source: postlfs/security/libpwquality.xml

<?xml version="1.0" encoding="UTF-8"?>
<!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 libpwquality-download-http "https://github.com/libpwquality/libpwquality/releases/download/libpwquality-&libpwquality-version;/libpwquality-&libpwquality-version;.tar.bz2">
  <!ENTITY libpwquality-download-ftp  " ">
  <!ENTITY libpwquality-md5sum        "6b70e355269aef0b9ddb2b9d17936f21">
  <!ENTITY libpwquality-size          "424 KB">
  <!ENTITY libpwquality-buildsize     "5.4 MB">
  <!ENTITY libpwquality-time          "0.1 SBU">
]>

<sect1 id="libpwquality" xreflabel="libpwquality-&libpwquality-version;">
  <?dbhtml filename="libpwquality.html"?>


  <title>libpwquality-&libpwquality-version;</title>

  <indexterm zone="libpwquality">
    <primary sortas="a-libpwquality">libpwquality</primary>
  </indexterm>

  <sect2 role="package">
    <title>Introduction to libpwquality</title>

    <para>
      The <application>libpwquality</application> package provides common
      functions for password quality checking and also scoring them based on
      their apparent randomness. The library also provides a function for
      generating random passwords with good pronounceability.
    </para>

    &lfs122_checked;

    <bridgehead renderas="sect3">Package Information</bridgehead>
    <itemizedlist spacing="compact">
      <listitem>
        <para>
          Download (HTTP): <ulink url="&libpwquality-download-http;"/>
        </para>
      </listitem>
      <listitem>
        <para>
          Download (FTP): <ulink url="&libpwquality-download-ftp;"/>
        </para>
      </listitem>
      <listitem>
        <para>
          Download MD5 sum: &libpwquality-md5sum;
        </para>
      </listitem>
      <listitem>
        <para>
          Download size: &libpwquality-size;
        </para>
      </listitem>
      <listitem>
        <para>
          Estimated disk space required: &libpwquality-buildsize;
        </para>
      </listitem>
      <listitem>
        <para>
          Estimated build time: &libpwquality-time;
        </para>
      </listitem>
    </itemizedlist>

    <bridgehead renderas="sect3">libpwquality Dependencies</bridgehead>

    <bridgehead renderas="sect4">Required</bridgehead>
    <para role="required">
      <xref linkend="cracklib"/>
    </para>

    <bridgehead renderas="sect4">Recommended</bridgehead>
    <para role="recommended">
      <xref linkend="linux-pam"/>
    </para>
  </sect2>

  <sect2 role="installation">
    <title>Installation of libpwquality</title>

    <para>
      Install <application>libpwquality</application> by running the following
      commands:
    </para>

<screen><userinput>./configure --prefix=/usr                      \
            --disable-static                   \
            --with-securedir=/usr/lib/security \
            --disable-python-bindings          &amp;&amp;
make &amp;&amp;
&build-wheel-cmd; $PWD/python</userinput></screen>

    <para>
      This package does not come with a test suite.
    </para>

    <para>
      Now, as the <systemitem class="username">root</systemitem> user:
    </para>

<screen role="root"><userinput>make install &amp;&amp;
&install-wheel; pwquality</userinput></screen>

  </sect2>

  <sect2 role="commands">
    <title>Command Explanations</title>

    <para>
      <parameter>--disable-python-bindings</parameter>: This parameter
      disables building Python bindings with the deprecated
      <command>python3 setup.py build</command> command.  The explicit
      instruction to build the Python 3 binding with the
      <command>pip3 wheel</command> command is provided.
    </para>

  </sect2>

  <sect2 role="configuration">
    <title>Configuring libpwquality</title>

    <para>
      <application>libpwquality</application> is intended to be a
      functional replacement for the now-obsolete
      <filename>pam_cracklib.so</filename> PAM module. To configure the system
      to use the <filename>pam_pwquality</filename> module, execute the
      following commands as the
      <systemitem class="username">root</systemitem> user:
    </para>

<screen role="root"><userinput>mv /etc/pam.d/system-password{,.orig} &amp;&amp;
cat &gt; /etc/pam.d/system-password &lt;&lt; "EOF"
<literal># Begin /etc/pam.d/system-password

# check new passwords for strength (man pam_pwquality)
password  required    pam_pwquality.so   authtok_type=UNIX retry=1 difok=1 \
                                         minlen=8 dcredit=0 ucredit=0 \
                                         lcredit=0 ocredit=0 minclass=1 \
                                         maxrepeat=0 maxsequence=0 \
                                         maxclassrepeat=0 gecoscheck=0 \
                                         dictcheck=1 usercheck=1 \
                                         enforcing=1 badwords="" \
                                         dictpath=/usr/lib/cracklib/pw_dict

# use yescrypt hash for encryption, use shadow, and try to use any
# previously defined authentication token (chosen password) set by any
# prior module.
password  required    pam_unix.so        yescrypt shadow try_first_pass

# End /etc/pam.d/system-password</literal>
EOF
</userinput></screen>

  </sect2>

  <sect2 role="content">
    <title>Contents</title>

    <segmentedlist>
      <segtitle>Installed Programs</segtitle>
      <segtitle>Installed Libraries</segtitle>
      <segtitle>Installed Directories</segtitle>

      <seglistitem>
        <seg>
          pwscore and pwmake
        </seg>
        <seg>
          pam_pwquality.so and libpwquality.so
        </seg>
        <seg>
          /usr/lib/python3.11/site-packages/pwquality-&libpwquality-version;.dist-info
          <!-- /etc/security was installed by Linux-PAM -->
        </seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="pwmake">
        <term><command>pwmake</command></term>
        <listitem>
          <para>
            is a simple configurable tool for generating random
            and relatively easily pronounceable passwords
          </para>
          <indexterm zone="libpwquality pwmake">
            <primary sortas="b-pwmake">pwmake</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="pwscore">
        <term><command>pwscore</command></term>
        <listitem>
          <para>
            is a simple tool for checking quality of a password
          </para>
          <indexterm zone="libpwquality pwscore">
            <primary sortas="b-pwscore">pwscore</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libpwquality-lib">
        <term><filename class="libraryfile">libpwquality.so</filename></term>
        <listitem>
          <para>
            contains API functions for checking the password quality
          </para>
          <indexterm zone="libpwquality libpwquality-lib">
            <primary sortas="c-libpwquality">libpwquality.so</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="pam_pwquality">
        <term><filename class="libraryfile">pam_pwquality.so</filename></term>
        <listitem>
          <para>
            is a <application>Linux PAM</application> module used to perform
            password quality checking
          </para>
          <indexterm zone="libpwquality pam_pwquality">
            <primary sortas="c-pam_pwquality">pam_pwquality.so</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>