klog.afs - Online in the Cloud

PROGRAM:

NAME

klog, klog.krb - Authenticates with the Authentication Server

SYNOPSIS

klog [-x] [-principal <user name>]
[-password <user's password>] [-cell <cell name>]
[-servers <explicit list of servers>+]
[-pipe] [-silent]
[-lifetime <ticket lifetime in hh[:mm[:ss]]>]
[-setpag] [-tmp] [-help]

klog [-x] [-pr <user name>] [-pa <user's password>]
[-c <cell name>] [-s <explicit list of servers>+]
[-pi] [-si] [-l <ticket lifetime in hh[:mm[:ss]]>]
[-se] [-t] [-h]

klog.krb [-x] [-principal <user name>]
[-password <user's password>] [-cell <cell name>]
[-servers <explicit list of servers>+]
[-pipe] [-silent]
[-lifetime <ticket lifetime in hh[:mm[:ss]]>]
[-setpag] [-tmp] [-help]

DESCRIPTION

The klog and klog.krb commands are obsolete and should not be used. Instead, use kinit
followed by aklog or klog.krb5. See aklog(1) and klog.krb5(1) for more information.

The klog command obtains an AFS token from the obsolete Authentication Server or a
Kerberos KDC that speaks the same protocol, such as fakeka or a Heimdal Kerberos KDC. 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 issuer's identity (UNIX UID) in the local file system.

The klog.krb command obtains an AFS token from the obsolete Authentication Server or a
Kerberos v4 KDC and also places the issuer's Kerberos v4 tickets in the file named by the
KRBTKFILE environment variable. The Kerberos v4 ticket may used by Kerberos v4 aware
programs. The pagsh.krb command defines the KRBTKFILE environment variable as /tmp/tktpX
where X is the number of the user's PAG.

By default, the command interpreter obtains a token for the AFS user name that matches the
issuer'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 cell'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 user's credential structure already contains a
token for the requested cell, the token resulting from this command replaces it.

The lifetime of the token resulting from this command is the smallest of the following.

· 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).

· The maximum ticket lifetime recorded for the afs entry in the Authentication Database.
The default is 100 hours.

· The maximum ticket lifetime recorded in the specified user's Authentication Database
entry. The default is 25 hours for user entries created by an Authentication Server
running AFS 3.1 or later.

· 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 entry's
maximum ticket lifetime as "Max ticket lifetime". Administrators can display any entry,
and users can display their own entries.

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 token'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)

CAUTIONS

klog speaks a protocol specific to the obsolete Authentication Server and is provided
primarily to support cells that have not yet migrated to a Kerberos version 5 KDC. It is
still useful at cells not running the Authentication Server if the associated Kerberos
realm supports Authentication Server queries (such as a Heimdal KDC or fakeka), but using
klog.krb5 or kinit plus aklog instead of this command is recommended.

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 machine'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 following:

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.

OPTIONS

-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 <user's password>
Specifies the issuer'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 cell'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 cell'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.

-pipe
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.

-silent
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.

-setpag
Creates a process authentication group (PAG) prior to requesting authentication. The
token is associated with the newly created PAG.

-tmp
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.

-help
Prints the online help for this command. All other valid options are ignored.

OUTPUT

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

EXAMPLES

Most often, this command is issued without arguments. The appropriate password is for the
person currently logged into the local system. The ticket'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).

% klog
Password:

The following example authenticates the user as admin in the ABC Corporation's test cell:

% klog -principal admin -cell test.abc.com
Password:

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 token's lifetime is 110:44:28, which is
the next largest possible value.

% klog -lifetime 104:30
Password:

PRIVILEGE REQUIRED

None

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