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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML
><HEAD
><TITLE
>Using AFS</TITLE
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>AFS User Guide: Version 3.6</TH
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><DIV
CLASS="chapter"
><H1
><A
NAME="HDRWQ20"
></A
>Chapter 2. Using AFS</H1
><P
>This chapter explains how to perform four basic AFS tasks: logging in and authenticating with AFS, ending an AFS session,
accessing the AFS filespace, and changing your password.</P
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="HDRWQ21"
>Logging in and Authenticating with AFS</A
></H1
><P
>To access the AFS filespace as an authenticated user, you must both log into an AFS client machine's local (UNIX) file
system and authenticate with AFS. When you log in, you establish your local system identity. When you authenticate, you prove
your identity to AFS and obtain a token, which your Cache Manager uses to prove your authenticated status to the AFS server
processes it contacts on your behalf. Users who are not authenticated (who do not have a token) have limited access to AFS
directories and files.</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ22"
>Logging In</A
></H2
><P
>On machines that use an AFS-modified login utility, you log in and authenticate in one step. On machines that do not use
an AFS-modified login utility, you log in and authenticate in separate steps. To determine which type of login utility your
machine uses, you can check for AFS tokens after logging in, or ask your system administrator, who can also tell you about any
differences between your login procedure and the two methods described here.</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_33"
>To Log In Using an AFS-modified Login Utility</A
></H2
><P
>Provide your username at the <SAMP
CLASS="computeroutput"
>login:</SAMP
> prompt that appears when you establish a new
connection to a machine. Then provide your password at the <SAMP
CLASS="computeroutput"
>Password:</SAMP
> prompt as shown in the
following example. (Your password does not echo visibly on the screen.)</P
><PRE
CLASS="programlisting"
>&#13; login: <VAR
CLASS="replaceable"
>username</VAR
>
Password: <VAR
CLASS="replaceable"
>password</VAR
>
</PRE
><P
>If you are not sure which type of login utility is running on your machine, it is best to issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command to check if you are authenticated; for instructions, see <A
HREF="c569.html#HDRWQ30"
>To
Display Your Tokens</A
>. If you do not have tokens, issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command as described in
<A
HREF="c569.html#HDRWQ29"
>To Authenticate with AFS</A
>.</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ23"
>To Log In Using a Two-Step Login Procedure</A
></H2
><P
>If your machine does not use an AFS-modified login utility, you must perform a two-step procedure:
<OL
TYPE="1"
><LI
><P
>Log in to your client machine's local file system by providing a user name and password at the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>login</B
></SPAN
> program's prompts.</P
></LI
><LI
><P
>Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command to authenticate with AFS. Include the command's <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-setpag</B
></SPAN
> argument to associate your token with a special identification number called a
<SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>PAG</I
></SPAN
> (for <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>process authentication group</I
></SPAN
>). For a description of PAGs, see <A
HREF="c569.html#HDRWQ25"
>Protecting Your Tokens with a PAG</A
>. <PRE
CLASS="programlisting"
>&#13;
% <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog -setpag</B
></SPAN
>
Password: <VAR
CLASS="replaceable"
>your_AFS_password</VAR
>
</PRE
></P
></LI
></OL
>
</P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>If your machine uses a two-step login procedure, you can choose to use different passwords for logging in and
authenticating. It is simplest to use the same one for both, though. Talk with your system administrator.</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ24"
>Authenticating with AFS</A
></H2
><P
>To work most effectively in the AFS filespace, you must authenticate with AFS. When you do, your Cache Manager is given
a token as proof of your authenticated status. It uses your token when requesting services from AFS servers, which accept the
token as proof of your authenticated status. If you do not have a token, AFS servers consider you to be the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>anonymous</B
></SPAN
> user and your access to AFS filespace is limited: you have only the ACL permissions granted
to the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>system:anyuser</B
></SPAN
> group. </P
><P
>You can obtain new tokens (reauthenticate) at any time, even after using an AFS-modified login utility, which logs you
in and authenticates you in one step. Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command as described in <A
HREF="c569.html#HDRWQ29"
>To Authenticate with AFS</A
>.</P
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="HDRWQ25"
>Protecting Your Tokens with a PAG</A
></H3
><P
>To make your access to AFS as secure as possible, it is best to associate your tokens with a unique identification
number called a <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>PAG</I
></SPAN
> (for <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>process authentication group</I
></SPAN
>).
AFS-modified login utilities automatically create a PAG and associate the new
token with it. To create a PAG when you use the two-step login procedure, include the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
>
command's <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-setpag</B
></SPAN
> flag. If you do not use this flag, your tokens are associated with your
UNIX UID number instead. This type of association has two potential drawbacks:
<UL
><LI
><P
>Anyone who can assume your local UNIX identity can use your tokens. The local superuser <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>root</B
></SPAN
> can always use the UNIX <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>su</B
></SPAN
> command to assume your UNIX UID,
even without knowing your password.</P
></LI
><LI
><P
>In some environments, certain programs cannot use your tokens even when it is appropriate for them to do so. For
example, printing commands such as <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>lp</B
></SPAN
> or <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>lpr</B
></SPAN
> possibly
cannot access the files you want to print, because they cannot use your tokens.</P
></LI
></UL
>
</P
></DIV
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="HDRWQ26"
>Obtaining Tokens For Foreign Cells</A
></H3
><P
>A token is valid only in one cell (the cell whose AFS authentication service issued it). The AFS server processes in
any other cell consider you to be the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>anonymous</B
></SPAN
> user unless you have an account in the cell
and authenticate with its AFS authentication service.</P
><P
>To obtain tokens in a foreign cell, use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
> argument to the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command. You can have tokens for your home cell and one or more foreign cells at the same
time.</P
></DIV
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="HDRWQ27"
>The One-Token-Per-Cell Rule</A
></H3
><P
>You can have only one token per cell for each PAG you have obtained on a client machine. If you already have a token
for a particular cell and issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command, the new token overwrites the existing
one. Getting a new token is useful if your current token is almost expired but you want to continue accessing AFS files. For
a discussion of token expiration, see <A
HREF="c569.html#HDRWQ28"
>Token Lifetime</A
>.</P
><P
>To obtain a second token for the same cell, you must either login on a different machine or establish another separate
connection to the machine where you already have a token (by using the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>telnet</B
></SPAN
> utility, for
example). You get a new PAG for each separate machine or connection, and can use the associated tokens only while working on
that machine or connection.</P
></DIV
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="Header_39"
>Obtaining Tokens as Another User</A
></H3
><P
>You can authenticate as another username if you know the associated password. (It is, of course, unethical to use
someone else's tokens without permission.) If you use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command to authenticate as
another AFS username, you retain your own local (UNIX) identity, but the AFS server processes recognize you as the other
user. The new token replaces any token you already have for the relevant cell (for the reason described in <A
HREF="c569.html#HDRWQ27"
>The One-Token-Per-Cell Rule</A
>).</P
></DIV
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="HDRWQ28"
>Token Lifetime</A
></H3
><P
>Tokens have a limited lifetime. To determine when your tokens expire, issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command as described in <A
HREF="c569.html#HDRWQ30"
>To Display Your Tokens</A
>. If you are ever
unable to access AFS in a way that you normally can, issuing the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command tells you
whether an expired token is a possible reason.</P
><P
>Your cell's administrators set the default lifetime of your token. The AFS authentication service never grants a token
lifetime longer than the default, but you can request a token with a shorter lifetime. See the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> reference page in the <SPAN
CLASS="emphasis"
><I
CLASS="emphasis"
>IBM AFS Administration Reference</I
></SPAN
> to learn how to use
its <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-lifetime</B
></SPAN
> argument for this purpose.</P
></DIV
><DIV
CLASS="sect3"
><H3
CLASS="sect3"
><A
NAME="Header_41"
>Authenticating for DFS Access</A
></H3
><P
>If your machine is configured to access a DCE cell's DFS filespace by means of the AFS/DFS Migration Toolkit, you can
use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dlog</B
></SPAN
> command to authenticate with DCE. The <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dlog</B
></SPAN
>
command has no effect on your ability to access AFS filespace.</P
><P
>If your system administrator has converted your AFS account to a DCE account and you are not sure of your DCE
password, use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dpass</B
></SPAN
> command to display it. You must be authenticated as the AFS user
whose AFS account was converted to a DCE account, and be able to provide the correct AFS password. Like the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dlog</B
></SPAN
> command, the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dpass</B
></SPAN
> command has no functionality with respect to
AFS.</P
><P
>For more information on using the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dlog</B
></SPAN
> and <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>dpass</B
></SPAN
>
commands, see your system administrator.</P
></DIV
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ29"
>To Authenticate with AFS</A
></H2
><P
>If your machine is not using an AFS-modified login utility, you must authenticate after login by issuing the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command. You can also issue this command at any time to obtain a token with a later expiration
date than your current token.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> [<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-setpag</B
></SPAN
>] [<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
> &#60;<VAR
CLASS="replaceable"
>cell name</VAR
>&#62;]
Password: <VAR
CLASS="replaceable"
>your_AFS_password</VAR
>
</PRE
><P
>where
<DIV
CLASS="variablelist"
><DL
><DT
><SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-setpag</B
></SPAN
></DT
><DD
><P
>Associates the resulting tokens with a PAG (see <A
HREF="c569.html#HDRWQ25"
>Protecting Your Tokens with a PAG</A
>).
Include this flag the first time you obtain a token for a particular cell during a login session or connection. Do not
include it when refreshing the token for a cell during the same session.</P
></DD
><DT
><SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
></DT
><DD
><P
>Names the cell for which to obtain the token. You must have an account in the cell.</P
></DD
></DL
></DIV
>
</P
><P
>Your password does not echo visibly appear on the screen. When the command shell prompt returns, you are an
authenticated AFS user. You can use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command to verify that you are authenticated,
as described in the following section.</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ30"
>To Display Your Tokens</A
></H2
><P
>Use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command to display your tokens.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
</PRE
><P
>The following output indicates that you have no tokens:</P
><PRE
CLASS="programlisting"
>&#13; Tokens held by the Cache Manager:
--End of list--
</PRE
><P
>If you have one or more tokens, the output looks something like the following example, in which the tokens for AFS UID
1022 in the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>abc.com</B
></SPAN
> cell expire on August 3 at 2:35 p.m. The tokens for AFS UID 9554 in the
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>stateu.edu</B
></SPAN
> cell expire on August 4 at 1:02 a.m.</P
><PRE
CLASS="programlisting"
>&#13; Tokens held by the Cache Manager:
User's (AFS ID 1022) tokens for afs@abc.com [Expires Aug 3 14:35]
User's (AFS ID 9554) tokens for afs@stateu.edu [Expires Aug 4 1:02]
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_44"
>Example: Authenticating in the Local Cell</A
></H2
><P
>Suppose that user <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>terry</B
></SPAN
> cannot save a file. He uses the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command and finds that his tokens have expired. He reauthenticates in his local cell under his
current identity by issuing the following command:</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
>
Password: <VAR
CLASS="replaceable"
>terry's_password</VAR
>
</PRE
><P
>The he issues the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command to make sure he is authenticated.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
User's (AFS ID 4562) tokens for afs@abc.com [Expires Jun 22 14:35]
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_45"
>Example: Authenticating as a Another User</A
></H2
><P
>Now <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>terry</B
></SPAN
> authenticates in his local cell as another user, <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>pat</B
></SPAN
>. The new token replaces <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>terry</B
></SPAN
>'s existing token, because the Cache
Manager can store only one token per cell per login session on a machine.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog pat</B
></SPAN
>
Password: <VAR
CLASS="replaceable"
>pat's_password</VAR
>
% <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
User's (AFS ID 4278) tokens for afs@abc.com [Expires Jun 23 9:46]
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_46"
>Example: Authenticating in a Foreign Cell</A
></H2
><P
>Now <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>terry</B
></SPAN
> authenticates in the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>stateu.edu</B
></SPAN
> cell where
his account is called <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>ts09</B
></SPAN
>.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog ts09 -cell stateu.edu</B
></SPAN
>
Password: <VAR
CLASS="replaceable"
>ts09's_password</VAR
>
% <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
User's (AFS ID 4562) tokens for afs@abc.com [Expires Jun 22 14:35]
User's (AFS ID 8346) tokens for afs@stateu.edu [Expires Jun 23 1:02]
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ31"
>Limits on Failed Authentication Attempts</A
></H2
><P
>Your system administrator can choose to limit the number of times that you fail to provide the correct password when
authenticating with AFS (using either an AFS-modified login utility or the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command). If
you exceed the limit, the AFS authentication service refuses further authentication attempts for a period of time set by your
system administrator. The purpose of this limit is to prevent unauthorized users from breaking into your account by trying a
series of passwords.</P
><P
>To determine if your user account is subject to this limit, ask your system administrator or issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
> command as described in <A
HREF="c569.html#HDRWQ32"
>To Display Your Failed Authentication Limit
and Lockout Time</A
>.</P
><P
>The following message indicates that you have exceeded the limit on failed authentication attempts.</P
><PRE
CLASS="programlisting"
>&#13; Unable to authenticate to AFS because ID is locked - see your system admin
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ32"
>To Display Your Failed Authentication Limit and Lockout Time</A
></H2
><P
>Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
> command to determine if there is a limit on the number of
unsuccessful authentication attempts for your user account and any associated lockout time. You can examine only your own
account. The fourth line of the output reports the maximum number of times you can provide an incorrect password before being
locked out of your account. The <SAMP
CLASS="computeroutput"
>lock time</SAMP
> field on the next line reports how long the AFS
authentication service refuses authentication attempts after the limit is exceeded.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
> <VAR
CLASS="replaceable"
>your_username</VAR
>
Password for <VAR
CLASS="replaceable"
>your_username</VAR
>: <VAR
CLASS="replaceable"
>your_AFS_password</VAR
>
</PRE
><P
>The following example displays the output for the user <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>pat</B
></SPAN
>, who is allowed nine failed
authentication attempts. The lockout time is 25.5 minutes.</P
><PRE
CLASS="programlisting"
>&#13; User data for pat
key (15) cksum is 3414844392, last cpw: Thu Oct 21 16:05:44 1999
password will expire: Fri Nov 26 20:44:36 1999
9 consecutive unsuccessful authentications are permitted.
The lock time for this user is 25.5 minutes.
User is not locked.
entry never expires. Max ticket lifetime 100.00 hours.
last mod on Wed Aug 18 08:22:29 1999 by admin
permit password reuse
</PRE
></DIV
></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="HDRWQ33"
>Exiting an AFS Session</A
></H1
><P
>Because logging in and authenticating with AFS are distinct operations, you must both logout and unauthenticate (issue the
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog</B
></SPAN
> command to discard your tokens) when exiting an AFS session. Simply logging out does not
necessarily destroy your tokens.</P
><P
>You can use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog</B
></SPAN
> command any time you want to unauthenticate, not just when logging
out. For instance, it is a good practice to unauthenticate before leaving your machine unattended, to prevent other users from
using your tokens during your absence. When you return to your machine, issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command
to reauthenticate, as described in <A
HREF="c569.html#HDRWQ29"
>To Authenticate with AFS</A
>.</P
><P
>Do not issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog</B
></SPAN
> command when you are running jobs that take a long time to
complete, even if you are logging out. Such processes must have a token during the entire time they need authenticated access to
AFS.</P
><P
>If you have tokens from multiple cells and want to discard only some of them, include the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog</B
></SPAN
> command's <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
> argument.</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_50"
>To Discard Tokens</A
></H2
><P
>Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog</B
></SPAN
> command to discard your tokens:</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog -cell</B
></SPAN
> &#60;<VAR
CLASS="replaceable"
>cell name</VAR
>&#62;<SUP
>+</SUP
>
</PRE
><P
>Omit the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
> argument to discard all of your tokens, or use it to name each cell for
which to discard tokens. It is best to provide the full name of each cell (such as <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>stateu.edu</B
></SPAN
>
or <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>abc.com</B
></SPAN
>).</P
><P
>You can issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
> command to verify that your tokens were destroyed, as in the
following example.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_51"
>Example: Unauthenticating from a Specific Cell</A
></H2
><P
>In the following example, a user has tokens in both the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>accounting</B
></SPAN
> and <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>marketing</B
></SPAN
> cells at her company. She discards the token for the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>acctg.abc.com</B
></SPAN
> cell but keeps the token for the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>mktg.abc.com</B
></SPAN
>
cell.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
User's (AFS ID 35) tokens for afs@acctg.abc.com [Expires Nov 10 22:30]
User's (AFS ID 674) tokens for afs@mktg.abc.com [Expires Nov 10 18:44]
--End of list--
% <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>unlog -cell acctg.abc.com</B
></SPAN
>
% <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>tokens</B
></SPAN
>
Tokens held by the Cache Manager:
User's (AFS ID 674) tokens for afs@mktg.abc.com [Expires Nov 10 18:44]
--End of list--
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_52"
>To Log Out</A
></H2
><P
>After you have unauthenticated, log out by issuing the command appropriate for your machine type, which is possibly one
of the following.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>logout</B
></SPAN
>
</PRE
><P
>or</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>exit</B
></SPAN
>
</PRE
><P
>or</P
><PRE
CLASS="programlisting"
>&#13; % &#60;<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>Ctrl-d</B
></SPAN
>&#62;
</PRE
></DIV
></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="HDRWQ34"
>Accessing the AFS Filespace</A
></H1
><P
>While you are logged in and authenticated, you can access files in AFS just as you do in the UNIX file system. The only
difference is that you can access potentially many more files. Just as in the UNIX file system, you can only access those files
for which you have permission. AFS uses access control lists (ACLs) to control access, as described in <A
HREF="c1444.html"
>Protecting Your Directories and Files</A
>.</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_54"
>AFS Pathnames</A
></H2
><P
>AFS pathnames look very similar to UNIX file system names. The main difference is that every AFS pathname begins with
the AFS root directory, which is called <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>/afs</B
></SPAN
> by convention. Having <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>/afs</B
></SPAN
> at the top of every AFS cell's filespace links together their filespaces into a global filespace.
</P
><P
><SPAN
CLASS="bold"
><B
CLASS="emphasis"
>Note for Windows users:</B
></SPAN
> Windows uses a backslash (<28><SPAN
CLASS="bold"
><B
CLASS="emphasis"
>\</B
></SPAN
><EFBFBD>) rather than a forward slash (<28><SPAN
CLASS="bold"
><B
CLASS="emphasis"
>/</B
></SPAN
><EFBFBD>) to separate the
elements in a pathname. Otherwise, your access to AFS filespace is much the same as for users working on UNIX machines.</P
><P
>The second element in AFS pathnames is generally a cell's name. For example, the ABC Corporation cell is called
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>abc.com</B
></SPAN
> and the pathname of every file in its filespace begins with the string <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>/afs/abc.com</B
></SPAN
>. Some cells also create a directory at the second level with a shortened name (such as
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>abc</B
></SPAN
> for <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>abc.com</B
></SPAN
> or <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>stateu</B
></SPAN
>
for <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>stateu.edu</B
></SPAN
>), to reduce the amount of typing necessary. Your system administrator can tell
you if your cell's filespace includes shortened names like this. The rest of the pathname depends on how the cell's
administrators organized its filespace.</P
><P
>To access directories and files in AFS you must both specify the correct pathname and have the required permissions on
the ACL that protects the directory and the files in it.</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_55"
>Example: Displaying the Contents of Another User's Directory</A
></H2
><P
>The user <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>terry</B
></SPAN
> wants to look for a file belonging to another user, <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>pat</B
></SPAN
>. He issues the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>ls</B
></SPAN
> command on the appropriate pathname.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>ls /afs/abc.com/usr/pat/public</B
></SPAN
>
doc/ directions/
guide/ jokes/
library/
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ35"
>Accessing Foreign Cells</A
></H2
><P
>You can access files not only in your own cell, but in any AFS cell that you can reach via the network, regardless of
geographical location. There are two additional requirements:
<UL
><LI
><P
>Your Cache Manager's list of foreign cells must include the cell you want to access. Only the local superuser
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>root</B
></SPAN
> can edit the list of cells, but anyone can display it. See <A
HREF="c1095.html#HDRWQ42"
>Determining Access to Foreign Cells</A
>.</P
></LI
><LI
><P
>The ACL on the directory that houses the file, and on every parent directory in the pathname, must grant you the
necessary permissions. The simplest way for the directory's owner to extend permission to foreign users is to put an entry
for the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>system:anyuser</B
></SPAN
> group on the ACL.</P
><P
>The alternative is for the foreign cell's administrator to create an account for you, essentially making you a local
user in the cell. The directory's owner creates an ACL entry for you as for any other local user. To authenticate in the
foreign cell, issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>klog</B
></SPAN
> command with the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>-cell</B
></SPAN
>
argument.</P
></LI
></UL
>
</P
><P
>For further discussion of directory and file protection, see <A
HREF="c1444.html"
>Protecting Your Directories and
Files</A
>.</P
></DIV
></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="HDRWQ36"
>Changing Your Password</A
></H1
><P
>In cells that use an AFS-modified login utility, the password is the same for both logging in and authenticating with AFS.
In this case, you use a single command, <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kpasswd</B
></SPAN
>, to change the password.</P
><P
>If your machine does not use an AFS-modified login utility, there are separate passwords for logging into the local file
system and authenticating with AFS. (The two passwords can be the same or different, at your discretion.) In this case, use the
<SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kpasswd</B
></SPAN
> command to change your AFS password and the UNIX <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>passwd</B
></SPAN
> command to change your UNIX password.</P
><P
>Your system administrator can improve cell security by configuring several features that guide your choice of password.
Keep them in mind when you issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kpasswd</B
></SPAN
> command:
<UL
><LI
><P
>Limiting the amount of time your password is valid. This improves your cell's security by limiting the amount of time
an unauthorized user has to try to guess your password. Your system administrator needs to tell you when your password is
due to expire so that you can change it in time. The administrator can configure the AFS-modified login utility to report
this information automatically each time you log in. You can also use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
>
command to display the password expiration date, as instructed in <A
HREF="c569.html#HDRWQ37"
>To Display Password Expiration
Date and Reuse Policy</A
>.</P
><P
>You can change your password prior to the expiration date, but your system administrator can choose to set a minimum
time between password changes. The following message indicates that the minimum time has not yet passed.</P
><PRE
CLASS="programlisting"
>&#13; kpasswd: password was not changed because you changed it too
recently; see your system administrator
</PRE
></LI
><LI
><P
>Enforcing password quality standards, such as a minimum length or inclusion of nonalphabetic characters. The
administrator needs to tell you about such requirements so that you do not waste time picking unacceptable passwords.</P
></LI
><LI
><P
>Rejecting a password that is too similar to the last 20 passwords you used. You can use the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas
examine</B
></SPAN
> command to check whether this policy applies to you, as instructed in <A
HREF="c569.html#HDRWQ37"
>To Display
Password Expiration Date and Reuse Policy</A
>. The following message indicates that the password you have chosen is too
similar to a previous password. <PRE
CLASS="programlisting"
>&#13; kpasswd: Password was not changed because it seems like a reused password
</PRE
></P
></LI
></UL
>
</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="HDRWQ37"
>To Display Password Expiration Date and Reuse Policy</A
></H2
><P
>Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
> command to display your password expiration date and reuse
policy. You can examine only your own account. The third line of the output reports your password's expiration date. The last
line reports the password reuse policy that applies to you.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kas examine</B
></SPAN
> <VAR
CLASS="replaceable"
>your_username</VAR
>
Password for <VAR
CLASS="replaceable"
>your_username</VAR
>: <VAR
CLASS="replaceable"
>your_AFS_password</VAR
>
</PRE
><P
>The following example displays the output for the user <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>pat</B
></SPAN
>.</P
><PRE
CLASS="programlisting"
>&#13; User data for pat
key (15) cksum is 3414844392, last cpw: Thu Oct 21 16:05:44 1999
password will expire: Fri Nov 26 20:44:36 1999
9 consecutive unsuccessful authentications are permitted.
The lock time for this user is 25.5 minutes.
User is not locked.
entry never expires. Max ticket lifetime 100.00 hours.
last mod on Wed Aug 18 08:22:29 1999 by admin
don't permit password reuse
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_59"
>To Change Your AFS Password</A
></H2
><P
>Issue the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kpasswd</B
></SPAN
> command, which prompts you to provide your old and new passwords and
to confirm the new password. The passwords do not echo visibly on the screen.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>kpasswd</B
></SPAN
>
Old password: <VAR
CLASS="replaceable"
>current_password</VAR
>
New password (RETURN to abort): <VAR
CLASS="replaceable"
>new_password</VAR
>
Retype new password: <VAR
CLASS="replaceable"
>new_password</VAR
>
</PRE
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="Header_60"
>To Change Your UNIX Password</A
></H2
><P
> Issue the UNIX <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>passwd</B
></SPAN
> command, which prompts you to provide your old and new passwords and to confirm the new
password. The passwords do not echo visibly on the screen. On many machines, the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>passwd</B
></SPAN
>
resides in the <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>/bin</B
></SPAN
> directory, and you possibly need to type the complete pathname.</P
><PRE
CLASS="programlisting"
>&#13; % <SPAN
CLASS="bold"
><B
CLASS="emphasis"
>passwd</B
></SPAN
>
Changing password for <VAR
CLASS="replaceable"
>username</VAR
>.
Old password: <VAR
CLASS="replaceable"
>current_password</VAR
>
New password: <VAR
CLASS="replaceable"
>new_password</VAR
>
Retype new passwd: <VAR
CLASS="replaceable"
>new_password</VAR
>
</PRE
></DIV
></DIV
></DIV
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CLASS="NAVFOOTER"
><HR
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CELLSPACING="0"
><TR
><TD
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VALIGN="top"
><A
HREF="c113.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
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VALIGN="top"
><A
HREF="book1.html"
ACCESSKEY="H"
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><TD
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