<!--
   Copyright (c) 2007 - 2008, Nicolas François
   All rights reserved.
  
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:
   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
   3. The name of the copyright holders or contributors may not be used to
      endorse or promote products derived from this software without
      specific prior written permission.
  
   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
   HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-->
<varlistentry condition="sha_crypt">
  <term><option>SHA_CRYPT_MIN_ROUNDS</option> (number)</term>
  <term><option>SHA_CRYPT_MAX_ROUNDS</option> (number)</term>
  <listitem>
    <para>
      When <option>ENCRYPT_METHOD</option> is set to
      <replaceable>SHA256</replaceable> or
      <replaceable>SHA512</replaceable>, this defines the number of SHA
      rounds used by the encryption algorithm by default (when the number
      of rounds is not specified on the command line).
    </para>
    <para>
      With a lot of rounds, it is more difficult to brute forcing the
      password. But note also that more CPU resources will be needed to
      authenticate users.
    </para>
    <para>
      If not specified, the libc will choose the default number of rounds
      (5000).
    </para>
    <para>
      The values must be inside the 1000-999,999,999 range.
    </para>
    <para>
      If only one of the <option>SHA_CRYPT_MIN_ROUNDS</option> or
      <option>SHA_CRYPT_MAX_ROUNDS</option> values is set, then this value
      will be used.
    </para>
    <para>
      If <option>SHA_CRYPT_MIN_ROUNDS</option> &gt;
      <option>SHA_CRYPT_MAX_ROUNDS</option>, the highest value will be
      used.
    </para>
    <para condition="pam">
      Note: This only affect the generation of group passwords.
      The generation of user passwords is done by PAM and subject to the
      PAM configuration. It is recommended to set this variable
      consistently with the PAM configuration.
    </para>
  </listitem>
</varlistentry>
