kinit - obtain and cache Kerberos ticket-granting ticket
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]
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.
- -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.
- -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:
See kerberos(7) for a description of Kerberos environment
variables.