summaryrefslogtreecommitdiffstats
path: root/man/passwd.1.xml
diff options
context:
space:
mode:
Diffstat (limited to 'man/passwd.1.xml')
-rw-r--r--man/passwd.1.xml515
1 files changed, 515 insertions, 0 deletions
diff --git a/man/passwd.1.xml b/man/passwd.1.xml
new file mode 100644
index 0000000..0e8ba32
--- /dev/null
+++ b/man/passwd.1.xml
@@ -0,0 +1,515 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ Copyright (c) 1989 - 1994, Julianne Frances Haugh
+ Copyright (c) 2007 - 2011, 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.
+-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
+ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
+<!ENTITY ENCRYPT_METHOD SYSTEM "login.defs.d/ENCRYPT_METHOD.xml">
+<!ENTITY MD5_CRYPT_ENAB SYSTEM "login.defs.d/MD5_CRYPT_ENAB.xml">
+<!ENTITY OBSCURE_CHECKS_ENAB SYSTEM "login.defs.d/OBSCURE_CHECKS_ENAB.xml">
+<!ENTITY PASS_ALWAYS_WARN SYSTEM "login.defs.d/PASS_ALWAYS_WARN.xml">
+<!ENTITY PASS_CHANGE_TRIES SYSTEM "login.defs.d/PASS_CHANGE_TRIES.xml">
+<!ENTITY PASS_MAX_LEN SYSTEM "login.defs.d/PASS_MAX_LEN.xml">
+<!ENTITY SHA_CRYPT_MIN_ROUNDS SYSTEM "login.defs.d/SHA_CRYPT_MIN_ROUNDS.xml">
+<!-- SHADOW-CONFIG-HERE -->
+]>
+<refentry id='passwd.1'>
+ <!-- $Id$ -->
+ <refentryinfo>
+ <author>
+ <firstname>Julianne Frances</firstname>
+ <surname>Haugh</surname>
+ <contrib>Creation, 1989</contrib>
+ </author>
+ <author>
+ <firstname>Thomas</firstname>
+ <surname>Kłoczko</surname>
+ <email>kloczek@pld.org.pl</email>
+ <contrib>shadow-utils maintainer, 2000 - 2007</contrib>
+ </author>
+ <author>
+ <firstname>Nicolas</firstname>
+ <surname>François</surname>
+ <email>nicolas.francois@centraliens.net</email>
+ <contrib>shadow-utils maintainer, 2007 - now</contrib>
+ </author>
+ </refentryinfo>
+ <refmeta>
+ <refentrytitle>passwd</refentrytitle>
+ <manvolnum>1</manvolnum>
+ <refmiscinfo class="sectdesc">User Commands</refmiscinfo>
+ <refmiscinfo class="source">shadow-utils</refmiscinfo>
+ <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
+ </refmeta>
+ <refnamediv id='name'>
+ <refname>passwd</refname>
+ <refpurpose>change user password</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv id='synopsis'>
+ <cmdsynopsis>
+ <command>passwd</command>
+ <arg choice='opt'>
+ <replaceable>options</replaceable>
+ </arg>
+ <arg choice='opt'>
+ <replaceable>LOGIN</replaceable>
+ </arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1 id='description'>
+ <title>DESCRIPTION</title>
+ <para>
+ The <command>passwd</command> command changes passwords for user accounts.
+ A normal user may only change the password for their own account, while
+ the superuser may change the password for any account.
+ <command>passwd</command> also changes the account or associated
+ password validity period.
+ </para>
+
+ <refsect2 id='password_changes'>
+ <title>Password Changes</title>
+ <para>
+ The user is first prompted for their old password, if one is
+ present. This password is then encrypted and compared against the
+ stored password. The user has only one chance to enter the correct
+ password. The superuser is permitted to bypass this step so that
+ forgotten passwords may be changed.
+ </para>
+
+ <para>
+ After the password has been entered, password aging information is
+ checked to see if the user is permitted to change the password at
+ this time. If not, <command>passwd</command> refuses to change the
+ password and exits.
+ </para>
+
+ <para>
+ The user is then prompted twice for a replacement password. The
+ second entry is compared against the first and both are required to
+ match in order for the password to be changed.
+ </para>
+
+ <para>
+ Then, the password is tested for complexity. As a general guideline,
+ passwords should consist of 6 to 8 characters including one or more
+ characters from each of the following sets:
+ </para>
+
+ <itemizedlist mark='bullet'>
+ <listitem>
+ <para>lower case alphabetics</para>
+ </listitem>
+ <listitem>
+ <para>digits 0 thru 9</para>
+ </listitem>
+ <listitem>
+ <para>punctuation marks</para>
+ </listitem>
+ </itemizedlist>
+
+ <para>
+ Care must be taken not to include the system default erase or kill
+ characters. <command>passwd</command> will reject any password which
+ is not suitably complex.
+ </para>
+
+ </refsect2>
+
+ <refsect2 id='hints_for_user_passwords'>
+ <title>Hints for user passwords</title>
+ <para>
+ The security of a password depends upon the strength of the
+ encryption algorithm and the size of the key space. The legacy
+ <emphasis>UNIX</emphasis> System encryption method is based on the
+ NBS DES algorithm. More recent methods are now recommended (see
+ <option>ENCRYPT_METHOD</option>). The size of the key space
+ depends upon the randomness of the password which is selected.
+ </para>
+
+ <para>
+ Compromises in password security normally result from careless
+ password selection or handling. For this reason, you should not
+ select a password which appears in a dictionary or which must be
+ written down. The password should also not be a proper name, your
+ license number, birth date, or street address. Any of these may be
+ used as guesses to violate system security.
+ </para>
+
+ <para>
+ You can find advice on how to choose a strong password on
+ http://en.wikipedia.org/wiki/Password_strength
+ </para>
+ </refsect2>
+ </refsect1>
+
+ <refsect1 id='options'>
+ <title>OPTIONS</title>
+ <para>
+ The options which apply to the <command>passwd</command> command are:
+ </para>
+ <variablelist remap='IP'>
+ <varlistentry>
+ <term>
+ <option>-a</option>, <option>--all</option>
+ </term>
+ <listitem>
+ <para>
+ This option can be used only with <option>-S</option> and causes show
+ status for all users.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-d</option>, <option>--delete</option>
+ </term>
+ <listitem>
+ <para>
+ Delete a user's password (make it empty). This is a quick way
+ to disable a password for an account. It will set the named
+ account passwordless.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-e</option>, <option>--expire</option>
+ </term>
+ <listitem>
+ <para>
+ Immediately expire an account's password. This in effect can
+ force a user to change their password at the user's next login.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>-h</option>, <option>--help</option></term>
+ <listitem>
+ <para>Display help message and exit.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-i</option>, <option>--inactive</option>&nbsp;<replaceable>INACTIVE</replaceable>
+ </term>
+ <listitem>
+ <para>
+ This option is used to disable an account after the password has
+ been expired for a number of days. After a user account has had
+ an expired password for <replaceable>INACTIVE</replaceable>
+ days, the user may no longer sign on to the account.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-k</option>, <option>--keep-tokens</option>
+ </term>
+ <listitem>
+ <para>
+ Indicate password change should be performed only for expired
+ authentication tokens (passwords). The user wishes to keep their
+ non-expired tokens as before.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-l</option>, <option>--lock</option>
+ </term>
+ <listitem>
+ <para>
+ Lock the password of the named account. This option disables a
+ password by changing it to a value which matches no possible
+ encrypted value (it adds a ´!´ at the beginning of the
+ password).
+ </para>
+ <para>
+ Note that this does not disable the account. The user may
+ still be able to login using another authentication token
+ (e.g. an SSH key). To disable the account, administrators
+ should use <command>usermod --expiredate 1</command> (this set
+ the account's expire date to Jan 2, 1970).
+ </para>
+ <para>
+ Users with a locked password are not allowed to change their
+ password.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-n</option>, <option>--mindays</option>&nbsp;<replaceable>MIN_DAYS</replaceable>
+ </term>
+ <listitem>
+ <para>
+ Set the minimum number of days between password changes to
+ <replaceable>MIN_DAYS</replaceable>. A value of zero for this field
+ indicates that the user may change their password at any time.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-q</option>, <option>--quiet</option>
+ </term>
+ <listitem>
+ <para>
+ Quiet mode.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-r</option>, <option>--repository</option>&nbsp;<replaceable>REPOSITORY</replaceable>
+ </term>
+ <listitem>
+ <para>
+ change password in <replaceable>REPOSITORY</replaceable> repository
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-R</option>, <option>--root</option>&nbsp;<replaceable>CHROOT_DIR</replaceable>
+ </term>
+ <listitem>
+ <para>
+ Apply changes in the <replaceable>CHROOT_DIR</replaceable>
+ directory and use the configuration files from the
+ <replaceable>CHROOT_DIR</replaceable> directory.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-S</option>, <option>--status</option>
+ </term>
+ <listitem>
+ <para>
+ Display account status information. The status information
+ consists of 7 fields. The first field is the user's login name.
+ The second field indicates if the user account has a locked
+ password (L),
+ has no password (NP), or has a usable password (P). The third
+ field gives the date of the last password change. The next four
+ fields are the minimum age, maximum age, warning period, and
+ inactivity period for the password. These ages are expressed in
+ days.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-u</option>, <option>--unlock</option>
+ </term>
+ <listitem>
+ <para>
+ Unlock the password of the named account. This option
+ re-enables a password by changing the password back to its
+ previous value (to the value before using the
+ <option>-l</option> option).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-w</option>, <option>--warndays</option>&nbsp;<replaceable>WARN_DAYS</replaceable>
+ </term>
+ <listitem>
+ <para>
+ Set the number of days of warning before a password change is
+ required. The <replaceable>WARN_DAYS</replaceable> option is
+ the number of days prior to the password expiring that a user
+ will be warned that their password is about to expire.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>
+ <option>-x</option>, <option>--maxdays</option>&nbsp;<replaceable>MAX_DAYS</replaceable>
+ </term>
+ <listitem>
+ <para>
+ Set the maximum number of days a password remains valid. After
+ <replaceable>MAX_DAYS</replaceable>, the password is required
+ to be changed.
+ </para>
+ <para>
+ Passing the number <emphasis remap='I'>-1</emphasis> as
+ <replaceable>MAX_DAYS</replaceable> will remove checking a
+ password's validity.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1 id='caveats'>
+ <title>CAVEATS</title>
+ <para>
+ Password complexity checking may
+ vary from site to site. The user is urged to select a password as
+ complex as he or she feels comfortable with.
+ </para>
+ <para>
+ Users may not be able to
+ change their password on a system if NIS is enabled and they are not
+ logged into the NIS server.
+ </para>
+ <para condition="pam">
+ <command>passwd</command> uses PAM to authenticate users and to
+ change their passwords.
+ </para>
+ </refsect1>
+
+ <refsect1 id='configuration' condition="no_pam">
+ <title>CONFIGURATION</title>
+ <para>
+ The following configuration variables in
+ <filename>/etc/login.defs</filename> change the behavior of this
+ tool:
+ </para>
+ <variablelist>
+ &ENCRYPT_METHOD;
+ &MD5_CRYPT_ENAB;
+ &OBSCURE_CHECKS_ENAB;
+ &PASS_ALWAYS_WARN;
+ &PASS_CHANGE_TRIES;
+ &PASS_MAX_LEN; <!-- documents also PASS_MIN_LEN -->
+ &SHA_CRYPT_MIN_ROUNDS;
+ </variablelist>
+ </refsect1>
+
+ <refsect1 id='files'>
+ <title>FILES</title>
+ <variablelist>
+ <varlistentry>
+ <term><filename>/etc/passwd</filename></term>
+ <listitem>
+ <para>User account information.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>/etc/shadow</filename></term>
+ <listitem>
+ <para>Secure user account information.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry condition="no_pam">
+ <term><filename>/etc/login.defs</filename></term>
+ <listitem>
+ <para>Shadow password suite configuration.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry condition="pam">
+ <term><filename>/etc/pam.d/passwd</filename></term>
+ <listitem>
+ <para>PAM configuration for <command>passwd</command>.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1 id='exit_values'>
+ <title>EXIT VALUES</title>
+ <para>
+ The <command>passwd</command> command exits with the following values:
+ <variablelist>
+ <varlistentry>
+ <term><replaceable>0</replaceable></term>
+ <listitem>
+ <para>success</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>1</replaceable></term>
+ <listitem>
+ <para>permission denied</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>2</replaceable></term>
+ <listitem>
+ <para>invalid combination of options</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>3</replaceable></term>
+ <listitem>
+ <para>unexpected failure, nothing done</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>4</replaceable></term>
+ <listitem>
+ <para>unexpected failure, <filename>passwd</filename> file missing</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>5</replaceable></term>
+ <listitem>
+ <para><filename>passwd</filename> file busy, try again</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><replaceable>6</replaceable></term>
+ <listitem>
+ <para>invalid argument to option</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1 id='see_also'>
+ <title>SEE ALSO</title>
+ <para>
+ <citerefentry>
+ <refentrytitle>chpasswd</refentrytitle><manvolnum>8</manvolnum>
+ </citerefentry>,
+ <citerefentry>
+ <refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum>
+ </citerefentry>,
+ <citerefentry>
+ <refentrytitle>shadow</refentrytitle><manvolnum>5</manvolnum>
+ </citerefentry>,
+ <phrase condition="no_pam">
+ <citerefentry>
+ <refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
+ </citerefentry>,
+ </phrase>
+ <citerefentry>
+ <refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
+ </citerefentry>.
+ </para>
+ </refsect1>
+</refentry>