Sophie: maildrop-1.7.0-17mdv2010.0 i586

maildrop-1.7.0-17mdv2010.0.i586.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML
><HEAD
><link rel='stylesheet' type='text/css' href='manpage.css'>
  <!-- $Id: userdbpw.sgml,v 1.1 2001/11/24 20:49:56 mrsam Exp $ -->
  <!-- Copyright 1998 - 2001 Double Precision, Inc.  See COPYING for -->
  <!-- distribution information. -->
<meta name="MSSmartTagsPreventParsing" content="TRUE">
<link rel="icon" href="icon.gif" type="image/gif" />
<TITLE
>userdbpw</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><H1
><A
NAME="USERDBPW"
></A
>userdbpw</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN10"
></A
><H2
>Name</H2
>userdbpw&nbsp;--&nbsp;create an encrypted password</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN13"
></A
><H2
>Synopsis</H2
><P
><B
CLASS="COMMAND"
>userdbpw</B
> [-md5 | -hmac-md5 | -hmac-sha1]  | <B
CLASS="COMMAND"
>userdb</B
> {<VAR
CLASS="REPLACEABLE"
>name</VAR
>}  set  {<VAR
CLASS="REPLACEABLE"
>field</VAR
>}</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN27"
></A
><H2
>DESCRIPTION</H2
><P
><B
CLASS="COMMAND"
>userdbpw</B
> enables secure entry of encrypted
passwords into <TT
CLASS="FILENAME"
>/etc/maildrop/userdb</TT
>.</P
><P
><B
CLASS="COMMAND"
>userdbpw</B
> reads a single line of text on
standard input, encrypts it, and prints the encrypted result to standard
output.</P
><P
>If standard input is attached to a terminal device,
<B
CLASS="COMMAND"
>userdbpw</B
> explicitly issues a "Password: " prompt on
standard error, and turns off echo while the password is entered.</P
><P
>The <VAR
CLASS="OPTION"
>-md5</VAR
> option is available on systems that use
MD5-hashed passwords (such as systems that use the current version of the
PAM library for authenticating, with MD5 passwords enabled).
This option creates an MD5 password hash, instead of using the
traditional <TT
CLASS="FUNCTION"
>crypt()</TT
> function.</P
><P
><VAR
CLASS="OPTION"
>-hmac-md5</VAR
> and <VAR
CLASS="OPTION"
>-hmac-sha1</VAR
> options
are available only if the userdb library is installed by an application
that uses a challenge/response authentication mechanism.
<VAR
CLASS="OPTION"
>-hmac-md5</VAR
> creates an intermediate HMAC context using the
MD5 hash function. <VAR
CLASS="OPTION"
>-hmac-sha1</VAR
> uses the SHA1 hash function
instead. Whether either HMAC function is actually available depends on the
actual application that installs the <VAR
CLASS="OPTION"
>userdb</VAR
> library.</P
><P
>Note that even though the result of HMAC hashing looks like an encrypted
password, it's really not.  HMAC-based challenge/response authentication
mechanisms require the cleartext password to be available as cleartext.
Computing an intermediate HMAC context does scramble the cleartext password,
however if its compromised, it WILL be possible for an attacker to succesfully
authenticate.  Therefore, applications that use challenge/response
authentication will store intermediate HMAC contexts in the "pw" fields in the
userdb database, which will be compiled into the
<TT
CLASS="FILENAME"
>userdbshadow.dat</TT
>
database, which has group and world permissions turned off. The
userdb library also requires that the cleartext userdb source for the
<TT
CLASS="FILENAME"
>userdb.dat</TT
> and
<TT
CLASS="FILENAME"
>userdbshadow.dat</TT
> databases is also stored with the
group and world permissions turned off.</P
><P
><B
CLASS="COMMAND"
>userdbpw</B
> is usually used together in a pipe with
<B
CLASS="COMMAND"
>userdb</B
>, which reads from standard input. For example:

<A
NAME="AEN52"
></A
><BLOCKQUOTE
CLASS="BLOCKQUOTE"
><DIV
CLASS="INFORMALEXAMPLE"
><P
></P
><A
NAME="AEN53"
></A
><P
CLASS="LITERALLAYOUT"
><B
CLASS="COMMAND"
>userdbpw -md5 | userdb users/john set systempw</B
></P
><P
></P
></DIV
></BLOCKQUOTE
></P
><P
>or:

<A
NAME="AEN57"
></A
><BLOCKQUOTE
CLASS="BLOCKQUOTE"
><DIV
CLASS="INFORMALEXAMPLE"
><P
></P
><A
NAME="AEN58"
></A
><P
CLASS="LITERALLAYOUT"
><B
CLASS="COMMAND"
>userdbpw -hmac-md5 | userdb users/john set hmac-md5pw</B
></P
><P
></P
></DIV
></BLOCKQUOTE
></P
><P
>These commands set the <VAR
CLASS="OPTION"
>systempw</VAR
> field in the record for
the user <VAR
CLASS="OPTION"
>john</VAR
> in <TT
CLASS="FILENAME"
>/etc/maildrop/userdb/users</TT
> file, and the
<VAR
CLASS="OPTION"
>hmac-md5pw</VAR
> field. Don't forget to run
<B
CLASS="COMMAND"
>makeuserdb</B
> for the change to take effect.</P
><P
>The following command does the same thing:
<A
NAME="AEN68"
></A
><BLOCKQUOTE
CLASS="BLOCKQUOTE"
><DIV
CLASS="INFORMALEXAMPLE"
><P
></P
><A
NAME="AEN69"
></A
><P
CLASS="LITERALLAYOUT"
><B
CLASS="COMMAND"
>userdb users/john set systempw=<VAR
CLASS="OPTION"
>SECRETPASSWORD</VAR
></B
></P
><P
></P
></DIV
></BLOCKQUOTE
></P
><P
>However, this command passes the secret password as an argument to the
<B
CLASS="COMMAND"
>userdb</B
> command, which can be viewed by anyone who happens
to run
<SPAN
CLASS="CITEREFENTRY"
><SPAN
CLASS="REFENTRYTITLE"
>ps</SPAN
>(1)</SPAN
>
at the same time. Using <B
CLASS="COMMAND"
>userdbpw</B
> allows the secret password
to be specified in a way that cannot be easily viewed by
<SPAN
CLASS="CITEREFENTRY"
><SPAN
CLASS="REFENTRYTITLE"
>ps</SPAN
>(1)</SPAN
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN82"
></A
><H2
>SEE ALSO</H2
><P
><A
HREF="userdb.html"
TARGET="_top"
><SPAN
CLASS="CITEREFENTRY"
><SPAN
CLASS="REFENTRYTITLE"
>userdb</SPAN
>(8)</SPAN
></A
>,
 
<A
HREF="makeuserdb.html"
TARGET="_top"
><SPAN
CLASS="CITEREFENTRY"
><SPAN
CLASS="REFENTRYTITLE"
>makeuserdb</SPAN
>(8)</SPAN
></A
></P
></DIV
></BODY
></HTML
>