MINI MINI MANI MO
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>passwordcheck</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Additional Supplied Modules"
HREF="contrib.html"><LINK
REL="PREVIOUS"
TITLE="pageinspect"
HREF="pageinspect.html"><LINK
REL="NEXT"
TITLE="pg_buffercache"
HREF="pgbuffercache.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="pageinspect"
HREF="pageinspect.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="contrib.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Appendix F. Additional Supplied Modules</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="pg_buffercache"
HREF="pgbuffercache.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="PASSWORDCHECK"
>F.23. passwordcheck</A
></H1
><P
> The <TT
CLASS="FILENAME"
>passwordcheck</TT
> module checks users' passwords
whenever they are set with
<A
HREF="sql-createrole.html"
>CREATE ROLE</A
> or
<A
HREF="sql-alterrole.html"
>ALTER ROLE</A
>.
If a password is considered too weak, it will be rejected and
the command will terminate with an error.
</P
><P
> To enable this module, add <TT
CLASS="LITERAL"
>'$libdir/passwordcheck'</TT
>
to <A
HREF="runtime-config-resource.html#GUC-SHARED-PRELOAD-LIBRARIES"
>shared_preload_libraries</A
> in
<TT
CLASS="FILENAME"
>postgresql.conf</TT
>, then restart the server.
</P
><P
> You can adapt this module to your needs by changing the source code.
For example, you can use
<A
HREF="http://sourceforge.net/projects/cracklib/"
TARGET="_top"
>CrackLib</A
>
to check passwords — this only requires uncommenting
two lines in the <TT
CLASS="FILENAME"
>Makefile</TT
> and rebuilding the
module. (We cannot include <SPAN
CLASS="PRODUCTNAME"
>CrackLib</SPAN
>
by default for license reasons.)
Without <SPAN
CLASS="PRODUCTNAME"
>CrackLib</SPAN
>, the module enforces a few
simple rules for password strength, which you can modify or extend
as you see fit.
</P
><DIV
CLASS="CAUTION"
><P
></P
><TABLE
CLASS="CAUTION"
BORDER="1"
WIDTH="100%"
><TR
><TD
ALIGN="CENTER"
><B
>Caution</B
></TD
></TR
><TR
><TD
ALIGN="LEFT"
><P
> To prevent unencrypted passwords from being sent across the network,
written to the server log or otherwise stolen by a database administrator,
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> allows the user to supply
pre-encrypted passwords. Many client programs make use of this
functionality and encrypt the password before sending it to the server.
</P
><P
> This limits the usefulness of the <TT
CLASS="FILENAME"
>passwordcheck</TT
>
module, because in that case it can only try to guess the password.
For this reason, <TT
CLASS="FILENAME"
>passwordcheck</TT
> is not
recommended if your security requirements are high.
It is more secure to use an external authentication method such as Kerberos
(see <A
HREF="client-authentication.html"
>Chapter 19</A
>) than to rely on
passwords within the database.
</P
><P
> Alternatively, you could modify <TT
CLASS="FILENAME"
>passwordcheck</TT
>
to reject pre-encrypted passwords, but forcing users to set their
passwords in clear text carries its own security risks.
</P
></TD
></TR
></TABLE
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="pageinspect.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="pgbuffercache.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>pageinspect</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="contrib.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>pg_buffercache</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
OHA YOOOO