mirror of
https://github.com/Zeckmathederg/glfs.git
synced 2025-01-26 08:42:12 +08:00
618b9a7723
git-svn-id: svn://svn.linuxfromscratch.org/BLFS/trunk/BOOK@7195 af4574ff-66df-0310-9fd7-8a98e5e911e0
410 lines
15 KiB
XML
410 lines
15 KiB
XML
<?xml version="1.0" encoding="ISO-8859-1"?>
|
|
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
|
|
<!ENTITY % general-entities SYSTEM "../../general.ent">
|
|
%general-entities;
|
|
|
|
<!ENTITY openssh-download-http "http://sunsite.ualberta.ca/pub/OpenBSD/OpenSSH/portable/openssh-&openssh-version;.tar.gz">
|
|
<!ENTITY openssh-download-ftp "ftp://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-&openssh-version;.tar.gz">
|
|
<!ENTITY openssh-md5sum "50a800fd2c6def9e9a53068837e87b91">
|
|
<!ENTITY openssh-size "968 KB">
|
|
<!ENTITY openssh-buildsize "16.2 MB">
|
|
<!ENTITY openssh-time "0.5 SBU (additional 1.2 SBU to run the test suite)">
|
|
]>
|
|
|
|
<sect1 id="openssh" xreflabel="OpenSSH-&openssh-version;">
|
|
<?dbhtml filename="openssh.html"?>
|
|
|
|
<sect1info>
|
|
<othername>$LastChangedBy$</othername>
|
|
<date>$Date$</date>
|
|
</sect1info>
|
|
|
|
<title>OpenSSH-&openssh-version;</title>
|
|
|
|
<indexterm zone="openssh">
|
|
<primary sortas="a-OpenSSH">OpenSSH</primary>
|
|
</indexterm>
|
|
|
|
<sect2 role="package">
|
|
<title>Introduction to OpenSSH</title>
|
|
|
|
<para>The <application>OpenSSH</application> package contains
|
|
<command>ssh</command> clients and the <command>sshd</command> daemon.
|
|
This is useful for encrypting authentication and subsequent traffic
|
|
over a network.</para>
|
|
|
|
<bridgehead renderas="sect3">Package Information</bridgehead>
|
|
<itemizedlist spacing="compact">
|
|
<listitem>
|
|
<para>Download (HTTP): <ulink url="&openssh-download-http;"/></para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Download (FTP): <ulink url="&openssh-download-ftp;"/></para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Download MD5 sum: &openssh-md5sum;</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Download size: &openssh-size;</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Estimated disk space required: &openssh-buildsize;</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>Estimated build time: &openssh-time;</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
<bridgehead renderas="sect3">OpenSSH Dependencies</bridgehead>
|
|
|
|
<bridgehead renderas="sect4">Required</bridgehead>
|
|
<para role="required"><xref linkend="openssl"/></para>
|
|
|
|
<bridgehead renderas="sect4">Optional</bridgehead>
|
|
<para role="optional"><xref linkend="linux-pam"/>,
|
|
<xref linkend="tcpwrappers"/>,
|
|
<xref linkend="x-window-system"/>,
|
|
<xref linkend="mitkrb"/> or <xref linkend="heimdal"/>,
|
|
<xref linkend="net-tools"/>,
|
|
<xref linkend="sysstat"/>,
|
|
<ulink url="http://www.opensc-project.org/">OpenSC</ulink>, and
|
|
<ulink
|
|
url="http://www.citi.umich.edu/projects/smartcard/sectok.html">libsectok</ulink></para>
|
|
|
|
<para condition="html" role="usernotes">User Notes:
|
|
<ulink url='&blfs-wiki;/OpenSSH'/></para>
|
|
|
|
</sect2>
|
|
|
|
<sect2 role="installation">
|
|
<title>Installation of OpenSSH</title>
|
|
|
|
<para><application>OpenSSH</application> runs as two processes when
|
|
connecting to other computers. The first process is a privileged process
|
|
and controls the issuance of privileges as necessary. The second process
|
|
communicates with the network. Additional installation steps are necessary
|
|
to set up the proper environment, which are performed by issuing the
|
|
following commands as the <systemitem class="username">root</systemitem>
|
|
user:</para>
|
|
|
|
<screen role="root"><userinput>install -v -m700 -d /var/lib/sshd &&
|
|
chown -v root:sys /var/lib/sshd &&
|
|
groupadd -g 50 sshd &&
|
|
useradd -c 'sshd PrivSep' -d /var/lib/sshd -g sshd \
|
|
-s /bin/false -u 50 sshd</userinput></screen>
|
|
|
|
<para><application>OpenSSH</application> is very sensitive to changes in
|
|
the linked <application>OpenSSL</application> libraries. If you recompile
|
|
<application>OpenSSL</application>, <application>OpenSSH</application> may
|
|
fail to startup. An alternative is to link against the static
|
|
<application>OpenSSL</application> library. To link against the static
|
|
library, execute the following command:</para>
|
|
|
|
<screen><userinput>sed -i 's@-lcrypto@/usr/lib/libcrypto.a -ldl@' configure</userinput></screen>
|
|
|
|
<para>Install <application>OpenSSH</application> by running
|
|
the following commands:</para>
|
|
|
|
<screen><userinput>sed -i 's@ -ldes@@' configure &&
|
|
./configure --prefix=/usr --sysconfdir=/etc/ssh --datadir=/usr/share/sshd \
|
|
--libexecdir=/usr/lib/openssh --with-md5-passwords \
|
|
--with-privsep-path=/var/lib/sshd \
|
|
--with-xauth=/usr/bin/xauth &&
|
|
make</userinput></screen>
|
|
|
|
<para>If you linked <application>tcp_wrappers</application> into the
|
|
build using the <option>--with-tcp-wrappers</option> parameter, ensure
|
|
you add 127.0.0.1 to the sshd line in <filename>/etc/hosts.allow</filename>
|
|
if you have a restrictive <filename>/etc/hosts.deny</filename> file, or the
|
|
test suite will fail. Additionally, the testsuite requires an installed
|
|
copy of <command>scp</command> to complete the mulitplexing tests. To
|
|
run the test suite, issue the following commnds as the
|
|
<systemitem class="username">root</systemitem> user:</para>
|
|
|
|
<screen role="root"><userinput>if test -f /usr/bin/scp
|
|
then
|
|
mv /usr/bin/scp /usr/bin/scp-bak
|
|
fi &&
|
|
cp scp /usr/bin/scp &&
|
|
make tests 2>&1 | tee check.log
|
|
grep "FATAL" check.log</userinput></screen>
|
|
|
|
<para>If the above command produces no 'FATAL' errors, then proceed
|
|
with the installation, again as the
|
|
<systemitem class="username">root</systemitem> user:</para>
|
|
|
|
<screen role="root"><userinput>rm /usr/bin/scp &&
|
|
if test -f /usr/bin/scp-bak
|
|
then
|
|
rm /usr/bin/scp-bak
|
|
fi &&
|
|
make install &&
|
|
install -v -m755 -d /usr/share/doc/openssh-&openssh-version; &&
|
|
install -v -m644 INSTALL LICENCE OVERVIEW README* WARNING.RNG \
|
|
/usr/share/doc/openssh-&openssh-version;</userinput></screen>
|
|
|
|
</sect2>
|
|
|
|
<sect2 role="commands">
|
|
<title>Command Explanations</title>
|
|
|
|
<para><command>sed -i 's@ -ldes@@' configure</command>:
|
|
This command fixes a build crash if you used the
|
|
<option>--with-kerberos5</option> parameter and you built the
|
|
<application>Heimdal</application> package in accordance with the BLFS
|
|
instructions. The command is harmless in all other instances.</para>
|
|
|
|
<para><parameter>--sysconfdir=/etc/ssh</parameter>: This prevents
|
|
the configuration files from being installed in
|
|
<filename class="directory">/usr/etc</filename>.</para>
|
|
|
|
<para><parameter>--datadir=/usr/share/sshd</parameter>: This switch
|
|
puts the Ssh.bin file (used for SmartCard authentication) in
|
|
<filename class="directory">/usr/share/sshd</filename>.</para>
|
|
|
|
<!-- WOW, this description is really old, IIRC it was obsolete shortly
|
|
before I was an editor, as the hint became a part of both books.
|
|
I'll leave it in for now JIC - Delete Later
|
|
<para><parameter>- -with-md5-passwords</parameter>: This is required
|
|
if you made the changes recommended by the shadowpasswd_plus
|
|
LFS hint on your SSH server when you installed the Shadow Password
|
|
Suite or if you access a SSH server that authenticates by
|
|
user passwords encrypted with md5.</para>
|
|
-->
|
|
|
|
<para><parameter>--with-md5-passwords</parameter>: This is required
|
|
with the default configuration of Shadow password suite in LFS.</para>
|
|
|
|
<para><parameter>--libexecdir=/usr/lib/openssh</parameter>: This parameter
|
|
changes the installation path of some programs to
|
|
<filename class="directory">/usr/lib/openssh</filename> instead of
|
|
<filename class="directory">/usr/libexec</filename>.</para>
|
|
|
|
<para><parameter>--with-pam</parameter>: This parameter enables
|
|
<application>Linux-PAM</application> support in the build.</para>
|
|
|
|
<para><parameter>--with-xauth=/usr/bin/xauth</parameter>: Set the
|
|
default location for the <command>xauth</command> binary for X
|
|
authentication. Change the location if <command>xauth</command> will
|
|
be installed to a different path. This can also be controlled from
|
|
<filename>sshd_config</filename> with the XAuthLocation keyword.
|
|
You can omit this switch if <application>Xorg</application> is already
|
|
installed.
|
|
</para>
|
|
|
|
</sect2>
|
|
|
|
<sect2 role="configuration">
|
|
<title>Configuring OpenSSH</title>
|
|
|
|
<sect3 id="openssh-config">
|
|
<title>Config Files</title>
|
|
|
|
<para><filename>~/.ssh/*</filename>,
|
|
<filename>/etc/ssh/ssh_config</filename>, and
|
|
<filename>/etc/ssh/sshd_config</filename></para>
|
|
|
|
<indexterm zone="openssh openssh-config">
|
|
<primary sortas="e-AA.ssh">~/.ssh/*</primary>
|
|
</indexterm>
|
|
|
|
<indexterm zone="openssh openssh-config">
|
|
<primary sortas="e-etc-ssh-ssh_config">/etc/ssh/ssh_config</primary>
|
|
</indexterm>
|
|
|
|
<indexterm zone="openssh openssh-config">
|
|
<primary sortas="e-etc-ssh-sshd_config">/etc/ssh/sshd_config</primary>
|
|
</indexterm>
|
|
|
|
<para>There are no required changes to any of these files. However,
|
|
you may wish to view the <filename class='directory'>/etc/ssh/</filename>
|
|
files and make any changes appropriate for the security of your system.
|
|
One recommended change is that you disable
|
|
<systemitem class='username'>root</systemitem> login via
|
|
<command>ssh</command>. Execute the following command as the
|
|
<systemitem class='username'>root</systemitem> user to disable
|
|
<systemitem class='username'>root</systemitem> login via
|
|
<command>ssh</command>:</para>
|
|
|
|
<screen role="root"><userinput>echo "PermitRootLogin no" >> /etc/ssh/sshd_config</userinput></screen>
|
|
|
|
<para>If you added <application>LinuxPAM</application> support, then you
|
|
will need to add a configuration file for
|
|
<application>sshd</application>. Issue the following commands as the
|
|
<systemitem class='username'>root</systemitem> user:</para>
|
|
|
|
<screen role="root"><userinput>sed 's@d/login@d/sshd@g' /etc/pam.d/login > /etc/pam.d/sshd &&
|
|
chmod 644 /etc/pam.d/sshd</userinput></screen>
|
|
|
|
<para>Additional configuration information can be found in the man
|
|
pages for <command>sshd</command>, <command>ssh</command> and
|
|
<command>ssh-agent</command>.</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="openssh-init">
|
|
<title>Boot Script</title>
|
|
|
|
<para>To start the SSH server at system boot, install the
|
|
<filename>/etc/rc.d/init.d/sshd</filename> init script included
|
|
in the <xref linkend="bootscripts"/> package.</para>
|
|
|
|
<indexterm zone="openssh openssh-init">
|
|
<primary sortas="f-sshd">sshd</primary>
|
|
</indexterm>
|
|
|
|
<screen role="root"><userinput>make install-sshd</userinput></screen>
|
|
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 role="content">
|
|
<title>Contents</title>
|
|
|
|
<segmentedlist>
|
|
<segtitle>Installed Programs</segtitle>
|
|
<segtitle>Installed Libraries</segtitle>
|
|
<segtitle>Installed Directories</segtitle>
|
|
|
|
<seglistitem>
|
|
<seg>scp, sftp, sftp-server, slogin, ssh, sshd, ssh-add, ssh-agent,
|
|
ssh-keygen, ssh-keyscan, and ssh-keysign</seg>
|
|
<seg>None</seg>
|
|
<seg>/etc/ssh, /var/lib/sshd and
|
|
/usr/share/doc/openssh-&openssh-version;</seg>
|
|
</seglistitem>
|
|
</segmentedlist>
|
|
|
|
<variablelist>
|
|
<bridgehead renderas="sect3">Short Descriptions</bridgehead>
|
|
<?dbfo list-presentation="list"?>
|
|
<?dbhtml list-presentation="table"?>
|
|
|
|
<varlistentry id="scp">
|
|
<term><command>scp</command></term>
|
|
<listitem>
|
|
<para>is a file copy program that acts like <command>rcp</command>
|
|
except it uses an encrypted protocol.</para>
|
|
<indexterm zone="openssh scp">
|
|
<primary sortas="b-scp">scp</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="sftp">
|
|
<term><command>sftp</command></term>
|
|
<listitem>
|
|
<para>is an FTP-like program that works over
|
|
SSH1 and SSH2 protocols.</para>
|
|
<indexterm zone="openssh sftp">
|
|
<primary sortas="b-sftp">sftp</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="sftp-server">
|
|
<term><command>sftp-server</command></term>
|
|
<listitem>
|
|
<para>is an SFTP server subsystem. This program is not normally
|
|
called directly by the user.</para>
|
|
<indexterm zone="openssh sftp-server">
|
|
<primary sortas="b-sftp-server">sftp-server</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="slogin">
|
|
<term><command>slogin</command></term>
|
|
<listitem>
|
|
<para>is a symlink to <command>ssh</command>.</para>
|
|
<indexterm zone="openssh slogin">
|
|
<primary sortas="g-slogin">slogin</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh">
|
|
<term><command>ssh</command></term>
|
|
<listitem>
|
|
<para>is an <command>rlogin</command>/<command>rsh</command>-like
|
|
client program except it uses an encrypted protocol.</para>
|
|
<indexterm zone="openssh ssh">
|
|
<primary sortas="b-ssh">ssh</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="sshd">
|
|
<term><command>sshd</command></term>
|
|
<listitem>
|
|
<para>is a daemon that listens for <command>ssh</command> login
|
|
requests.</para>
|
|
<indexterm zone="openssh sshd">
|
|
<primary sortas="b-sshd">sshd</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh-add">
|
|
<term><command>ssh-add</command></term>
|
|
<listitem>
|
|
<para>is a tool which adds keys to the
|
|
<command>ssh-agent</command>.</para>
|
|
<indexterm zone="openssh ssh-add">
|
|
<primary sortas="b-ssh-add">ssh-add</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh-agent">
|
|
<term><command>ssh-agent</command></term>
|
|
<listitem>
|
|
<para>is an authentication agent that can store private keys.</para>
|
|
<indexterm zone="openssh ssh-agent">
|
|
<primary sortas="b-ssh-agent">ssh-agent</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh-keygen">
|
|
<term><command>ssh-keygen</command></term>
|
|
<listitem>
|
|
<para>is a key generation tool.</para>
|
|
<indexterm zone="openssh ssh-keygen">
|
|
<primary sortas="b-ssh-keygen">ssh-keygen</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh-keyscan">
|
|
<term><command>ssh-keyscan</command></term>
|
|
<listitem>
|
|
<para>is a utility for gathering public host keys from a
|
|
number of hosts.</para>
|
|
<indexterm zone="openssh ssh-keyscan">
|
|
<primary sortas="b-ssh-keyscan">ssh-keyscan</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry id="ssh-keysign">
|
|
<term><command>ssh-keysign</command></term>
|
|
<listitem>
|
|
<para>is used by <command>ssh</command> to access the local host
|
|
keys and generate the digital signature required during hostbased
|
|
authentication with SSH protocol version 2. This program is not normally
|
|
called directly by the user.</para>
|
|
<indexterm zone="openssh ssh-keysign">
|
|
<primary sortas="b-ssh-keysign">ssh-keysign</primary>
|
|
</indexterm>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
|
|
|
</sect2>
|
|
|
|
</sect1>
|