391 lines
17 KiB
XML
391 lines
17 KiB
XML
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
|
|
[<!ENTITY mdash "—">]>
|
|
<!--
|
|
- Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
|
|
-
|
|
- Permission to use, copy, modify, and/or distribute this software for any
|
|
- purpose with or without fee is hereby granted, provided that the above
|
|
- copyright notice and this permission notice appear in all copies.
|
|
-
|
|
- THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
|
|
- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
- AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
|
|
- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
|
- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
|
|
- OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
|
- PERFORMANCE OF THIS SOFTWARE.
|
|
-->
|
|
|
|
<!-- $Id: pkcs11.xml,v 1.3 2010-02-06 07:42:02 marka Exp $ -->
|
|
|
|
<sect1 id="pkcs11">
|
|
<title>PKCS #11 (Cryptoki) support</title>
|
|
<para>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.</para>
|
|
<para>BIND 9 is known to work with two HSMs: The Sun SCA 6000
|
|
cryptographic acceleration board, tested under Solaris x86, and
|
|
the AEP Keyper network-attached key storage device, tested with
|
|
Debian Linux, Solaris x86 and Windows Server 2003.</para>
|
|
<sect2>
|
|
<title>Prerequisites</title>
|
|
<para>See the HSM vendor documentation for information about
|
|
installing, initializing, testing and troubleshooting the
|
|
HSM.</para>
|
|
<para>BIND 9 uses OpenSSL for cryptography, but stock OpenSSL
|
|
does not yet fully support PKCS #11. However, a PKCS #11 engine
|
|
for OpenSSL is available from the OpenSolaris project. It has
|
|
been modified by ISC to work with with BIND 9, and to provide
|
|
new features such as PIN management and key by
|
|
reference.</para>
|
|
<para>The patched OpenSSL depends on a "PKCS #11 provider".
|
|
This is a shared library object, providing a low-level PKCS #11
|
|
interface to the HSM hardware. It is dynamically loaded by
|
|
OpenSSL at runtime. The PKCS #11 provider comes from the HSM
|
|
vendor, and and is specific to the HSM to be controlled.</para>
|
|
<para>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:</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>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.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>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.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
<para>The modified OpenSSL code is included in the BIND 9.7.0
|
|
release, in the form of a context diff against the latest OpenSSL.
|
|
</para>
|
|
<note>
|
|
The latest OpenSSL version at the time of the BIND release
|
|
is 0.9.8l.
|
|
ISC will provide an updated patch as new versions of OpenSSL
|
|
are released. The version number in the following examples
|
|
is expected to change.</note>
|
|
<para>
|
|
Before building BIND 9 with PKCS #11 support, it will be
|
|
necessary to build OpenSSL with this patch in place and inform
|
|
it of the path to the HSM-specific PKCS #11 provider
|
|
library.</para>
|
|
<para>Obtain OpenSSL 0.9.8l:</para>
|
|
<screen>
|
|
$ <userinput>wget <ulink>http://www.openssl.org/source/openssl-0.9.8l.tar.gz</ulink></userinput>
|
|
</screen>
|
|
<para>Extract the tarball:</para>
|
|
<screen>
|
|
$ <userinput>tar zxf openssl-0.9.8l.tar.gz</userinput>
|
|
</screen>
|
|
<para>Apply the patch from the BIND 9 release:</para>
|
|
<screen>
|
|
$ <userinput>patch -p1 -d openssl-0.9.8l \
|
|
< bind-9.7.0/bin/pkcs11/openssl-0.9.8l-patch</userinput>
|
|
</screen>
|
|
<note>(Note that the patch file may not be compatible with the
|
|
"patch" utility on all operating systems. You may need to
|
|
install GNU patch.)</note>
|
|
<para>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.</para>
|
|
<sect3>
|
|
<!-- Example 1 -->
|
|
<title>Building OpenSSL for the AEP Keyper on Linux</title>
|
|
<para>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.</para>
|
|
<para>The Keyper-specific PKCS #11 provider library is
|
|
delivered with the Keyper software. In this example, we place
|
|
it /opt/pkcs11/usr/lib:</para>
|
|
<screen>
|
|
$ <userinput>cp pkcs11.GCC4.0.2.so.4.05 /opt/pkcs11/usr/lib/libpkcs11.so</userinput>
|
|
</screen>
|
|
<para>This library is only available for Linux as a 32-bit
|
|
binary. If we are compiling on a 64-bit Linux system, it is
|
|
necessary to force a 32-bit build, by specifying -m32 in the
|
|
build options.</para>
|
|
<para>Finally, the Keyper library requires threads, so we
|
|
must specify -pthread.</para>
|
|
<screen>
|
|
$ <userinput>cd openssl-0.9.8l</userinput>
|
|
$ <userinput>./Configure linux-generic32 -m32 -pthread \
|
|
--pk11-libname=/opt/pkcs11/usr/lib/libpkcs11.so \
|
|
--pk11-flavor=sign-only \
|
|
--prefix=/opt/pkcs11/usr</userinput>
|
|
</screen>
|
|
<para>After configuring, run "<command>make</command>"
|
|
and "<command>make test</command>". If "<command>make
|
|
test</command>" fails with "pthread_atfork() not found", you forgot to
|
|
add the -pthread above.</para>
|
|
</sect3>
|
|
<sect3>
|
|
<!-- Example 2 -->
|
|
<title>Building OpenSSL for the SCA 6000 on Solaris</title>
|
|
<para>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'.</para>
|
|
<para>In this example, we are building on Solaris x86 on an
|
|
AMD64 system.</para>
|
|
<screen>
|
|
$ <userinput>cd openssl-0.9.8l</userinput>
|
|
$ <userinput>./Configure solaris64-x86_64-cc \
|
|
--pk11-libname=/usr/lib/64/libpkcs11.so \
|
|
--pk11-flavor=crypto-accelerator \
|
|
--prefix=/opt/pkcs11/usr</userinput>
|
|
</screen>
|
|
<para>(For a 32-bit build, use "solaris-x86-cc" and
|
|
/usr/lib/libpkcs11.so.)</para>
|
|
<para>After configuring, run
|
|
<command>make</command> and
|
|
<command>make test</command>.</para>
|
|
<para>Once you have built OpenSSL, run
|
|
"<command>apps/openssl engine pkcs11</command>" to confirm
|
|
that PKCS #11 support was compiled in correctly. The output
|
|
should be one of the following lines, depending on the flavor
|
|
selected:</para>
|
|
<screen>
|
|
(pkcs11) PKCS #11 engine support (sign only)
|
|
</screen>
|
|
<para>Or:</para>
|
|
<screen>
|
|
(pkcs11) PKCS #11 engine support (crypto accelerator)
|
|
</screen>
|
|
<para>Next, run
|
|
"<command>apps/openssl engine pkcs11 -t</command>". This will
|
|
attempt to initialize the PKCS #11 engine. If it is able to
|
|
do so successfully, it will report
|
|
<quote><literal>[ available ]</literal></quote>.</para>
|
|
<para>If the output is correct, run
|
|
"<command>make install</command>" which will install the
|
|
modified OpenSSL suite to
|
|
<filename>/opt/pkcs11/usr</filename>.</para>
|
|
</sect3>
|
|
</sect2>
|
|
<sect2>
|
|
<title>Building BIND 9 with PKCS#11</title>
|
|
<para>When building BIND 9, the location of the custom-built
|
|
OpenSSL library must be specified via configure.</para>
|
|
<sect3>
|
|
<!-- Example 3 -->
|
|
<title>Configuring BIND 9 for Linux</title>
|
|
<para>To link with the PKCS #11 provider, threads must be
|
|
enabled in the BIND 9 build.</para>
|
|
<para>The PKCS #11 library for the AEP Keyper is currently
|
|
only available as a 32-bit binary. If we are building on a
|
|
64-bit host, we must force a 32-bit build by adding "-m32" to
|
|
the CC options on the "configure" command line.</para>
|
|
<screen>
|
|
$ <userinput>cd ../bind-9.7.0</userinput>
|
|
$ <userinput>./configure CC="gcc -m32" --enable-threads \
|
|
--with-openssl=/opt/pkcs11/usr \
|
|
--with-pkcs11=/opt/pkcs11/usr/lib/libpkcs11.so</userinput>
|
|
</screen>
|
|
</sect3>
|
|
<sect3>
|
|
<!-- Example 4 -->
|
|
<title>Configuring BIND 9 for Solaris</title>
|
|
<para>To link with the PKCS #11 provider, threads must be
|
|
enabled in the BIND 9 build.</para>
|
|
<screen>
|
|
$ <userinput>cd ../bind-9.7.0</userinput>
|
|
$ <userinput>./configure CC="cc -xarch=amd64" --enable-threads \
|
|
--with-openssl=/opt/pkcs11/usr \
|
|
--with-pkcs11=/usr/lib/64/libpkcs11.so</userinput>
|
|
</screen>
|
|
<para>(For a 32-bit build, omit CC="cc -xarch=amd64".)</para>
|
|
<para>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).</para>
|
|
</sect3>
|
|
<para>After configuring, run
|
|
"<command>make</command>",
|
|
"<command>make test</command>" and
|
|
"<command>make install</command>".</para>
|
|
</sect2>
|
|
<sect2>
|
|
<title>PKCS #11 Tools</title>
|
|
<para>BIND 9 includes a minimal set of tools to operate the
|
|
HSM, including
|
|
<command>pkcs11-keygen</command> to generate a new key pair
|
|
within the HSM,
|
|
<command>pkcs11-list</command> to list objects currently
|
|
available, and
|
|
<command>pkcs11-destroy</command> to remove objects.</para>
|
|
<para>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.)</para>
|
|
</sect2>
|
|
<sect2>
|
|
<title>Using the HSM</title>
|
|
<para>First, we must set up the runtime environment so the
|
|
OpenSSL and PKCS #11 libraries can be loaded:</para>
|
|
<screen>
|
|
$ <userinput>export LD_LIBRARY_PATH=/opt/pkcs11/usr/lib:${LD_LIBRARY_PATH}</userinput>
|
|
</screen>
|
|
<para>When operating an AEP Keyper, it is also necessary to
|
|
specify the location of the "machine" file, which stores
|
|
information about the Keyper for use by PKCS #11 provider
|
|
library. If the machine file is in
|
|
<filename>/opt/Keyper/PKCS11Provider/machine</filename>,
|
|
use:</para>
|
|
<screen>
|
|
$ <userinput>export KEYPER_LIBRARY_PATH=/opt/Keyper/PKCS11Provider</userinput>
|
|
</screen>
|
|
<!-- TODO: why not defined at compile time? -->
|
|
<para>These environment variables must be set whenever running
|
|
any tool that uses the HSM, including
|
|
<command>pkcs11-keygen</command>,
|
|
<command>pkcs11-list</command>,
|
|
<command>pkcs11-destroy</command>,
|
|
<command>dnssec-keyfromlabel</command>,
|
|
<command>dnssec-signzone</command>,
|
|
<command>dnssec-keygen</command>(which will use the HSM for
|
|
random number generation), and
|
|
<command>named</command>.</para>
|
|
<para>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":</para>
|
|
<screen>
|
|
$ <userinput>pkcs11-keygen -b 2048 -l sample-ksk</userinput>
|
|
</screen>
|
|
<para>To confirm that the key exists:</para>
|
|
<screen>
|
|
$ <userinput>pkcs11-list</userinput>
|
|
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]
|
|
</screen>
|
|
<para>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":</para>
|
|
<screen>
|
|
$ <userinput>dnssec-keyfromlabel -l sample-ksk -f KSK example.net</userinput>
|
|
</screen>
|
|
<para>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. The HSM handles signing with the
|
|
private key.</para>
|
|
<para>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:</para>
|
|
<screen>
|
|
$ <userinput>pkcs11-keygen -b 1024 -l sample-zsk</userinput>
|
|
$ <userinput>dnssec-keyfromlabel -l sample-zsk example.net</userinput>
|
|
</screen>
|
|
<para>Alternatively, you may prefer to generate a conventional
|
|
on-disk key, using dnssec-keygen:</para>
|
|
<screen>
|
|
$ <userinput>dnssec-keygen example.net</userinput>
|
|
</screen>
|
|
<para>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.</para>
|
|
<para>Now you can sign the zone. (Note: If not using the -S
|
|
option to
|
|
<command>dnssec-signzone</command>, it will be necessary to add
|
|
the contents of both
|
|
<filename>K*.key</filename> files to the zone master file before
|
|
signing it.)</para>
|
|
<screen>
|
|
$ <userinput>dnssec-signzone -S example.net</userinput>
|
|
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
|
|
</screen>
|
|
</sect2>
|
|
<sect2>
|
|
<title>Specifying the engine on the command line</title>
|
|
<para>The OpenSSL engine can be specified in
|
|
<command>named</command> and all of the BIND
|
|
<command>dnssec-*</command> 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.</para>
|
|
<para>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:</para>
|
|
<screen>
|
|
$ <userinput>dnssec-signzone -E '' -S example.net</userinput>
|
|
</screen>
|
|
<para>This causes
|
|
<command>dnssec-signzone</command> to run as if it were compiled
|
|
without the --with-pkcs11 option.</para>
|
|
</sect2>
|
|
<sect2>
|
|
<title>Running named with automatic zone re-signing</title>
|
|
<para>If you want
|
|
<command>named</command> to dynamically re-sign zones using HSM
|
|
keys, and/or to to sign new records inserted via nsupdate, then
|
|
named must have access to the HSM PIN. This can be accomplished
|
|
by placing the PIN into the openssl.cnf file (in the above
|
|
examples,
|
|
<filename>/opt/pkcs11/usr/ssl/openssl.cnf</filename>).</para>
|
|
<para>The location of the openssl.cnf file can be overridden by
|
|
setting the OPENSSL_CONF environment variable before running
|
|
named.</para>
|
|
<para>Sample openssl.cnf:</para>
|
|
<programlisting>
|
|
openssl_conf = openssl_def
|
|
[ openssl_def ]
|
|
engines = engine_section
|
|
[ engine_section ]
|
|
pkcs11 = pkcs11_section
|
|
[ pkcs11_section ]
|
|
PIN = <replaceable><PLACE PIN HERE></replaceable>
|
|
</programlisting>
|
|
<para>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.)</para>
|
|
<!--
|
|
If the PIN is not known, I believe the first time named needs the
|
|
PIN to open a key, it'll ask you to type in the PIN, which will be
|
|
a problem because it probably won't be running on a terminal
|
|
-->
|
|
<warning>
|
|
<para>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
|
|
OpenSSL in this way.</para>
|
|
</warning>
|
|
</sect2>
|
|
<!-- TODO: what is alternative then for named dynamic re-signing? -->
|
|
<!-- TODO: what happens if PIN is not known? named will log about it? -->
|
|
</sect1>
|