kinit(1)
NAME
kinit - obtain and cache Kerberos ticket-granting ticket
SYNOPSIS
kinit [-V] [-l lifetime] [-s start_time] [-r renewable_life] [-p | -P] [-f | -F] [-a] [-A] [-C] [-E] [-v] [-R] [-k [-t keytab_file]] [-c cache_name] [-n] [-S service_name] [-I input_ccache] [-T armor_ccache] [-X attribute[=value]] [principal]
DESCRIPTION
kinit obtains and caches an initial ticket-granting ticket for principal. If principal is absent, kinit chooses an appropriate principal name based on existing credential cache contents or the local username of the user invoking kinit. Some options modify the choice of principal name.
OPTIONS
-V display verbose output.
-l lifetime
(duration string.) Requests a ticket with the lifetime
lifetime.
For example, kinit -l 5:30 or kinit -l 5h30m.
If the -l option is not specified, the default ticket lifetime
(configured by each site) is used. Specifying a ticket lifetime
longer than the maximum ticket lifetime (configured by each
site) will not override the configured maximum ticket lifetime.
-s start_time
(duration string.) Requests a postdated ticket. Postdated
tickets are issued with the invalid flag set, and need to be
resubmitted to the KDC for validation before use.
start_time specifies the duration of the delay before the ticket
can become valid.
-r renewable_life
(duration string.) Requests renewable tickets, with a total
lifetime of renewable_life.
-f requests forwardable tickets.
-F requests non-forwardable tickets.
-p requests proxiable tickets.
-P requests non-proxiable tickets.
-a requests tickets restricted to the host's local address[es].
-A requests tickets not restricted by address.
-C requests canonicalization of the principal name, and allows the
KDC to reply with a different client principal from the one
requested.
-E treats the principal name as an enterprise name (implies the -C
option).
-v requests that the ticket-granting ticket in the cache (with the
invalid flag set) be passed to the KDC for validation. If the
ticket is within its requested time range, the cache is replaced
with the validated ticket.
-R requests renewal of the ticket-granting ticket. Note that an
expired ticket cannot be renewed, even if the ticket is still
within its renewable life.
Note that renewable tickets that have expired as reported by
klist(1) may sometimes be renewed using this option, because the
KDC applies a grace period to account for client-KDC clock skew.
See krb5.conf(5) clockskew setting.
-k [-i | -t keytab_file]
requests a ticket, obtained from a key in the local host's
keytab. The location of the keytab may be specified with the -t
keytab_file option, or with the -i option to specify the use of
the default client keytab; otherwise the default keytab will be
used. By default, a host ticket for the local host is
requested, but any principal may be specified. On a KDC, the
special keytab location KDB: can be used to indicate that kinit
should open the KDC database and look up the key directly. This
permits an administrator to obtain tickets as any principal that
supports authentication based on the key.
-n Requests anonymous processing. Two types of anonymous
principals are supported.
For fully anonymous Kerberos, configure pkinit on the KDC and
configure pkinit_anchors in the client's krb5.conf(5). Then use
the -n option with a principal of the form @REALM (an empty
principal name followed by the at-sign and a realm name). If
permitted by the KDC, an anonymous ticket will be returned.
A second form of anonymous tickets is supported; these
realm-exposed tickets hide the identity of the client but not
the client's realm. For this mode, use kinit -n with a normal
principal name. If supported by the KDC, the principal (but not
realm) will be replaced by the anonymous principal.
As of release 1.8, the MIT Kerberos KDC only supports fully
anonymous operation.
-I input_ccache
Specifies the name of a credentials cache that already contains a
ticket. When obtaining that ticket, if information about how that
ticket was obtained was also stored to the cache, that information
will be used to affect how new credentials are obtained, including
preselecting the same methods of authenticating to the KDC.
-T armor_ccache
Specifies the name of a credentials cache that already contains
a ticket. If supported by the KDC, this cache will be used to
armor the request, preventing offline dictionary attacks and
allowing the use of additional preauthentication mechanisms.
Armoring also makes sure that the response from the KDC is not
modified in transit.
-c cache_name
use cache_name as the Kerberos 5 credentials (ticket) cache
location. If this option is not used, the default cache
location is used.
The default cache location may vary between systems. If the
KRB5CCNAME environment variable is set, its value is used to
locate the default cache. If a principal name is specified and
the type of the default cache supports a collection (such as the
DIR type), an existing cache containing credentials for the
principal is selected or a new one is created and becomes the
new primary cache. Otherwise, any existing contents of the
default cache are destroyed by kinit.
-S service_name
specify an alternate service name to use when getting initial
tickets.
-X attribute[=value]
specify a pre-authentication attribute and value to be
interpreted by pre-authentication modules. The acceptable
attribute and value values vary from module to module. This
option may be specified multiple times to specify multiple
attributes. If no value is specified, it is assumed to be
"yes".
The following attributes are recognized by the PKINIT
pre-authentication mechanism:
X509_user_identity=value
specify where to find user's X509 identity information
X509_anchors=value
specify where to find trusted X509 anchor information
flag_RSA_PROTOCOL[=yes]
specify use of RSA, rather than the default
Diffie-Hellman protocol
ENVIRONMENT
kinit uses the following environment variables:
KRB5CCNAME
Location of the default Kerberos 5 credentials cache, in the
form type:residual. If no type prefix is present, the FILE type
is assumed. The type of the default cache may determine the
availability of a cache collection; for instance, a default
cache of type DIR causes caches within the directory to be
present in the collection.
FILES
FILE:/tmp/krb5cc_%{uid}
default location of Kerberos 5 credentials cache
FILE:/etc/krb5.keytab
default location for the local host's keytab.
SEE ALSO
klist(1), kdestroy(1), kerberos(1)
AUTHOR
MIT
COPYRIGHT
1985-2016, MIT
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