named</strong></span>. This
|
||
conversion, and the lack of any internal caching, places significant
|
||
limits on the query performance of DLZ modules. Consequently, DLZ is
|
||
not recommended for use on high-volume servers. However, it can be
|
||
used in a hidden master configuration, with slaves retrieving zone
|
||
updates via AXFR. (Note, however, that DLZ has no built-in support for
|
||
DNS notify; slaves are not automatically informed of changes to the
|
||
zones in the database.)
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.13.6"></a>Configuring DLZ</h3></div></div></div>
|
||
|
||
<p>
|
||
A DLZ database is configured with a <span class="command"><strong>dlz</strong></span>
|
||
statement in <code class="filename">named.conf</code>:
|
||
</p>
|
||
<pre class="screen">
|
||
dlz example {
|
||
database "dlopen driver.so <code class="option">args</code>";
|
||
search yes;
|
||
};
|
||
</pre>
|
||
<p>
|
||
This specifies a DLZ module to search when answering queries; the
|
||
module is implemented in <code class="filename">driver.so</code> and is
|
||
loaded at runtime by the dlopen DLZ driver. Multiple
|
||
<span class="command"><strong>dlz</strong></span> statements can be specified; when
|
||
answering a query, all DLZ modules with <code class="option">search</code>
|
||
set to <code class="literal">yes</code> will be queried to find out if
|
||
they contain an answer for the query name; the best available
|
||
answer will be returned to the client.
|
||
</p>
|
||
<p>
|
||
The <code class="option">search</code> option in the above example can be
|
||
omitted, because <code class="literal">yes</code> is the default value.
|
||
</p>
|
||
<p>
|
||
If <code class="option">search</code> is set to <code class="literal">no</code>, then
|
||
this DLZ module is <span class="emphasis"><em>not</em></span> searched for the best
|
||
match when a query is received. Instead, zones in this DLZ must be
|
||
separately specified in a zone statement. This allows you to
|
||
configure a zone normally using standard zone option semantics,
|
||
but specify a different database back-end for storage of the
|
||
zone's data. For example, to implement NXDOMAIN redirection using
|
||
a DLZ module for back-end storage of redirection rules:
|
||
</p>
|
||
<pre class="screen">
|
||
dlz other {
|
||
database "dlopen driver.so <code class="option">args</code>";
|
||
search no;
|
||
};
|
||
|
||
zone "." {
|
||
type redirect;
|
||
dlz other;
|
||
};
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.13.7"></a>Sample DLZ Driver</h3></div></div></div>
|
||
|
||
<p>
|
||
For guidance in implementation of DLZ modules, the directory
|
||
<code class="filename">contrib/dlz/example</code> contains a basic
|
||
dynamically-linkable DLZ module--i.e., one which can be
|
||
loaded at runtime by the "dlopen" DLZ driver.
|
||
The example sets up a single zone, whose name is passed
|
||
to the module as an argument in the <span class="command"><strong>dlz</strong></span>
|
||
statement:
|
||
</p>
|
||
<pre class="screen">
|
||
dlz other {
|
||
database "dlopen driver.so example.nil";
|
||
};
|
||
</pre>
|
||
<p>
|
||
In the above example, the module is configured to create a zone
|
||
"example.nil", which can answer queries and AXFR requests, and
|
||
accept DDNS updates. At runtime, prior to any updates, the zone
|
||
contains an SOA, NS, and a single A record at the apex:
|
||
</p>
|
||
<pre class="screen">
|
||
example.nil. 3600 IN SOA example.nil. hostmaster.example.nil. (
|
||
123 900 600 86400 3600
|
||
)
|
||
example.nil. 3600 IN NS example.nil.
|
||
example.nil. 1800 IN A 10.53.0.1
|
||
</pre>
|
||
<p>
|
||
The sample driver is capable of retrieving information about the
|
||
querying client, and altering its response on the basis of this
|
||
information. To demonstrate this feature, the example driver
|
||
responds to queries for "source-addr.<code class="option">zonename</code>>/TXT"
|
||
with the source address of the query. Note, however, that this
|
||
record will *not* be included in AXFR or ANY responses. Normally,
|
||
this feature would be used to alter responses in some other fashion,
|
||
e.g., by providing different address records for a particular name
|
||
depending on the network from which the query arrived.
|
||
</p>
|
||
<p>
|
||
Documentation of the DLZ module API can be found in
|
||
<code class="filename">contrib/dlz/example/README</code>. This directory also
|
||
contains the header file <code class="filename">dlz_minimal.h</code>, which
|
||
defines the API and should be included by any dynamically-linkable
|
||
DLZ module.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="dyndb-info"></a>DynDB (Dynamic Database)</h2></div></div></div>
|
||
|
||
<p>
|
||
DynDB is an extension to BIND 9 which, like DLZ
|
||
(see <a class="xref" href="Bv9ARM.ch04.html#dlz-info" title="DLZ (Dynamically Loadable Zones)">the section called “DLZ (Dynamically Loadable Zones)”</a>), allows zone data to be
|
||
retrieved from an external database. Unlike DLZ, a DynDB module
|
||
provides a full-featured BIND zone database interface. Where
|
||
DLZ translates DNS queries into real-time database lookups,
|
||
resulting in relatively poor query performance, and is unable
|
||
to handle DNSSEC-signed data due to its limited API, a DynDB
|
||
module can pre-load an in-memory database from the external
|
||
data source, providing the same performance and functionality
|
||
as zones served natively by BIND.
|
||
</p>
|
||
<p>
|
||
A DynDB module supporting LDAP has been created by Red Hat
|
||
and is available from
|
||
<a class="link" href="https://fedorahosted.org/bind-dyndb-ldap/" target="_top">https://fedorahosted.org/bind-dyndb-ldap/</a>.
|
||
</p>
|
||
<p>
|
||
A sample DynDB module for testing and developer guidance
|
||
is included with the BIND source code, in the directory
|
||
<code class="filename">bin/tests/system/dyndb/driver</code>.
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.14.5"></a>Configuring DynDB</h3></div></div></div>
|
||
|
||
<p>
|
||
A DynDB database is configured with a <span class="command"><strong>dyndb</strong></span>
|
||
statement in <code class="filename">named.conf</code>:
|
||
</p>
|
||
<pre class="screen">
|
||
dyndb example "driver.so" {
|
||
<em class="replaceable"><code>parameters</code></em>
|
||
};
|
||
</pre>
|
||
<p>
|
||
The file <code class="filename">driver.so</code> is a DynDB module which
|
||
implements the full DNS database API. Multiple
|
||
<span class="command"><strong>dyndb</strong></span> statements can be specified, to load
|
||
different drivers or multiple instances of the same driver.
|
||
Zones provided by a DynDB module are added to the view's zone
|
||
table, and are treated as normal authoritative zones when BIND
|
||
is responding to queries. Zone configuration is handled internally
|
||
by the DynDB module.
|
||
</p>
|
||
<p>
|
||
The <em class="replaceable"><code>parameters</code></em> are passed as an opaque
|
||
string to the DynDB module's initialization routine. Configuration
|
||
syntax will differ depending on the driver.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.14.6"></a>Sample DynDB Module</h3></div></div></div>
|
||
|
||
<p>
|
||
For guidance in implementation of DynDB modules, the directory
|
||
<code class="filename">bin/tests/system/dyndb/driver</code>.
|
||
contains a basic DynDB module.
|
||
The example sets up two zones, whose names are passed
|
||
to the module as arguments in the <span class="command"><strong>dyndb</strong></span>
|
||
statement:
|
||
</p>
|
||
<pre class="screen">
|
||
dyndb sample "sample.so" { example.nil. arpa. };
|
||
</pre>
|
||
<p>
|
||
In the above example, the module is configured to create a zone
|
||
"example.nil", which can answer queries and AXFR requests, and
|
||
accept DDNS updates. At runtime, prior to any updates, the zone
|
||
contains an SOA, NS, and a single A record at the apex:
|
||
</p>
|
||
<pre class="screen">
|
||
example.nil. 86400 IN SOA example.nil. example.nil. (
|
||
0 28800 7200 604800 86400
|
||
)
|
||
example.nil. 86400 IN NS example.nil.
|
||
example.nil. 86400 IN A 127.0.0.1
|
||
</pre>
|
||
<p>
|
||
When the zone is updated dynamically, the DynDB module will determine
|
||
whether the updated RR is an address (i.e., type A or AAAA) and if
|
||
so, it will automatically update the corresponding PTR record in a
|
||
reverse zone. (Updates are not stored permanently; all updates are
|
||
lost when the server is restarted.)
|
||
</p>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="catz-info"></a>Catalog Zones</h2></div></div></div>
|
||
|
||
<p>
|
||
A "catalog zone" is a special DNS zone that contains a list of
|
||
other zones to be served, along with their configuration parameters.
|
||
Zones listed in a catalog zone are called "member zones".
|
||
When a catalog zone is loaded or transferred to a slave server
|
||
which supports this functionality, the slave server will create
|
||
the member zones automatically. When the catalog zone is updated
|
||
(for example, to add or delete member zones, or change
|
||
their configuration parameters) those changes are immediately put
|
||
into effect. Because the catalog zone is a normal DNS zone, these
|
||
configuration changes can be propagated using the standard AXFR/IXFR
|
||
zone transfer mechanism.
|
||
</p>
|
||
<p>
|
||
Catalog zones' format and behavior are specified as an internet draft
|
||
for interoperability among DNS implementations. As of this release, the
|
||
latest revision of the DNS catalog zones draft can be found here:
|
||
https://datatracker.ietf.org/doc/draft-muks-dnsop-dns-catalog-zones/
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.15.4"></a>Principle of Operation</h3></div></div></div>
|
||
<p>
|
||
Normally, if a zone is to be served by a slave server, the
|
||
<code class="filename">named.conf</code> file on the server must list the
|
||
zone, or the zone must be added using <span class="command"><strong>rndc addzone</strong></span>.
|
||
In environments with a large number of slave servers and/or where
|
||
the zones being served are changing frequently, the overhead involved
|
||
in maintaining consistent zone configuration on all the slave
|
||
servers can be significant.
|
||
</p>
|
||
<p>
|
||
A catalog zone is a way to ease this administrative burden. It is a
|
||
DNS zone that lists member zones that should be served by slave servers.
|
||
When a slave server receives an update to the catalog zone, it adds,
|
||
removes, or reconfigures member zones based on the data received.
|
||
</p>
|
||
<p>
|
||
To use a catalog zone, it must first be set up as a normal zone on
|
||
the master and the on slave servers that will be configured to use
|
||
it. It must also be added to a <code class="option">catalog-zones</code> list
|
||
in the <code class="option">options</code> or <code class="option">view</code> statement
|
||
in <code class="filename">named.conf</code>. (This is comparable to the way
|
||
a policy zone is configured as a normal zone and also listed in
|
||
a <code class="option">response-policy</code> statement.)
|
||
</p>
|
||
<p>
|
||
To use the catalog zone feature to serve a new member zone:
|
||
</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
<p>
|
||
Set up the the member zone to be served on the master as normal.
|
||
This could be done by editing <code class="filename">named.conf</code>,
|
||
or by running <span class="command"><strong>rndc addzone</strong></span>.
|
||
</p>
|
||
</li>
|
||
<li class="listitem">
|
||
<p>
|
||
Add an entry to the catalog zone for the new member zone.
|
||
This could be done by editing the catalog zone's master file
|
||
and running <span class="command"><strong>rndc reload</strong></span>, or by updating
|
||
the zone using <span class="command"><strong>nsupdate</strong></span>.
|
||
</p>
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
The change to the catalog zone will be propagated from the master to all
|
||
slaves using the normal AXFR/IXFR mechanism. When the slave receives the
|
||
update to the catalog zone, it will detect the entry for the new member
|
||
zone, create an instance of of that zone on the slave server, and point
|
||
that instance to the <code class="option">masters</code> specified in the catalog
|
||
zone data. The newly created member zone is a normal slave zone, so
|
||
BIND will immediately initiate a transfer of zone contents from the
|
||
master. Once complete, the slave will start serving the member zone.
|
||
</p>
|
||
<p>
|
||
Removing a member zone from a slave server requires nothing more than
|
||
deleting the member zone's entry in the catalog zone. The change to the
|
||
catalog zone is propagated to the slave server using the normal AXFR/IXFR
|
||
transfer mechanism. The slave server, on processing the update, will
|
||
notice that the member zone has been removed. It will stop serving the
|
||
zone and remove it from its list of configured zones. (Removing the
|
||
member zone from the master server has to be done in the normal way,
|
||
by editing the configuration file or running
|
||
<span class="command"><strong>rndc delzone</strong></span>.)
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.15.5"></a>Configuring Catalog Zones</h3></div></div></div>
|
||
<p>
|
||
Catalog zones are configured with a <span class="command"><strong>catalog-zones</strong></span>
|
||
statement in the <code class="literal">options</code> or <code class="literal">view</code>
|
||
section of <code class="filename">named.conf</code>. For example,
|
||
</p>
|
||
<pre class="screen">
|
||
catalog-zones {
|
||
zone "catalog.example"
|
||
default-masters { 10.53.0.1; }
|
||
in-memory no
|
||
zone-directory "catzones"
|
||
min-update-interval 10;
|
||
};
|
||
</pre>
|
||
<p>
|
||
This statement specifies that the zone
|
||
<code class="literal">catalog.example</code> is a catalog zone. This zone must be
|
||
properly configured in the same view. In most configurations, it would
|
||
be a slave zone.
|
||
</p>
|
||
<p>
|
||
The options following the zone name are not required, and may be
|
||
specified in any order:
|
||
</p>
|
||
<p>
|
||
The <code class="option">default-masters</code> option defines the default masters
|
||
for member zones listed in a catalog zone. This can be overridden by
|
||
options within a catalog zone. If no such options are included, then
|
||
member zones will transfer their contents from the servers listed in
|
||
this option.
|
||
</p>
|
||
<p>
|
||
The <code class="option">in-memory</code> option, if set to <code class="literal">yes</code>,
|
||
causes member zones to be stored only in memory. This is functionally
|
||
equivalent to configuring a slave zone without a <code class="option">file</code>.
|
||
option. The default is <code class="literal">no</code>; member zones' content
|
||
will be stored locally in a file whose name is automatically generated
|
||
from the view name, catalog zone name, and member zone name.
|
||
</p>
|
||
<p>
|
||
The <code class="option">zone-directory</code> option causes local copies of
|
||
member zones' master files (if <code class="option">in-memory</code> is not set
|
||
to <code class="literal">yes</code>) to be stored in the specified directory.
|
||
The default is to store zone files in the server's working directory.
|
||
A non-absolute pathname in <code class="option">zone-directory</code> is
|
||
assumed to be relative to the working directory.
|
||
</p>
|
||
<p>
|
||
The <code class="option">min-update-interval</code> option sets the minimum
|
||
interval between processing of updates to catalog zones, in seconds.
|
||
If an update to a catalog zone (for example, via IXFR) happens less
|
||
than <code class="option">min-update-interval</code> seconds after the most
|
||
recent update, then the changes will not be carried out until this
|
||
interval has elapsed. The default is <code class="literal">5</code> seconds.
|
||
</p>
|
||
<p>
|
||
Catalog zones are defined on a per-view basis. Configuring a non-empty
|
||
<code class="option">catalog-zones</code> statement in a view will automatically
|
||
turn on <code class="option">allow-new-zones</code> for that view. (Note: this
|
||
means <span class="command"><strong>rndc addzone</strong></span> and <span class="command"><strong>rndc delzone</strong></span>
|
||
will also work in any view that supports catalog zones.)
|
||
</p>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.15.6"></a>Catalog Zone format</h3></div></div></div>
|
||
<p>
|
||
A catalog zone is a regular DNS zone; therefore, it has to have a
|
||
single <code class="literal">SOA</code> and at least one <code class="literal">NS</code>
|
||
record.
|
||
</p>
|
||
<p>
|
||
A record stating the version of the catalog zone format is
|
||
also required. If the version number listed is not supported by
|
||
the server, then a catalog zone may not be used by that server.
|
||
</p>
|
||
<pre class="screen">
|
||
catalog.example. IN SOA . . 2016022901 900 600 86400 1
|
||
catalog.example. IN NS nsexample.
|
||
version.catalog.example. IN TXT "1"
|
||
</pre>
|
||
<p>
|
||
Note that this record must have the domain name
|
||
version.<em class="replaceable"><code>catalog-zone-name</code></em>. This illustrates
|
||
how the meaning of data stored in a catalog zone is indicated by the
|
||
the domain name label immediately before the catalog zone domain.
|
||
</p>
|
||
<p>
|
||
Catalog zone options can be set either globally for the whole catalog
|
||
zone or for a single member zone. Global options override the settings
|
||
in the configuration file and member zone options override global
|
||
options.
|
||
</p>
|
||
<p>
|
||
Global options are set at the apex of the catalog zone, e.g.:
|
||
</p>
|
||
<pre class="screen">
|
||
masters.catalog.example. IN AAAA 2001:db8::1
|
||
</pre>
|
||
<p>BIND currently supports the following options:</p>
|
||
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
|
||
<li class="listitem">
|
||
<p>A simple <code class="option">masters</code> definition:</p>
|
||
<pre class="screen">
|
||
masters.catalog.example. IN A 192.0.2.1
|
||
</pre>
|
||
<p>
|
||
This option defines a master server for the member zones - it
|
||
can be either an A or AAAA record. If multiple masters are set the
|
||
order in which they are used is random.
|
||
</p>
|
||
</li>
|
||
<li class="listitem">
|
||
<p>A <code class="option">masters</code> with a TSIG key defined:</p>
|
||
<pre class="screen">
|
||
label.masters.catalog.example. IN A 192.0.2.2
|
||
label.masters.catalog.example. IN TXT "tsig_key_name"
|
||
</pre>
|
||
<p>
|
||
This option defines a master server for the member zone with a TSIG
|
||
key set. The TSIG key must be configured in the configuration file.
|
||
<code class="option">label</code> can be any valid DNS label.
|
||
</p>
|
||
</li>
|
||
<li class="listitem">
|
||
<p><code class="option">allow-query</code> and
|
||
<code class="option">allow-transfer</code> ACLs:</p>
|
||
<pre class="screen">
|
||
allow-query.catalog.example. IN APL 1:10.0.0.1/24
|
||
allow-transfer.catalog.example. IN APL !1:10.0.0.1/32 1:10.0.0.0/24
|
||
</pre>
|
||
<p>
|
||
These options are the equivalents of <code class="option">allow-query</code>
|
||
and <code class="option">allow-transfer</code> in a zone declaration in the
|
||
<code class="filename">named.conf</code> configuration file. The ACL is
|
||
processed in order - if there's no match to any rule the default
|
||
policy is to deny access. For the syntax of the APL RR see RFC
|
||
3123
|
||
</p>
|
||
</li>
|
||
</ul></div>
|
||
<p>
|
||
A member zone is added by including a <code class="literal">PTR</code>
|
||
resource record in the <code class="literal">zones</code> sub-domain of the
|
||
catalog zone. The record label is a <code class="literal">SHA-1</code> hash
|
||
of the member zone name in wire format. The target of the PTR
|
||
record is the member zone name. For example, to add the member
|
||
zone <code class="literal">domain.example</code>:
|
||
</p>
|
||
<pre class="screen">
|
||
5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN PTR domain.example.
|
||
</pre>
|
||
<p>
|
||
The hash is necessary to identify options for a specific member
|
||
zone. The member zone-specific options are defined the same way as
|
||
global options, but in the member zone subdomain:
|
||
</p>
|
||
<pre class="screen">
|
||
masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN A 192.0.2.2
|
||
label.masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN AAAA 2001:db8::2
|
||
label.masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN TXT "tsig_key"
|
||
allow-query.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN APL 1:10.0.0.0/24
|
||
</pre>
|
||
<p>
|
||
As would be expected, options defined for a specific zone override
|
||
the global options defined in the catalog zone. These in turn override
|
||
the global options defined in the <code class="literal">catalog-zones</code>
|
||
statement in the configuration file.
|
||
</p>
|
||
<p>
|
||
(Note that none of the global records an option will be inherited if
|
||
any records are defined for that option for the specific zone. For
|
||
example, if the zone had a <code class="literal">masters</code> record of type
|
||
A but not AAAA, then it would <span class="emphasis"><em>not</em></span> inherit the
|
||
type AAAA record from the global option.)
|
||
</p>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
|
||
<a name="ipv6"></a>IPv6 Support in <acronym class="acronym">BIND</acronym> 9</h2></div></div></div>
|
||
<p>
|
||
<acronym class="acronym">BIND</acronym> 9 fully supports all currently
|
||
defined forms of IPv6 name to address and address to name
|
||
lookups. It will also use IPv6 addresses to make queries when
|
||
running on an IPv6 capable system.
|
||
</p>
|
||
|
||
<p>
|
||
For forward lookups, <acronym class="acronym">BIND</acronym> 9 supports
|
||
only AAAA records. RFC 3363 deprecated the use of A6 records,
|
||
and client-side support for A6 records was accordingly removed
|
||
from <acronym class="acronym">BIND</acronym> 9.
|
||
However, authoritative <acronym class="acronym">BIND</acronym> 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.
|
||
</p>
|
||
|
||
<p>
|
||
For IPv6 reverse lookups, <acronym class="acronym">BIND</acronym> 9 supports
|
||
the traditional "nibble" format used in the
|
||
<span class="emphasis"><em>ip6.arpa</em></span> domain, as well as the older, deprecated
|
||
<span class="emphasis"><em>ip6.int</em></span> domain.
|
||
Older versions of <acronym class="acronym">BIND</acronym> 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 <acronym class="acronym">BIND</acronym> 9 do not understand
|
||
the binary label format at all any more, and will return an
|
||
error if given.
|
||
In particular, an authoritative <acronym class="acronym">BIND</acronym> 9
|
||
name server will not load a zone file containing binary labels.
|
||
</p>
|
||
|
||
<p>
|
||
For an overview of the format and structure of IPv6 addresses,
|
||
see <a class="xref" href="Bv9ARM.ch11.html#ipv6addresses" title="IPv6 addresses (AAAA)">the section called “IPv6 addresses (AAAA)”</a>.
|
||
</p>
|
||
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.16.6"></a>Address Lookups Using AAAA Records</h3></div></div></div>
|
||
|
||
<p>
|
||
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,
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
$ORIGIN example.com.
|
||
host 3600 IN AAAA 2001:db8::1
|
||
</pre>
|
||
|
||
<p>
|
||
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 <code class="literal">::ffff:192.168.42.1</code> as
|
||
the address.
|
||
</p>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="id-1.5.16.7"></a>Address to Name Lookups Using Nibble Format</h3></div></div></div>
|
||
|
||
<p>
|
||
When looking up an address in nibble format, the address
|
||
components are simply reversed, just as in IPv4, and
|
||
<code class="literal">ip6.arpa.</code> is appended to the
|
||
resulting name.
|
||
For example, the following would provide reverse name lookup for
|
||
a host with address
|
||
<code class="literal">2001:db8::1</code>.
|
||
</p>
|
||
|
||
<pre class="programlisting">
|
||
$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. )
|
||
</pre>
|
||
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<div class="navfooter">
|
||
<hr>
|
||
<table width="100%" summary="Navigation footer">
|
||
<tr>
|
||
<td width="40%" align="left">
|
||
<a accesskey="p" href="Bv9ARM.ch03.html">Prev</a> </td>
|
||
<td width="20%" align="center"> </td>
|
||
<td width="40%" align="right"> <a accesskey="n" href="Bv9ARM.ch05.html">Next</a>
|
||
</td>
|
||
</tr>
|
||
<tr>
|
||
<td width="40%" align="left" valign="top">Chapter 3. Name Server Configuration </td>
|
||
<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td>
|
||
<td width="40%" align="right" valign="top"> Chapter 5. The <acronym class="acronym">BIND</acronym> 9 Lightweight Resolver</td>
|
||
</tr>
|
||
</table>
|
||
</div>
|
||
<p xmlns:db="http://docbook.org/ns/docbook" style="text-align: center;">BIND 9.11.3 (Extended Support Version)</p>
|
||
</body>
|
||
</html>
|