Provided by: openafs-krb5_1.4.12+dfsg-3_i386 bug

NAME

       klog.krb5 - Authenticates to Kerberos and obtains a token

SYNOPSIS

       klog.krb5 [-x] [-principal <user name>]
           [-password <user’s password>] [-cell <cell name>]
           [-k <realm>] [-pipe] [-silent]
           [-lifetime <ticket lifetime in hh[:mm[:ss]]>]
           [-setpag] [-tmp] [-noprdb] [-unwrap] [-help]

       klog.krb5 [-x] [-pr <user name>]
           [-pa <user’s password>]
           [-c <cell name>]
           [-k <realm>] [-pi] [-si]
           [-l <ticket lifetime in hh[:mm[:ss]]>]
           [-se] [-t] [-n] [-u] [-h]

DESCRIPTION

       The klog.krb5 command obtains a Kerberos v5 ticket from a Kerberos KDC
       and, from the ticket, an AFS token and then stores it in the Cache
       Manager.  The Cache Manager keeps the token 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) on the local
       file system.

       By default, the command interpreter obtains a token for the AFS user
       name that matches the issuer’s local user name.  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.  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.

       By default, the command interpreter obtains a Kerberos ticket for the
       local realm.  To specify a different Kerberos realm, include the -k
       argument.  The Kerberos realm name need not match the AFS cell name.
       klog.krb5 will request a ticket for the principal "afs/cell" where cell
       is the cell name for which the user is requesting tokens, falling back
       on the principal "afs" if that principal does not work.

       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
           that argument was given.

       ·   The maximum ticket lifetime recorded for the "afs/cell" principal
           in thet Kerberos database.

       ·   The maximum ticket lifetime recorded in the specified user’s
           Kerberos database entry.

CAUTIONS

       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.  Users should be
       aware that -setpag will not work on some systems, most notably recent
       Linux systems, and using pagsh is preferrable and more reliable.

       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 makes it more difficult (but not impossible) for the local
       superuser to obtain tokens of other users.

       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.krb5 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.krb5 command on the NFS
       client machine.

       Issuing the klog.krb5 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 default value is the local user name.

       -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.  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.

       -k <realm>
           Obtain tickets and tokens from the <realm> Kerberos realm.  If this
           option is not given, klog.krb5 defaults to using the default local
           realm.  The Kerberos realm name need not match the AFS cell name.

       -pipe
           Suppresses all output to the standard output stream, including
           prompts and error messages. The klog.krb5 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.krb5 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]].

       -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 rather than only obtaining
           tokens.  The ticket file will be stored in the default Kerberos
           ticket cache location, which is usually in the /tmp directory of
           the local machine (but depends on the Kerberos implementation
           used).

       -noprdb
           By default, klog.krb5 looks up the user’s AFS ID in the Protection
           Server and associates the token with that AFS ID.  This is helpful
           when looking at the output of commands like tokens but is not
           required.  If this option is given, this behavior is suppressed and
           klog.krb5 will store the token under a generic name.  You may wish
           this if, for example, you have problems contacting the Protection
           Server for an AFS cell for some reason.

       -unwrap
           Normally, klog.krb5 uses the Kerberos service ticket for the AFS
           principal as the AFS token.  If this option is given, klog.krb5
           creates a different, simplified AFS token form based on the service
           ticket (the so-called "rxkad 2b" token).  Normally, this is not
           necessary.  However, if you are using older OpenAFS software that
           cannot handle large ticket sizes in conjunction with Active
           Directory as the Kerberos server, using -unwrap can shrink the AFS
           token size so that older software can handle it more easily.

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

OUTPUT

       If the -tmp flag is included, the following message confirms that a
       Kerberos ticket cache was created:

          Wrote ticket file to /tmp/krb5cc_1000_rENJoZ

       The path to the cache will vary, of course.

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.

          % klog.krb5
          Password for user@EXAMPLE.ORG:

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

          % klog.krb5 -principal admin -cell test.abc.com
          Password for admin@ABC.COM:

       In the following, the issuer requests a ticket lifetime of 104 hours 30
       minutes (4 days 8 hours 30 minutes).

          % klog.krb5 -lifetime 104:30
          Password for user@EXAMPLE.ORG:

PRIVILEGE REQUIRED

       None

SEE ALSO

       aklog(1), fs_exportafs(1), pagsh(1), tokens(1)

COPYRIGHT

       IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

       This documentation is covered by the IBM Public License Version 1.0.
       It was converted from HTML to POD by software written by Chas Williams
       and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.