Provided by: openafs-client_1.4.6.dfsg1-2_i386
klog - Authenticates with the Authentication Server
klog [-x] [-principal <user name>]
[-password <userâ€™s password>] [-cell <cell name>]
[-servers <explicit list of servers>+]
[-lifetime <ticket lifetime in hh[:mm[:ss]]>]
[-setpag] [-tmp] [-help]
klog [-x] [-pr <user name>] [-pa <userâ€™s password>]
[-c <cell name>] [-s <explicit list of servers>+]
[-pi] [-si] [-l <ticket lifetime in hh[:mm[:ss]]>]
[-se] [-t] [-h]
The klog command obtains an AFS token from the Authentication Server.
The Cache Manager on the local machine stores the token in a credential
structure in kernel memory and uses it when obtaining authenticated
access to the AFS filespace. This command does not affect the issuerâ€™s
identity (UNIX UID) in the local file system.
By default, the command interpreter obtains a token for the AFS user
name that matches the issuerâ€™s identity in the local file system. To
specify an alternate user, include the -principal argument. The user
named by the -principal argument does not have to appear in the local
password file (the /etc/passwd file or equivalent).
By default, the command interpreter obtains a token for the local cell,
as defined by the AFSCELL environment variable set in the command shell
or by the /etc/openafs/ThisCell file on the local machine. To specify
an alternate cell, include the -cell argument. The command interpreter
contacts an Authentication Server chosen at random from the cellâ€™s
entry in the local /etc/openafs/server/CellServDB file, unless the
-servers argument is used to name one or more database server machines.
A user can have tokens in multiple cells simultaneously, but only one
token per cell per connection to the client machine. If the userâ€™s
credential structure already contains a token for the requested cell,
the token resulting from this command replaces it.
Sites that employ Kerberos authentication instead of the AFS
Authentication Server should normally use the combination of kinit and
aklog instead of klog.
Sites using Kerberos v4 authentication (perhaps with the AFS
Authentication Server) must use the Kerberos version of this command,
klog.krb, on all client machines. It automatically places the issuerâ€™s
Kerberos tickets in the file named by the KRBTKFILE environment
variable, which the pagsh.krb command defines automatically as
/tmp/tktpX where X is the number of the userâ€™s PAG.
The lifetime of the token resulting from this command is the smallest
of the following.
Â· The lifetime specified by the issuer with the -lifetime argument.
If the issuer does not include this argument, the value defaults to
720 hours (30 days).
Â· The maximum ticket lifetime recorded for the afs entry in the
Authentication Database. The default is 100 hours.
Â· The maximum ticket lifetime recorded in the specified userâ€™s
Authentication Database entry. The default is 25 hours for user
entries created by an Authentication Server running AFS 3.1 or
Â· The maximum ticket lifetime recorded in the krbtgt.CELLNAME entry
in the Authentication Database; this entry corresponds to the
ticket-granting ticket used internally in generating the token. The
default is 720 hours (30 days).
The output from the kas examine command displays an Authentication
Database entryâ€™s maximum ticket lifetime as "Max ticket lifetime".
Administrators can display any entry, and users can display their own
If none of the defaults have been changed, the token lifetime is 25
hours for user accounts created by an Authentication Server running AFS
3.1 or higher. The maximum lifetime for any token is 720 hours (30
days), and the minimum is 5 minutes.
Between the minimum and maximum values, the Authentication Server uses
a defined set of values, according to the following rules. Requested
lifetimes between 5 minutes and 10 hours 40 minutes are granted at 5
minute intervals, rounding up. For example, if the issuer requests a
lifetime of 12 minutes, the tokenâ€™s actual lifetime is 15 minutes.
For token lifetimes greater than 10 hours 40 minutes, consult the
following table, which presents all the possible times in units of
hours:minutes:seconds. The number in parentheses is an approximation
of the corresponding time in days and hours (as indicated by the "d"
and "h" letters). For example, "282:22:17" means 282 hours, 22 minutes,
and 17 seconds, which translates to approximately 11 days and 18 hours
("11d 18h"). The Authentication Server rounds up a requested lifetime
to the next highest possible lifetime.
11:24:15 (0d 11h) 46:26:01 (1d 22h) 189:03:38 (7d 21h)
12:11:34 (0d 12h) 49:38:40 (2d 01h) 202:08:00 (8d 10h)
13:02:09 (0d 13h) 53:04:37 (2d 05h) 216:06:35 (9d 00h)
13:56:14 (0d 13h) 56:44:49 (2d 08h) 231:03:09 (9d 15h)
14:54:03 (0d 14h) 60:40:15 (2d 12h) 247:01:43 (10d 07h)
15:55:52 (0d 15h) 64:51:57 (2d 16h) 264:06:34 (11d 00h)
17:01:58 (0d 17h) 69:21:04 (2d 21h) 282:22:17 (11d 18h)
18:12:38 (0d 18h) 74:08:46 (3d 02h) 301:53:45 (12d 13h)
19:28:11 (0d 19h) 79:16:23 (3d 07h) 322:46:13 (13d 10h)
20:48:57 (0d 20h) 84:45:16 (3d 12h) 345:05:18 (14d 09h)
22:15:19 (0d 22h) 90:36:53 (3d 18h) 368:56:58 (15d 08h)
23:47:38 (0d 23h) 96:52:49 (4d 00h) 394:27:37 (16d 10h)
25:26:21 (1d 01h) 103:34:45 (4d 07h) 421:44:07 (17d 13h)
27:11:54 (1d 03h) 110:44:28 (4d 14h) 450:53:46 (18d 18h)
29:04:44 (1d 05h) 118:23:54 (4d 22h) 482:04:24 (20d 02h)
31:05:22 (1d 07h) 126:35:05 (5d 06h) 515:24:22 (21d 11h)
33:14:21 (1d 09h) 135:20:15 (5d 15h) 551:02:38 (22d 23h)
35:32:15 (1d 11h) 144:41:44 (6d 00h) 589:08:45 (24d 13h)
37:59:41 (1d 13h) 154:42:01 (6d 10h) 629:52:56 (26d 05h)
40:37:19 (1d 16h) 165:23:50 (6d 21h) 673:26:07 (28d 01h)
43:25:50 (1d 19h) 176:50:01 (7d 08h)
By default, this command does not create a new process authentication
group (PAG); see the description of the pagsh command to learn about
PAGs. If a cell does not use an AFS-modified login utility, users must
include -setpag option to this command, or issue the pagsh command
before this one, to have their tokens stored in a credential structure
that is identified by PAG rather than by local UID.
When a credential structure is identified by local UID, the potential
security exposure is that the local superuser "root" can use the UNIX
su command to assume any other identity and automatically inherit the
tokens associated with that UID. Identifying the credential structure
by PAG eliminates this exposure.
If the -password argument is used, the specified password cannot begin
with a hyphen, because it is interpreted as another option name. Use
of the -password argument is not recommended in any case.
By default, it is possible to issue this command on a properly
configured NFS client machine that is accessing AFS via the NFS/AFS
Translator, assuming that the NFS client machine is a supported system
type. However, if the translator machineâ€™s administrator has enabled
UID checking by including the -uidcheck on argument to the fs exportafs
command, the command fails with an error message similar to the
Warning: Remote pioctl to <translator_machine> has failed (err=8). . .
Unable to authenticate to AFS because a pioctl failed.
Enabling UID checking means that the credential structure in which
tokens are stored on the translator machine must be identified by a UID
that matches the local UID of the process that is placing the tokens in
the credential structure. After the klog command interpreter obtains
the token on the NFS client, it passes it to the remote executor daemon
on the translator machine, which makes the system call that stores the
token in a credential structure on the translator machine. The remote
executor generally runs as the local superuser "root", so in most cases
its local UID (normally zero) does not match the local UID of the user
who issued the klog command on the NFS client machine.
Issuing the klog command on an NFS client machine creates a security
exposure: the command interpreter passes the token across the network
to the remote executor daemon in clear text mode.
-x Appears only for backwards compatibility. Its former function is
now the default behavior of this command.
-principal <user name>
Specifies the user name to authenticate. If this argument is
omitted, the Authentication Server attempts to authenticate the
user logged into the local system.
-password <userâ€™s password>
Specifies the issuerâ€™s password (or that of the alternate user
identified by the -principal argument). Omit this argument to have
the command interpreter prompt for the password, in which case it
does not echo visibly in the command shell.
-cell <cell name>
Specifies the cell for which to obtain a token. The command is
directed to that cellâ€™s Authentication Servers. During a single
login session on a given machine, a user can be authenticated in
multiple cells simultaneously, but can have only one token at a
time for each of them (that is, can only authenticate under one
identity per cell per session on a machine). It is acceptable to
abbreviate the cell name to the shortest form that distinguishes it
from the other cells listed in the /etc/openafs/CellServDB file on
the client machine on which the command is issued.
If this argument is omitted, the command is executed in the local
cell, as defined
* First, by the value of the environment variable AFSCELL.
* Second, in the /etc/openafs/ThisCell file on the client machine
on which the command is issued.
-servers <explicit list of servers>+
Establishes a connection with the Authentication Server running on
each specified database server machine. The command interpreter
then chooses one of these at random to execute the command. It is
best to provide fully-qualified hostnames, but abbreviated forms
are possibly acceptable depending on the state of the cellâ€™s name
server at the time the command is issued. This option is useful for
testing specific servers if problems are encountered.
If this argument is omitted, the command interpreter establishes a
connection with each machine listed for the indicated cell in the
local copy of the /etc/openafs/CellServDB file, and then chooses
one of them at random for command execution.
Suppresses all output to the standard output stream, including
prompts and error messages. The klog command interpreter expects to
receive the password from the standard input stream. Do not use
this argument; it is designed for use by application programs
rather than human users.
Suppresses some of the trace messages that the klog command
produces on the standard output stream by default. It still reports
on major problems encountered.
-lifetime <ticket lifetime
Requests a specific lifetime for the token. Provide a number of
hours and optionally minutes and seconds in the format
hh[:mm[:ss]]. The value is used in calculating the token lifetime
as described in DESCRIPTION.
Creates a process authentication group (PAG) prior to requesting
authentication. The token is associated with the newly created PAG.
Creates a Kerberos-style ticket file in the /tmp directory of the
local machine. The file is called tkt.AFS_UID where AFS_UID is the
AFS UID of the issuer.
Prints the online help for this command. All other valid options
The following message indicates that the limit on consecutive
authentication failures has been exceeded. An administrator can use the
kas unlock command to unlock the account, or the issuer can wait until
the lockout time for the account has passed. (The time is set with the
-locktime argument to the kas setfields command and displayed in the
output from the kas examine command).
Unable to authenticate to AFS because ID is locked - see your system admin
If the -tmp flag is included, the following message confirms that a
Kerberos-style ticket file was created:
Wrote ticket file to /tmp
Most often, this command is issued without arguments. The appropriate
password is for the person currently logged into the local system. The
ticketâ€™s lifetime is calculated as described in DESCRIPTION (if no
defaults have been changed, it is 25 hours for a user whose
Authentication Database entry was created in AFS 3.1 or later).
The following example authenticates the user as admin in the ABC
Corporationâ€™s test cell:
% klog -principal admin -cell test.abc.com
In the following, the issuer requests a ticket lifetime of 104 hours 30
minutes (4 days 8 hours 30 minutes). Presuming that this lifetime is
allowed by the maximum ticket lifetimes and other factors described in
DESCRIPTION, the tokenâ€™s lifetime is 110:44:28, which is the next
largest possible value.
% klog -lifetime 104:30
fs_exportafs(1), kas_examine(8), kas_setfields(8), kas_unlock(8),
kaserver(8), pagsh(1), tokens(1)
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
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and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.