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<h2>On this page </h2>
<ul>
<li><a class="reference internal" href="#">kdc.conf</a><ul>
<li><a class="reference internal" href="#structure">Structure</a></li>
<li><a class="reference internal" href="#sections">Sections</a><ul>
<li><a class="reference internal" href="#kdcdefaults">[kdcdefaults]</a></li>
<li><a class="reference internal" href="#realms">[realms]</a></li>
<li><a class="reference internal" href="#dbdefaults">[dbdefaults]</a></li>
<li><a class="reference internal" href="#dbmodules">[dbmodules]</a></li>
<li><a class="reference internal" href="#logging">[logging]</a></li>
</ul>
</li>
<li><a class="reference internal" href="#pkinit-options">PKINIT options</a></li>
<li><a class="reference internal" href="#encryption-and-salt-types">Encryption and salt types</a></li>
<li><a class="reference internal" href="#sample-kdc-conf-file">Sample kdc.conf File</a></li>
<li><a class="reference internal" href="#files">FILES</a></li>
<li><a class="reference internal" href="#see-also">SEE ALSO</a></li>
</ul>
</li>
</ul>
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<li class="toctree-l2"><a class="reference internal" href="../pkinit.html">PKINIT configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../princ_dns.html">Principal names and DNS</a></li>
<li class="toctree-l2"><a class="reference internal" href="../enctypes.html">Encryption types</a></li>
<li class="toctree-l2"><a class="reference internal" href="../admin_commands/index.html">Administration programs</a></li>
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<div class="section" id="kdc-conf">
<span id="kdc-conf-5"></span><h1>kdc.conf<a class="headerlink" href="#kdc-conf" title="Permalink to this headline">¶</a></h1>
<p>The kdc.conf file supplements <a class="reference internal" href="krb5_conf.html#krb5-conf-5"><em>krb5.conf</em></a> for programs which
are typically only used on a KDC, such as the <a class="reference internal" href="../admin_commands/krb5kdc.html#krb5kdc-8"><em>krb5kdc</em></a> and
<a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a> daemons and the <a class="reference internal" href="../admin_commands/kdb5_util.html#kdb5-util-8"><em>kdb5_util</em></a> program.
Relations documented here may also be specified in krb5.conf; for the
KDC programs mentioned, krb5.conf and kdc.conf will be merged into a
single configuration profile.</p>
<p>Normally, the kdc.conf file is found in the KDC state directory,
<tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt>. You can override the default location by setting the
environment variable <strong>KRB5_KDC_PROFILE</strong>.</p>
<p>Please note that you need to restart the KDC daemon for any configuration
changes to take effect.</p>
<div class="section" id="structure">
<h2>Structure<a class="headerlink" href="#structure" title="Permalink to this headline">¶</a></h2>
<p>The kdc.conf file is set up in the same format as the
<a class="reference internal" href="krb5_conf.html#krb5-conf-5"><em>krb5.conf</em></a> file.</p>
</div>
<div class="section" id="sections">
<h2>Sections<a class="headerlink" href="#sections" title="Permalink to this headline">¶</a></h2>
<p>The kdc.conf file may contain the following sections:</p>
<table border="1" class="docutils">
<colgroup>
<col width="29%" />
<col width="71%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td><a class="reference internal" href="#kdcdefaults"><em>[kdcdefaults]</em></a></td>
<td>Default values for KDC behavior</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="#kdc-realms"><em>[realms]</em></a></td>
<td>Realm-specific database configuration and settings</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="#dbdefaults"><em>[dbdefaults]</em></a></td>
<td>Default database settings</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="#dbmodules"><em>[dbmodules]</em></a></td>
<td>Per-database settings</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="#logging"><em>[logging]</em></a></td>
<td>Controls how Kerberos daemons perform logging</td>
</tr>
</tbody>
</table>
<div class="section" id="kdcdefaults">
<span id="id1"></span><h3>[kdcdefaults]<a class="headerlink" href="#kdcdefaults" title="Permalink to this headline">¶</a></h3>
<p>With one exception, relations in the [kdcdefaults] section specify
default values for realm variables, to be used if the [realms]
subsection does not contain a relation for the tag. See the
<a class="reference internal" href="#kdc-realms"><em>[realms]</em></a> section for the definitions of these relations.</p>
<ul class="simple">
<li><strong>host_based_services</strong></li>
<li><strong>kdc_ports</strong></li>
<li><strong>kdc_tcp_ports</strong></li>
<li><strong>no_host_referral</strong></li>
<li><strong>restrict_anonymous_to_tgt</strong></li>
</ul>
<dl class="docutils">
<dt><strong>kdc_max_dgram_reply_size</strong></dt>
<dd>Specifies the maximum packet size that can be sent over UDP. The
default value is 4096 bytes.</dd>
</dl>
</div>
<div class="section" id="realms">
<span id="kdc-realms"></span><h3>[realms]<a class="headerlink" href="#realms" title="Permalink to this headline">¶</a></h3>
<p>Each tag in the [realms] section is the name of a Kerberos realm.
The value of the tag is a subsection where the relations define KDC
parameters for that particular realm.</p>
<p>For each realm, the following tags may be specified:</p>
<dl class="docutils">
<dt><strong>acl_file</strong></dt>
<dd>(String.) Location of the access control list file that
<a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a> uses to determine which principals are allowed
which permissions on the Kerberos database. The default value is
<tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt><tt class="docutils literal"><span class="pre">/kadm5.acl</span></tt>. For more information on Kerberos ACL
file see <a class="reference internal" href="kadm5_acl.html#kadm5-acl-5"><em>kadm5.acl</em></a>.</dd>
<dt><strong>database_module</strong></dt>
<dd>This relation indicates the name of the configuration section
under <a class="reference internal" href="#dbmodules"><em>[dbmodules]</em></a> for database specific parameters used by
the loadable database library.</dd>
<dt><strong>database_name</strong></dt>
<dd>(String.) This string specifies the location of the Kerberos
database for this realm, if the DB2 back-end is being used. If a
<strong>database_module</strong> is specified for the realm and the
corresponding module contains a <strong>database_name</strong> parameter, that
value will take precedence over this one. The default value is
<tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt><tt class="docutils literal"><span class="pre">/principal</span></tt>.</dd>
<dt><strong>default_principal_expiration</strong></dt>
<dd>(<a class="reference internal" href="../../basic/date_format.html#abstime"><em>Absolute time</em></a> string.) Specifies the default expiration date of
principals created in this realm. The default value is 0, which
means no expiration date.</dd>
<dt><strong>default_principal_flags</strong></dt>
<dd><p class="first">(Flag string.) Specifies the default attributes of principals
created in this realm. The format for this string is a
comma-separated list of flags, with ‘+’ before each flag that
should be enabled and ‘-‘ before each flag that should be
disabled. The <strong>postdateable</strong>, <strong>forwardable</strong>, <strong>tgt-based</strong>,
<strong>renewable</strong>, <strong>proxiable</strong>, <strong>dup-skey</strong>, <strong>allow-tickets</strong>, and
<strong>service</strong> flags default to enabled.</p>
<p>There are a number of possible flags:</p>
<dl class="last docutils">
<dt><strong>allow-tickets</strong></dt>
<dd>Enabling this flag means that the KDC will issue tickets for
this principal. Disabling this flag essentially deactivates
the principal within this realm.</dd>
<dt><strong>dup-skey</strong></dt>
<dd>Enabling this flag allows the principal to obtain a session
key for another user, permitting user-to-user authentication
for this principal.</dd>
<dt><strong>forwardable</strong></dt>
<dd>Enabling this flag allows the principal to obtain forwardable
tickets.</dd>
<dt><strong>hwauth</strong></dt>
<dd>If this flag is enabled, then the principal is required to
preauthenticate using a hardware device before receiving any
tickets.</dd>
<dt><strong>no-auth-data-required</strong></dt>
<dd>Enabling this flag prevents PAC data from being added to
service tickets for the principal.</dd>
<dt><strong>ok-as-delegate</strong></dt>
<dd>If this flag is enabled, it hints the client that credentials
can and should be delegated when authenticating to the
service.</dd>
<dt><strong>ok-to-auth-as-delegate</strong></dt>
<dd>Enabling this flag allows the principal to use S4USelf tickets.</dd>
<dt><strong>postdateable</strong></dt>
<dd>Enabling this flag allows the principal to obtain postdateable
tickets.</dd>
<dt><strong>preauth</strong></dt>
<dd>If this flag is enabled on a client principal, then that
principal is required to preauthenticate to the KDC before
receiving any tickets. On a service principal, enabling this
flag means that service tickets for this principal will only
be issued to clients with a TGT that has the preauthenticated
bit set.</dd>
<dt><strong>proxiable</strong></dt>
<dd>Enabling this flag allows the principal to obtain proxy
tickets.</dd>
<dt><strong>pwchange</strong></dt>
<dd>Enabling this flag forces a password change for this
principal.</dd>
<dt><strong>pwservice</strong></dt>
<dd>If this flag is enabled, it marks this principal as a password
change service. This should only be used in special cases,
for example, if a user’s password has expired, then the user
has to get tickets for that principal without going through
the normal password authentication in order to be able to
change the password.</dd>
<dt><strong>renewable</strong></dt>
<dd>Enabling this flag allows the principal to obtain renewable
tickets.</dd>
<dt><strong>service</strong></dt>
<dd>Enabling this flag allows the the KDC to issue service tickets
for this principal.</dd>
<dt><strong>tgt-based</strong></dt>
<dd>Enabling this flag allows a principal to obtain tickets based
on a ticket-granting-ticket, rather than repeating the
authentication process that was used to obtain the TGT.</dd>
</dl>
</dd>
<dt><strong>dict_file</strong></dt>
<dd>(String.) Location of the dictionary file containing strings that
are not allowed as passwords. If none is specified or if there is
no policy assigned to the principal, no dictionary checks of
passwords will be performed.</dd>
<dt><strong>host_based_services</strong></dt>
<dd>(Whitespace- or comma-separated list.) Lists services which will
get host-based referral processing even if the server principal is
not marked as host-based by the client.</dd>
<dt><strong>iprop_enable</strong></dt>
<dd>(Boolean value.) Specifies whether incremental database
propagation is enabled. The default value is false.</dd>
<dt><strong>iprop_master_ulogsize</strong></dt>
<dd>(Integer.) Specifies the maximum number of log entries to be
retained for incremental propagation. The maximum value is 2500;
the default value is 1000.</dd>
<dt><strong>iprop_slave_poll</strong></dt>
<dd>(Delta time string.) Specifies how often the slave KDC polls for
new updates from the master. The default value is <tt class="docutils literal"><span class="pre">2m</span></tt> (that
is, two minutes).</dd>
<dt><strong>iprop_port</strong></dt>
<dd>(Port number.) Specifies the port number to be used for
incremental propagation. This is required in both master and
slave configuration files.</dd>
<dt><strong>iprop_resync_timeout</strong></dt>
<dd>(Delta time string.) Specifies the amount of time to wait for a
full propagation to complete. This is optional in configuration
files, and is used by slave KDCs only. The default value is 5
minutes (<tt class="docutils literal"><span class="pre">5m</span></tt>).</dd>
<dt><strong>iprop_logfile</strong></dt>
<dd>(File name.) Specifies where the update log file for the realm
database is to be stored. The default is to use the
<strong>database_name</strong> entry from the realms section of the krb5 config
file, with <tt class="docutils literal"><span class="pre">.ulog</span></tt> appended. (NOTE: If <strong>database_name</strong> isn’t
specified in the realms section, perhaps because the LDAP database
back end is being used, or the file name is specified in the
[dbmodules] section, then the hard-coded default for
<strong>database_name</strong> is used. Determination of the <strong>iprop_logfile</strong>
default value will not use values from the [dbmodules] section.)</dd>
<dt><strong>kadmind_port</strong></dt>
<dd>(Port number.) Specifies the port on which the <a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a>
daemon is to listen for this realm. The assigned port for kadmind
is 749, which is used by default.</dd>
<dt><strong>key_stash_file</strong></dt>
<dd>(String.) Specifies the location where the master key has been
stored (via kdb5_util stash). The default is <tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt><tt class="docutils literal"><span class="pre">/.k5.REALM</span></tt>, where <em>REALM</em> is the Kerberos realm.</dd>
<dt><strong>kdc_ports</strong></dt>
<dd>(Whitespace- or comma-separated list.) Lists the ports on which
the Kerberos server should listen for UDP requests, as a
comma-separated list of integers. The default value is
<tt class="docutils literal"><span class="pre">88,750</span></tt>, which are the assigned Kerberos port and the port
historically used by Kerberos V4.</dd>
<dt><strong>kdc_tcp_ports</strong></dt>
<dd><p class="first">(Whitespace- or comma-separated list.) Lists the ports on which
the Kerberos server should listen for TCP connections, as a
comma-separated list of integers. If this relation is not
specified, the compiled-in default is not to listen for TCP
connections at all.</p>
<p class="last">If you wish to change this (note that the current implementation
has little protection against denial-of-service attacks), the
standard port number assigned for Kerberos TCP traffic is port 88.</p>
</dd>
<dt><strong>master_key_name</strong></dt>
<dd>(String.) Specifies the name of the principal associated with the
master key. The default is <tt class="docutils literal"><span class="pre">K/M</span></tt>.</dd>
<dt><strong>master_key_type</strong></dt>
<dd>(Key type string.) Specifies the master key’s key type. The
default value for this is <tt class="docutils literal"><span class="pre">aes256-cts-hmac-sha1-96</span></tt>. For a list of all possible
values, see <a class="reference internal" href="#encryption-and-salt-types"><em>Encryption and salt types</em></a>.</dd>
<dt><strong>max_life</strong></dt>
<dd>(<a class="reference internal" href="../../basic/date_format.html#duration"><em>Time duration</em></a> string.) Specifies the maximum time period for
which a ticket may be valid in this realm. The default value is
24 hours.</dd>
<dt><strong>max_renewable_life</strong></dt>
<dd>(<a class="reference internal" href="../../basic/date_format.html#duration"><em>Time duration</em></a> string.) Specifies the maximum time period
during which a valid ticket may be renewed in this realm.
The default value is 0.</dd>
<dt><strong>no_host_referral</strong></dt>
<dd>(Whitespace- or comma-separated list.) Lists services to block
from getting host-based referral processing, even if the client
marks the server principal as host-based or the service is also
listed in <strong>host_based_services</strong>. <tt class="docutils literal"><span class="pre">no_host_referral</span> <span class="pre">=</span> <span class="pre">*</span></tt> will
disable referral processing altogether.</dd>
<dt><strong>des_crc_session_supported</strong></dt>
<dd>(Boolean value). If set to true, the KDC will assume that service
principals support des-cbc-crc for session key enctype negotiation
purposes. If <strong>allow_weak_crypto</strong> in <a class="reference internal" href="krb5_conf.html#libdefaults"><em>[libdefaults]</em></a> is
false, or if des-cbc-crc is not a permitted enctype, then this
variable has no effect. Defaults to true.</dd>
<dt><strong>reject_bad_transit</strong></dt>
<dd><p class="first">(Boolean value.) If set to true, the KDC will check the list of
transited realms for cross-realm tickets against the transit path
computed from the realm names and the capaths section of its
<a class="reference internal" href="krb5_conf.html#krb5-conf-5"><em>krb5.conf</em></a> file; if the path in the ticket to be issued
contains any realms not in the computed path, the ticket will not
be issued, and an error will be returned to the client instead.
If this value is set to false, such tickets will be issued
anyways, and it will be left up to the application server to
validate the realm transit path.</p>
<p>If the disable-transited-check flag is set in the incoming
request, this check is not performed at all. Having the
<strong>reject_bad_transit</strong> option will cause such ticket requests to
be rejected always.</p>
<p>This transit path checking and config file option currently apply
only to TGS requests.</p>
<p class="last">The default value is true.</p>
</dd>
<dt><strong>restrict_anonymous_to_tgt</strong></dt>
<dd>(Boolean value.) If set to true, the KDC will reject ticket
requests from anonymous principals to service principals other
than the realm’s ticket-granting service. This option allows
anonymous PKINIT to be enabled for use as FAST armor tickets
without allowing anonymous authentication to services. The
default value is false.</dd>
<dt><strong>supported_enctypes</strong></dt>
<dd>(List of <em>key</em>:<em>salt</em> strings.) Specifies the default key/salt
combinations of principals for this realm. Any principals created
through <a class="reference internal" href="../admin_commands/kadmin_local.html#kadmin-1"><em>kadmin</em></a> will have keys of these types. The
default value for this tag is <tt class="docutils literal"><span class="pre">aes256-cts-hmac-sha1-96:normal</span> <span class="pre">aes128-cts-hmac-sha1-96:normal</span> <span class="pre">des3-cbc-sha1:normal</span> <span class="pre">arcfour-hmac-md5:normal</span></tt>. For lists of
possible values, see <a class="reference internal" href="#encryption-and-salt-types"><em>Encryption and salt types</em></a>.</dd>
</dl>
</div>
<div class="section" id="dbdefaults">
<span id="id2"></span><h3>[dbdefaults]<a class="headerlink" href="#dbdefaults" title="Permalink to this headline">¶</a></h3>
<p>The [dbdefaults] section specifies default values for some database
parameters, to be used if the [dbmodules] subsection does not contain
a relation for the tag. See the <a class="reference internal" href="#dbmodules"><em>[dbmodules]</em></a> section for the
definitions of these relations.</p>
<ul class="simple">
<li><strong>ldap_kerberos_container_dn</strong></li>
<li><strong>ldap_kdc_dn</strong></li>
<li><strong>ldap_kadmind_dn</strong></li>
<li><strong>ldap_service_password_file</strong></li>
<li><strong>ldap_servers</strong></li>
<li><strong>ldap_conns_per_server</strong></li>
</ul>
</div>
<div class="section" id="dbmodules">
<span id="id3"></span><h3>[dbmodules]<a class="headerlink" href="#dbmodules" title="Permalink to this headline">¶</a></h3>
<p>The [dbmodules] section contains parameters used by the KDC database
library and database modules.</p>
<p>The following tag may be specified in the [dbmodules] section:</p>
<dl class="docutils">
<dt><strong>db_module_dir</strong></dt>
<dd>This tag controls where the plugin system looks for modules. The
value should be an absolute path.</dd>
</dl>
<p>Other tags in the [dbmodules] section name a configuration subsection
for parameters which can be referred to by a realm’s
<strong>database_module</strong> parameter. The following tags may be specified in
the subsection:</p>
<dl class="docutils">
<dt><strong>database_name</strong></dt>
<dd>This DB2-specific tag indicates the location of the database in
the filesystem. The default is <tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt><tt class="docutils literal"><span class="pre">/principal</span></tt>.</dd>
<dt><strong>db_library</strong></dt>
<dd>This tag indicates the name of the loadable database module. The
value should be <tt class="docutils literal"><span class="pre">db2</span></tt> for the DB2 module and <tt class="docutils literal"><span class="pre">kldap</span></tt> for the
LDAP module.</dd>
<dt><strong>disable_last_success</strong></dt>
<dd>If set to <tt class="docutils literal"><span class="pre">true</span></tt>, suppresses KDC updates to the “Last successful
authentication” field of principal entries requiring
preauthentication. Setting this flag may improve performance.
(Principal entries which do not require preauthentication never
update the “Last successful authentication” field.). First
introduced in version 1.9.</dd>
<dt><strong>disable_lockout</strong></dt>
<dd>If set to <tt class="docutils literal"><span class="pre">true</span></tt>, suppresses KDC updates to the “Last failed
authentication” and “Failed password attempts” fields of principal
entries requiring preauthentication. Setting this flag may
improve performance, but also disables account lockout. First
introduced in version 1.9.</dd>
<dt><strong>ldap_conns_per_server</strong></dt>
<dd>This LDAP-specific tag indicates the number of connections to be
maintained per LDAP server.</dd>
<dt><strong>ldap_kadmind_dn</strong></dt>
<dd>This LDAP-specific tag indicates the default bind DN for the
<a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a> daemon. kadmind does a login to the directory
as this object. This object should have the rights to read and
write the Kerberos data in the LDAP database.</dd>
<dt><strong>ldap_kdc_dn</strong></dt>
<dd>This LDAP-specific tag indicates the default bind DN for the
<a class="reference internal" href="../admin_commands/krb5kdc.html#krb5kdc-8"><em>krb5kdc</em></a> daemon. The KDC does a login to the directory
as this object. This object should have the rights to read the
Kerberos data in the LDAP database, and to write data unless
<strong>disable_lockout</strong> and <strong>disable_last_success</strong> are true.</dd>
<dt><strong>ldap_kerberos_container_dn</strong></dt>
<dd>This LDAP-specific tag indicates the DN of the container object
where the realm objects will be located.</dd>
<dt><strong>ldap_servers</strong></dt>
<dd>This LDAP-specific tag indicates the list of LDAP servers that the
Kerberos servers can connect to. The list of LDAP servers is
whitespace-separated. The LDAP server is specified by a LDAP URI.
It is recommended to use <tt class="docutils literal"><span class="pre">ldapi:</span></tt> or <tt class="docutils literal"><span class="pre">ldaps:</span></tt> URLs to connect
to the LDAP server.</dd>
<dt><strong>ldap_service_password_file</strong></dt>
<dd>This LDAP-specific tag indicates the file containing the stashed
passwords (created by <tt class="docutils literal"><span class="pre">kdb5_ldap_util</span> <span class="pre">stashsrvpw</span></tt>) for the
<strong>ldap_kadmind_dn</strong> and <strong>ldap_kdc_dn</strong> objects. This file must
be kept secure.</dd>
</dl>
</div>
<div class="section" id="logging">
<span id="id4"></span><h3>[logging]<a class="headerlink" href="#logging" title="Permalink to this headline">¶</a></h3>
<p>The [logging] section indicates how <a class="reference internal" href="../admin_commands/krb5kdc.html#krb5kdc-8"><em>krb5kdc</em></a> and
<a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a> perform logging. The keys in this section are
daemon names, which may be one of:</p>
<dl class="docutils">
<dt><strong>admin_server</strong></dt>
<dd>Specifies how <a class="reference internal" href="../admin_commands/kadmind.html#kadmind-8"><em>kadmind</em></a> performs logging.</dd>
<dt><strong>kdc</strong></dt>
<dd>Specifies how <a class="reference internal" href="../admin_commands/krb5kdc.html#krb5kdc-8"><em>krb5kdc</em></a> performs logging.</dd>
<dt><strong>default</strong></dt>
<dd>Specifies how either daemon performs logging in the absence of
relations specific to the daemon.</dd>
</dl>
<p>Values are of the following forms:</p>
<dl class="docutils">
<dt><strong>FILE=</strong><em>filename</em> or <strong>FILE:</strong><em>filename</em></dt>
<dd>This value causes the daemon’s logging messages to go to the
<em>filename</em>. If the <tt class="docutils literal"><span class="pre">=</span></tt> form is used, the file is overwritten.
If the <tt class="docutils literal"><span class="pre">:</span></tt> form is used, the file is appended to.</dd>
<dt><strong>STDERR</strong></dt>
<dd>This value causes the daemon’s logging messages to go to its
standard error stream.</dd>
<dt><strong>CONSOLE</strong></dt>
<dd>This value causes the daemon’s logging messages to go to the
console, if the system supports it.</dd>
<dt><strong>DEVICE=</strong><em><devicename></em></dt>
<dd>This causes the daemon’s logging messages to go to the specified
device.</dd>
<dt><strong>SYSLOG</strong>[<strong>:</strong><em>severity</em>[<strong>:</strong><em>facility</em>]]</dt>
<dd><p class="first">This causes the daemon’s logging messages to go to the system log.</p>
<p>The severity argument specifies the default severity of system log
messages. This may be any of the following severities supported
by the syslog(3) call, minus the <tt class="docutils literal"><span class="pre">LOG_</span></tt> prefix: <strong>EMERG</strong>,
<strong>ALERT</strong>, <strong>CRIT</strong>, <strong>ERR</strong>, <strong>WARNING</strong>, <strong>NOTICE</strong>, <strong>INFO</strong>,
and <strong>DEBUG</strong>.</p>
<p>The facility argument specifies the facility under which the
messages are logged. This may be any of the following facilities
supported by the syslog(3) call minus the LOG_ prefix: <strong>KERN</strong>,
<strong>USER</strong>, <strong>MAIL</strong>, <strong>DAEMON</strong>, <strong>AUTH</strong>, <strong>LPR</strong>, <strong>NEWS</strong>,
<strong>UUCP</strong>, <strong>CRON</strong>, and <strong>LOCAL0</strong> through <strong>LOCAL7</strong>.</p>
<p class="last">If no severity is specified, the default is <strong>ERR</strong>. If no
facility is specified, the default is <strong>AUTH</strong>.</p>
</dd>
</dl>
<p>In the following example, the logging messages from the KDC will go to
the console and to the system log under the facility LOG_DAEMON with
default severity of LOG_INFO; and the logging messages from the
administrative server will be appended to the file
<tt class="docutils literal"><span class="pre">/var/adm/kadmin.log</span></tt> and sent to the device <tt class="docutils literal"><span class="pre">/dev/tty04</span></tt>.</p>
<blockquote>
<div><div class="highlight-python"><pre>[logging]
kdc = CONSOLE
kdc = SYSLOG:INFO:DAEMON
admin_server = FILE:/var/adm/kadmin.log
admin_server = DEVICE=/dev/tty04</pre>
</div>
</div></blockquote>
</div>
</div>
<div class="section" id="pkinit-options">
<h2>PKINIT options<a class="headerlink" href="#pkinit-options" title="Permalink to this headline">¶</a></h2>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The following are pkinit-specific options. These values may
be specified in [kdcdefaults] as global defaults, or within
a realm-specific subsection of [realms]. Also note that a
realm-specific value over-rides, does not add to, a generic
[kdcdefaults] specification. The search order is:</p>
</div>
<ol class="arabic">
<li><p class="first">realm-specific subsection of [realms],</p>
<blockquote>
<div><div class="highlight-python"><pre>[realms]
EXAMPLE.COM = {
pkinit_anchors = FILE:/usr/local/example.com.crt
}</pre>
</div>
</div></blockquote>
</li>
<li><p class="first">generic value in the [kdcdefaults] section.</p>
<blockquote>
<div><div class="highlight-python"><pre>[kdcdefaults]
pkinit_anchors = DIR:/usr/local/generic_trusted_cas/</pre>
</div>
</div></blockquote>
</li>
</ol>
<p>For information about the syntax of some of these options, see
<a class="reference internal" href="krb5_conf.html#pkinit-identity"><em>Specifying PKINIT identity information</em></a> in
<a class="reference internal" href="krb5_conf.html#krb5-conf-5"><em>krb5.conf</em></a>.</p>
<dl class="docutils">
<dt><strong>pkinit_anchors</strong></dt>
<dd>Specifies the location of trusted anchor (root) certificates which
the KDC trusts to sign client certificates. This option is
required if pkinit is to be supported by the KDC. This option may
be specified multiple times.</dd>
<dt><strong>pkinit_dh_min_bits</strong></dt>
<dd>Specifies the minimum number of bits the KDC is willing to accept
for a client’s Diffie-Hellman key. The default is 2048.</dd>
<dt><strong>pkinit_allow_upn</strong></dt>
<dd><p class="first">Specifies that the KDC is willing to accept client certificates
with the Microsoft UserPrincipalName (UPN) Subject Alternative
Name (SAN). This means the KDC accepts the binding of the UPN in
the certificate to the Kerberos principal name. The default value
is false.</p>
<p class="last">Without this option, the KDC will only accept certificates with
the id-pkinit-san as defined in <span class="target" id="index-0"></span><a class="rfc reference external" href="http://tools.ietf.org/html/rfc4556.html"><strong>RFC 4556</strong></a>. There is currently
no option to disable SAN checking in the KDC.</p>
</dd>
<dt><strong>pkinit_eku_checking</strong></dt>
<dd><p class="first">This option specifies what Extended Key Usage (EKU) values the KDC
is willing to accept in client certificates. The values
recognized in the kdc.conf file are:</p>
<dl class="last docutils">
<dt><strong>kpClientAuth</strong></dt>
<dd>This is the default value and specifies that client
certificates must have the id-pkinit-KPClientAuth EKU as
defined in <span class="target" id="index-1"></span><a class="rfc reference external" href="http://tools.ietf.org/html/rfc4556.html"><strong>RFC 4556</strong></a>.</dd>
<dt><strong>scLogin</strong></dt>
<dd>If scLogin is specified, client certificates with the
Microsoft Smart Card Login EKU (id-ms-kp-sc-logon) will be
accepted.</dd>
<dt><strong>none</strong></dt>
<dd>If none is specified, then client certificates will not be
checked to verify they have an acceptable EKU. The use of
this option is not recommended.</dd>
</dl>
</dd>
<dt><strong>pkinit_identity</strong></dt>
<dd>Specifies the location of the KDC’s X.509 identity information.
This option is required if pkinit is to be supported by the KDC.</dd>
<dt><strong>pkinit_kdc_ocsp</strong></dt>
<dd>Specifies the location of the KDC’s OCSP.</dd>
<dt><strong>pkinit_mapping_file</strong></dt>
<dd>Specifies the name of the ACL pkinit mapping file. This file maps
principals to the certificates that they can use.</dd>
<dt><strong>pkinit_pool</strong></dt>
<dd>Specifies the location of intermediate certificates which may be
used by the KDC to complete the trust chain between a client’s
certificate and a trusted anchor. This option may be specified
multiple times.</dd>
<dt><strong>pkinit_revoke</strong></dt>
<dd>Specifies the location of Certificate Revocation List (CRL)
information to be used by the KDC when verifying the validity of
client certificates. This option may be specified multiple times.</dd>
<dt><strong>pkinit_require_crl_checking</strong></dt>
<dd><p class="first">The default certificate verification process will always check the
available revocation information to see if a certificate has been
revoked. If a match is found for the certificate in a CRL,
verification fails. If the certificate being verified is not
listed in a CRL, or there is no CRL present for its issuing CA,
and <strong>pkinit_require_crl_checking</strong> is false, then verification
succeeds.</p>
<p>However, if <strong>pkinit_require_crl_checking</strong> is true and there is
no CRL information available for the issuing CA, then verification
fails.</p>
<p class="last"><strong>pkinit_require_crl_checking</strong> should be set to true if the
policy is such that up-to-date CRLs must be present for every CA.</p>
</dd>
</dl>
</div>
<div class="section" id="encryption-and-salt-types">
<span id="id5"></span><h2>Encryption and salt types<a class="headerlink" href="#encryption-and-salt-types" title="Permalink to this headline">¶</a></h2>
<p>Any tag in the configuration files which requires a list of encryption
types can be set to some combination of the following strings.
Encryption types marked as “weak” are available for compatibility but
not recommended for use.</p>
<table border="1" class="docutils">
<colgroup>
<col width="44%" />
<col width="56%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td>des-cbc-crc</td>
<td>DES cbc mode with CRC-32 (weak)</td>
</tr>
<tr class="row-even"><td>des-cbc-md4</td>
<td>DES cbc mode with RSA-MD4 (weak)</td>
</tr>
<tr class="row-odd"><td>des-cbc-md5</td>
<td>DES cbc mode with RSA-MD5 (weak)</td>
</tr>
<tr class="row-even"><td>des-cbc-raw</td>
<td>DES cbc mode raw (weak)</td>
</tr>
<tr class="row-odd"><td>des3-cbc-raw</td>
<td>Triple DES cbc mode raw (weak)</td>
</tr>
<tr class="row-even"><td>des3-cbc-sha1 des3-hmac-sha1 des3-cbc-sha1-kd</td>
<td>Triple DES cbc mode with HMAC/sha1</td>
</tr>
<tr class="row-odd"><td>des-hmac-sha1</td>
<td>DES with HMAC/sha1 (weak)</td>
</tr>
<tr class="row-even"><td>aes256-cts-hmac-sha1-96 aes256-cts AES-256</td>
<td>CTS mode with 96-bit SHA-1 HMAC</td>
</tr>
<tr class="row-odd"><td>aes128-cts-hmac-sha1-96 aes128-cts AES-128</td>
<td>CTS mode with 96-bit SHA-1 HMAC</td>
</tr>
<tr class="row-even"><td>arcfour-hmac rc4-hmac arcfour-hmac-md5</td>
<td>RC4 with HMAC/MD5</td>
</tr>
<tr class="row-odd"><td>arcfour-hmac-exp rc4-hmac-exp arcfour-hmac-md5-exp</td>
<td>Exportable RC4 with HMAC/MD5 (weak)</td>
</tr>
<tr class="row-even"><td>camellia256-cts-cmac camellia256-cts</td>
<td>Camellia-256 CTS mode with CMAC</td>
</tr>
<tr class="row-odd"><td>camellia128-cts-cmac camellia128-cts</td>
<td>Camellia-128 CTS mode with CMAC</td>
</tr>
<tr class="row-even"><td>des</td>
<td>The DES family: des-cbc-crc, des-cbc-md5, and des-cbc-md4 (weak)</td>
</tr>
<tr class="row-odd"><td>des3</td>
<td>The triple DES family: des3-cbc-sha1</td>
</tr>
<tr class="row-even"><td>aes</td>
<td>The AES family: aes256-cts-hmac-sha1-96 and aes128-cts-hmac-sha1-96</td>
</tr>
<tr class="row-odd"><td>rc4</td>
<td>The RC4 family: arcfour-hmac</td>
</tr>
<tr class="row-even"><td>camellia</td>
<td>The Camellia family: camellia256-cts-cmac and camellia128-cts-cmac</td>
</tr>
</tbody>
</table>
<p>The string <strong>DEFAULT</strong> can be used to refer to the default set of
types for the variable in question. Types or families can be removed
from the current list by prefixing them with a minus sign (“-”).
Types or families can be prefixed with a plus sign (“+”) for symmetry;
it has the same meaning as just listing the type or family. For
example, “<tt class="docutils literal"><span class="pre">DEFAULT</span> <span class="pre">-des</span></tt>” would be the default set of encryption
types with DES types removed, and “<tt class="docutils literal"><span class="pre">des3</span> <span class="pre">DEFAULT</span></tt>” would be the
default set of encryption types with triple DES types moved to the
front.</p>
<p>While <strong>aes128-cts</strong> and <strong>aes256-cts</strong> are supported for all Kerberos
operations, they are not supported by very old versions of our GSSAPI
implementation (krb5-1.3.1 and earlier). Services running versions of
krb5 without AES support must not be given AES keys in the KDC
database.</p>
<p>Kerberos keys for users are usually derived from passwords. To ensure
that people who happen to pick the same password do not have the same
key, Kerberos 5 incorporates more information into the key using
something called a salt. The supported salt types are as follows:</p>
<table border="1" class="docutils">
<colgroup>
<col width="21%" />
<col width="79%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td>normal</td>
<td>default for Kerberos Version 5</td>
</tr>
<tr class="row-even"><td>v4</td>
<td>the only type used by Kerberos Version 4 (no salt)</td>
</tr>
<tr class="row-odd"><td>norealm</td>
<td>same as the default, without using realm information</td>
</tr>
<tr class="row-even"><td>onlyrealm</td>
<td>uses only realm information as the salt</td>
</tr>
<tr class="row-odd"><td>afs3</td>
<td>AFS version 3, only used for compatibility with Kerberos 4 in AFS</td>
</tr>
<tr class="row-even"><td>special</td>
<td>generate a random salt</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="sample-kdc-conf-file">
<h2>Sample kdc.conf File<a class="headerlink" href="#sample-kdc-conf-file" title="Permalink to this headline">¶</a></h2>
<p>Here’s an example of a kdc.conf file:</p>
<blockquote>
<div><div class="highlight-python"><pre>[kdcdefaults]
kdc_ports = 88
[realms]
ATHENA.MIT.EDU = {
kadmind_port = 749
max_life = 12h 0m 0s
max_renewable_life = 7d 0h 0m 0s
master_key_type = des3-hmac-sha1
supported_enctypes = des3-hmac-sha1:normal des-cbc-crc:normal des-cbc-crc:v4
database_module = openldap_ldapconf
}
[logging]
kdc = FILE:/usr/local/var/krb5kdc/kdc.log
admin_server = FILE:/usr/local/var/krb5kdc/kadmin.log
[dbdefaults]
ldap_kerberos_container_dn = cn=krbcontainer,dc=mit,dc=edu
[dbmodules]
openldap_ldapconf = {
db_library = kldap
disable_last_success = true
ldap_kdc_dn = "cn=krbadmin,dc=mit,dc=edu"
# this object needs to have read rights on
# the realm container and principal subtrees
ldap_kadmind_dn = "cn=krbadmin,dc=mit,dc=edu"
# this object needs to have read and write rights on
# the realm container and principal subtrees
ldap_service_password_file = /etc/kerberos/service.keyfile
ldap_servers = ldaps://kerberos.mit.edu
ldap_conns_per_server = 5
}</pre>
</div>
</div></blockquote>
</div>
<div class="section" id="files">
<h2>FILES<a class="headerlink" href="#files" title="Permalink to this headline">¶</a></h2>
<p><tt class="docutils literal"><span class="pre">/var/lib</span></tt><tt class="docutils literal"><span class="pre">/krb5kdc</span></tt><tt class="docutils literal"><span class="pre">/kdc.conf</span></tt></p>
</div>
<div class="section" id="see-also">
<h2>SEE ALSO<a class="headerlink" href="#see-also" title="Permalink to this headline">¶</a></h2>
<p><a class="reference internal" href="krb5_conf.html#krb5-conf-5"><em>krb5.conf</em></a>, <a class="reference internal" href="../admin_commands/krb5kdc.html#krb5kdc-8"><em>krb5kdc</em></a>, <a class="reference internal" href="kadm5_acl.html#kadm5-acl-5"><em>kadm5.acl</em></a></p>
</div>
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