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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<refentry>
<refmeta>
<refentrytitle>IPSEC-ECDSASIGKEY</refentrytitle>
<manvolnum>8</manvolnum>
<refmiscinfo class='date'>6 Sep 2013</refmiscinfo>
<refmiscinfo class="source">Libreswan</refmiscinfo>
<refmiscinfo class="version">@@IPSECVERSION@@</refmiscinfo>
<refmiscinfo class="manual">Executable programs</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>ipsec-ecdsasigkey</refname>
<refpurpose>generate ECDSA signature key</refpurpose>
</refnamediv>
<!-- body begins here -->
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>ipsec ecdsasigkey</command>
<arg choice='opt'>--verbose </arg>
<arg choice='opt'>--seeddev <replaceable>device</replaceable></arg>
<arg choice='opt'>--seed <replaceable>numbits</replaceable></arg>
<arg choice='opt'>--nssdir <replaceable>nssdir</replaceable></arg>
<arg choice='opt'>--password <replaceable>nsspassword</replaceable></arg>
<arg choice='opt'>--hostname <replaceable>hostname</replaceable></arg>
<arg choice='opt'>curvename</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
<command>ecdsasigkey</command>
generates an ECDSA public/private key pair, suitable for digital signatures, on a named curve specified with
<emphasis>curvename</emphasis>. Currently it only accepts <emphasis>secp256r1</emphasis>,
<emphasis>secp384r1</emphasis>, and <emphasis>secp521r1</emphasis>.
</para>
<para>
The public exponent is forced to the value <emphasis>3</emphasis>, which has important
speed advantages for signature checking. Beware that the resulting keys
have known weaknesses as encryption keys
<emphasis>and should not be used for that purpose</emphasis>.
</para>
<para>
The <option>--verbose</option> option makes <emphasis>ecdsasigkey</emphasis>
give a running commentary on standard error. By default, it works in
silence until it is ready to generate output.
</para>
<para>
The <option>--seeddev</option> option specifies a
source for random bits used to seed the crypto library's
RNG. The default is <filename>/dev/random</filename> (see
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>).
FreeS/WAN and Openswan without NSS support used this option to specify
the random source used to directly create keys. Libreswan only uses
it to seed the NSS crypto libraries RNG. Under Linux with hardware random
support, special devices might show up as <filename>/dev/*rng*</filename>
devices. However, these should never be accessed directly using this option,
as hardware failures could lead to extremely non-random values (streams
of zeroes have been observed in the wild)
</para>
<para>
The <option>--seedbits</option> option specifies how many seed bits are pulled from
the random device to seed the NSS PRNG. The default of 480bit comes from FIPS requirements.
Seed bits are rounded up to a multiple of 8.
</para>
<para>
The use of a different random device or a reduction of seedbits from the default value is
prevented when the system is running in FIPS mode.
</para>
<para>
The <option>--nssdir</option> option specifies the directory to use for the nss database.
This is the directory where the NSS certificate, key and security modules databases reside. The
default value is <filename>@@IPSEC_NSSDIR@@</filename>.
</para>
<para>
The <option>--password</option> option specifies the nss cryptographic module authentication
password if the NSS module has been configured to require it. A password is required by hardware
tokens and also by the internal software token module when configured to run in FIPS mode.
If the argument is <emphasis>@@IPSEC_CONFDDIR@@</emphasis><filename>/nsspassword</filename>,
the password comes from that file; otherwise argument is the password.
</para>
</refsect1>
<refsect1 id='examples'><title>EXAMPLES</title>
<variablelist>
<varlistentry>
<term>
<command>ipsec ecdsasigkey --verbose 4096</command>
</term>
<listitem>
<para>generates a 4096-bit signature key and stores this key in the NSS database.
The public key can then be extracted and edited into the <filename>ipsec.conf</filename> (see
<citerefentry><refentrytitle>ipsec-showhostkey</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<para>
/dev/random, /dev/urandom
</para>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>rngd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>ipsec-showhostkey</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<emphasis>Applied Cryptography, 2nd. ed., by Bruce Schneier, Wiley 1996</emphasis>,
<emphasis>RFCs 2537, 2313</emphasis>,
<emphasis>GNU MP, the GNU multiple precision arithmetic library, edition 2.0.2, by Torbj Granlund</emphasis>
</para>
</refsect1>
<refsect1 id='history'>
<title>HISTORY</title>
<para>
Originally written for the Linux FreeS/WAN project
<<ulink url='https://www.freeswan.org'>https://www.freeswan.org</ulink>>
by Henry Spencer. Updated for the Libreswan Project by Paul Wouters.
</para>
<para>
The <option>--round</option> and <option>--noopt</option>
options were obsoleted as these were only used with the old non-library crypto code
</para>
<para>
The <option>--random</option> device is only used for seeding the crypto library,
not for direct random to generate keys
</para>
</refsect1>
<refsect1 id='bugs'>
<title>BUGS</title>
<para>
<command>ecdsasigkey</command>'s run time is difficult
to predict, since <filename>/dev/random</filename> output can
be arbitrarily delayed if the system's entropy pool is low on
randomness, and the time taken by the search for primes is also somewhat
unpredictable. Specifically, embedded systems and most virtual machines are low on
entropy. In such a situation, consider generating the ECDSA key on another machine,
and copying <filename>ipsec.secrets</filename> and the <filename>@@IPSEC_NSSDIR@@</filename>
directory tree to the embedded platform. Note that NSS embeds the full path in the DB files, so
the path on proxy machine must be identical to the path on the destination machine.
</para>
</refsect1>
<refsect1 id='author'>
<title>AUTHOR</title>
<para>
<author><personname><firstname>Paul</firstname><surname>Wouters</surname></personname></author>
</para>
</refsect1>
</refentry>
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