1<!-- doc/src/sgml/auth-delay.sgml -->
2
3<sect1 id="auth-delay" xreflabel="auth_delay">
4 <title>auth_delay</title>
5
6 <indexterm zone="auth-delay">
7  <primary>auth_delay</primary>
8 </indexterm>
9
10 <para>
11  <filename>auth_delay</filename> causes the server to pause briefly before
12  reporting authentication failure, to make brute-force attacks on database
13  passwords more difficult.  Note that it does nothing to prevent
14  denial-of-service attacks, and may even exacerbate them, since processes
15  that are waiting before reporting authentication failure will still consume
16  connection slots.
17 </para>
18
19 <para>
20  In order to function, this module must be loaded via
21  <xref linkend="guc-shared-preload-libraries"/> in <filename>postgresql.conf</filename>.
22 </para>
23
24 <sect2>
25  <title>Configuration Parameters</title>
26
27  <variablelist>
28   <varlistentry>
29    <term>
30     <varname>auth_delay.milliseconds</varname> (<type>int</type>)
31     <indexterm>
32      <primary><varname>auth_delay.milliseconds</varname> configuration parameter</primary>
33     </indexterm>
34    </term>
35    <listitem>
36     <para>
37      The number of milliseconds to wait before reporting an authentication
38      failure.  The default is 0.
39     </para>
40    </listitem>
41   </varlistentry>
42  </variablelist>
43
44  <para>
45   These parameters must be set in <filename>postgresql.conf</filename>.
46   Typical usage might be:
47  </para>
48
49<programlisting>
50# postgresql.conf
51shared_preload_libraries = 'auth_delay'
52
53auth_delay.milliseconds = '500'
54</programlisting>
55 </sect2>
56
57 <sect2>
58  <title>Author</title>
59
60  <para>
61   KaiGai Kohei <email>kaigai@ak.jp.nec.com</email>
62  </para>
63 </sect2>
64
65</sect1>
66