path: root/third_party/heimdal/lib/krb5/krb5.conf.5

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.Dd May  4, 2005
.Dt KRB5.CONF 5
.Os HEIMDAL
.Sh NAME
.Nm krb5.conf
.Nd configuration file for Kerberos 5
.Sh SYNOPSIS
.In krb5.h
.Sh DESCRIPTION
The
.Nm
file specifies several configuration parameters for the Kerberos 5
library, as well as for some programs.
.Pp
The file consists of one or more sections, containing a number of
bindings.
The value of each binding can be either a string or a list of other
bindings.
The grammar looks like:
.Bd -literal -offset indent
file:
	/* empty */
	sections
        includes

sections:
	section sections
	section

section:
	'[' section_name ']' bindings

section_name:
	STRING

bindings:
	binding bindings
	binding

binding:
	name '=' STRING
	name '=' '{' bindings '}'

name:
	STRING

includes:
	'include' path
	'includedir' path

path: STRING

.Ed
.Li STRINGs
consists of one or more non-whitespace characters.
.Pp
Files and directories may be included by absolute path, with percent
token expansion (see the TOKEN EXPANSION section).  Including a
directory causes all files in the directory to be included as if each
file had been included separately, but only files whose names consist of
alphanumeric, hyphen, and underscore are included, though they may also
end in '.conf'.
.Pp
STRINGs that are specified later in this man-page uses the following
notation.
.Bl -tag -width "xxx" -offset indent
.It boolean
values can be either yes/true or no/false.
.It time
values can be a list of year, month, day, hour, min, second.
Example: 1 month 2 days 30 min.
If no unit is given, seconds is assumed.
.It etypes
valid encryption types are: des-cbc-crc, des-cbc-md4, des-cbc-md5,
des3-cbc-sha1, arcfour-hmac-md5, aes128-cts-hmac-sha1-96, aes256-cts-hmac-sha1-96,
aes128-cts-hmac-sha256-128, and aes256-cts-hmac-sha384-192.
.It address
an address can be either a IPv4 or a IPv6 address.
.El
.Pp
Currently recognised sections and bindings are:
.Bl -tag -width "xxx" -offset indent
.It Li [appdefaults]
Specifies the default values to be used for Kerberos applications.
You can specify defaults per application, realm, or a combination of
these.
The preference order is:
.Bl -enum -compact
.It
.Va application Va realm Va option
.It
.Va application Va option
.It
.Va realm Va option
.It
.Va option
.El
.Pp
The supported options are:
.Bl -tag -width "xxx" -offset indent
.It Li forwardable = Va boolean
When obtaining initial credentials, make the credentials forwardable.
.It Li proxiable = Va boolean
When obtaining initial credentials, make the credentials proxiable.
.It Li no-addresses = Va boolean
When obtaining initial credentials, request them for an empty set of
addresses, making the tickets valid from any address.
.It Li ticket_lifetime = Va time
Default ticket lifetime.
.It Li renew_lifetime = Va time
Default renewable ticket lifetime.
.It Li encrypt = Va boolean
Use encryption, when available.
.It Li forward = Va boolean
Forward credentials to remote host (for
.Xr rsh 1 ,
.Xr telnet 1 ,
etc).
.It Li historical_anon_pkinit = Va boolean
Enable legacy anonymous pkinit command-line syntax.
With this option set to
.Li true,
the
.Xr kinit 1
.Fl Fl anonymous
command with no principal argument specified will request an anonymous pkinit
ticket from the default realm.
If a principal argument is specified, it is used as an explicit realm name for
anonymous pkinit even without an
.Li @
prefix.
.It Li delegate-destination-tgt = Va boolean
When forwarding credentials to a remote host, forward a TGT for the
realm of the destination host rather than a TGT for the user's realm.
This is useful when hosts in the remote realm should not or cannot
(e.g. firewalled from user realm's KDC) obtain tickets for services
in the user's realm. When the user's realm and the host's realm are
the same, this parameter has no effect.  The setting can be applied
to a single realm as follows:
.Bd -literal -offset indent
EXAMPLE.COM = {
	delegate-destination-tgt = true
}
.Ed
.It Li pkinit_pool = Va HX509-STORE
This is a multi-valued parameter naming one or more stores of
intermediate certification authority (CA) certificates for the
client's end entity certificate.
.It Li pkinit_anchors = Va HX509-STORE ...
This is a multi-valued parameter naming one or more stores of
anchors for PKINIT KDC certificates.
.It Li pkinit_revoke = Va HX509-STORE ...
This is a multi-valued parameter naming one or more stores of
CRLs for the issuers of PKINIT KDC certificates.
Only the first valid CRL for a particular issuer will be checked.
If no CRLs are configured, then CRLs will not be checked.
This is because hx509 currently lacks support.
.El
.It Li [libdefaults]
.Bl -tag -width "xxx" -offset indent
.It Li default_realm = Va REALM
Default realm to use, this is also known as your
.Dq local realm .
The default is the result of
.Fn krb5_get_host_realm "local hostname" .
.It Li allow_weak_crypto = Va boolean
are weak crypto algorithms allowed to be used, among others, DES is
considered weak.
.It Li clockskew = Va time
Maximum time differential (in seconds) allowed when comparing
times.
Default is 300 seconds (five minutes).
.It Li kdc_timeout = Va time
Maximum time to wait for a reply from the kdc, default is 3 seconds.
.It Li capath = {
.Bl -tag -width "xxx" -offset indent
.It Va destination-realm Li = Va next-hop-realm
.It ...
.It Li }
.El
This is deprecated, see the
.Li capaths
section below.
.It Li default_cc_type = Va cctype
sets the default credentials type.
.It Li default_cc_name = Va ccname
the default credentials cache name.
If you want to change the type only use
.Li default_cc_type .
The string can contain variables that are expanded at runtime. See the TOKEN
EXPANSION section.
.It Li default_file_cache_collections = Va FILE:/path/with/tokens ...
This multi-valued parameter allows more than one path to be
configured for the FILE credentials cache type to look in.  The FILE
credentials cache type will also consider file names whose prefixes
match these and end in
.Va +name
as subsidiary caches in the collection.  The values of this
parameter are subject to token expansion.  See the TOKEN EXPANSION
section.
.It Li enable_file_cache_iteration = Va boolean
If enabled, the
.Va FILE
credential cache type will support iteration of all subsidiary
caches in the default collection, meaning that
.Xr kinit 1
.Va -l
option will list them.  This does require scanning the directory
containing a given
.Va FILE
ccache, which, if it is
.Va /tmp
may be a slow operation.  Defaults to false.
.It Li default_etypes = Va etypes ...
A list of default encryption types to use. (Default: all enctypes if
allow_weak_crypto = TRUE, else all enctypes except single DES enctypes.)
.It Li default_as_etypes = Va etypes ...
A list of default encryption types to use in AS requests.  (Default: the
value of default_etypes.)
.It Li default_tgs_etypes = Va etypes ...
A list of default encryption types to use in TGS requests.  (Default:
the value of default_etypes.)
.It Li default_etypes_des = Va etypes ...
A list of default encryption types to use when requesting a DES credential.
.It Li default_keytab_name = Va keytab
The keytab to use if no other is specified, default is
.Dq FILE:/etc/krb5.keytab .
.It Li default_client_keytab_name = Va keytab
The keytab to use for client credential acquisition if no other is
specified, default is
.Dq FILE:%{LOCALSTATEDIR}/user/%{euid}/client.keytab .
See the TOKEN EXPANSION section.
.It Li dns_lookup_kdc = Va boolean
Use DNS SRV records to lookup KDC services location.
.It Li dns_lookup_realm = Va boolean
Use DNS TXT records to lookup domain to realm mappings.
.It Li enforce_ok_as_delegate = Va boolean
If this flag to true, GSSAPI credential delegation will be
disabled when the 
.Ar ok-as-delegate
flag is not set in the service ticket.
If this flag is false, the 
.Ar ok-as-delegate
ticket flag is only enforced when an application specifically
requests enforcement.
The default value is false.
.It Li kdc_timesync = Va boolean
Try to keep track of the time differential between the local machine
and the KDC, and then compensate for that when issuing requests.
.It Li max_retries = Va number
The max number of times to try to contact each KDC.
.It Li large_msg_size = Va number
The threshold where protocols with tiny maximum message sizes are not
considered usable to send messages to the KDC.
.It Li ticket_lifetime = Va time
Default ticket lifetime.
.It Li renew_lifetime = Va time
Default renewable ticket lifetime.
.It Li forwardable = Va boolean
When obtaining initial credentials, make the credentials forwardable.
This option is also valid in the [realms] section.
.It Li proxiable = Va boolean
When obtaining initial credentials, make the credentials proxiable.
This option is also valid in the [realms] section.
.It Li verify_ap_req_nofail = Va boolean
If enabled, failure to verify credentials against a local key is a
fatal error.
The application has to be able to read the corresponding service key
for this to work.
Some applications, like
.Xr su 1 ,
enable this option unconditionally.
.It Li warn_pwexpire = Va time
How soon to warn for expiring password.
Default is seven days.
.It Li http_proxy = Va proxy-spec
A HTTP-proxy to use when talking to the KDC via HTTP.
.It Li dns_proxy = Va proxy-spec
Enable using DNS via HTTP.
.It Li extra_addresses = Va address ...
A list of addresses to get tickets for along with all local addresses.
.It Li time_format = Va string
How to print time strings in logs, this string is passed to
.Xr strftime 3 .
.It Li date_format = Va string
How to print date strings in logs, this string is passed to
.Xr strftime 3 .
.It Li log_utc = Va boolean
Write log-entries using UTC instead of your local time zone.
.It Li scan_interfaces = Va boolean
Scan all network interfaces for addresses, as opposed to simply using
the address associated with the system's host name.
.It Li fcache_version = Va int
Use file credential cache format version specified.
.It Li fcc-mit-ticketflags = Va boolean
Use MIT compatible format for file credential cache.
It's the field ticketflags that is stored in reverse bit order for
older than Heimdal 0.7.
Setting this flag to
.Dv TRUE
makes it store the MIT way, this is default for Heimdal 0.7.
.It Li check-rd-req-server
If set to "ignore", the framework will ignore any of the server input to
.Xr krb5_rd_req 3 ,
this is very useful when the GSS-API server input the
wrong server name into the gss_accept_sec_context call.
.It Li k5login_directory = Va directory
Alternative location for user .k5login files. This option is provided
for compatibility with MIT krb5 configuration files. This path is
subject to percent token expansion (see TOKEN EXPANSION).
.It Li k5login_authoritative = Va boolean
If true then if a principal is not found in k5login files then
.Xr krb5_userok 3
will not fallback on principal to username mapping. This option is
provided for compatibility with MIT krb5 configuration files.
.It Li kuserok = Va rule ...
Specifies
.Xr krb5_userok 3
behavior.  If multiple values are given, then
.Xr krb5_userok 3
will evaluate them in order until one succeeds or all fail.  Rules are
implemented by plugins, with three built-in plugins
described below. Default: USER-K5LOGIN SIMPLE DENY.
.It Li kuserok = Va DENY
If set and evaluated then
.Xr krb5_userok 3
will deny access to the given username no matter what the principal name
might be.
.It Li kuserok = Va SIMPLE
If set and evaluated then
.Xr krb5_userok 3
will use principal to username mapping (see auth_to_local below).  If
the principal maps to the requested username then access is allowed.
.It Li kuserok = Va SYSTEM-K5LOGIN[:directory]
If set and evaluated then
.Xr krb5_userok 3
will use k5login files named after the
.Va luser
argument to
.Xr krb5_userok 3
in the given directory or in
.Pa /etc/k5login.d/ .
K5login files are text files, with each line containing just a principal
name; principals apearing in a user's k5login file are permitted access
to the user's account. Note: this rule performs no ownership nor
permissions checks on k5login files; proper ownership and
permissions/ACLs are expected due to the k5login location being a
system location.
.It Li kuserok = Va USER-K5LOGIN
If set and evaluated then
.Xr krb5_userok 3
will use
.Pa ~luser/.k5login
and
.Pa ~luser/.k5login.d/* .
User k5login files and directories must be owned by the user and must
not have world nor group write permissions.
.It Li aname2lname-text-db = Va filename
The named file must be a sorted (in increasing order) text file where
every line consists of an unparsed principal name optionally followed by
whitespace and a username.  The aname2lname function will do a binary
search on this file, if configured, looking for lines that match the
given principal name, and if found the given username will be used, or,
if the username is missing, an error will be returned.  If the file
doesn't exist, or if no matching line is found then other plugins will
be allowed to run.
.It Li fcache_strict_checking
strict checking in FILE credential caches that owner, no symlink and
permissions is correct.
.It Li moduli = Va FILE
Names a file that contains acceptable modular Diffie-Hellman
groups for PKINIT.
The given file should contain lines with whitespace-separated
fields in this order:
.Va name, nbits, p, g, q .
Lines starting with a
.Va #
are comments.
.It Li pkinit_dh_min_bits = Va NUMBER
PKINIT client's minimum acceptable modular Diffie-Hellman public
key size in bits.
.It Li enable-kx509 = Va boolean
Enable use of kx509 so that every TGT that can has a corresponding
PKIX certificate.  Default: false.
.It Li kx509_gen_key_type = Va public-key-type
Type of public key for kx509 private key generation.  Defaults to
.Va rsa
and currently only
.Va rsa
is supported.
.It Li kx509_gen_rsa_key_size = Va number-of-bits
RSA key size for kx509.  Defaults to 2048.
.It Li kx509_store = path
A file path into which to write a certificate obtained with
kx509, and its private key, when attempting kx509 optimistically
using credentials from a default ccache.  Tokens will be
expanded.
.It Li kx509_hostname = Va hostname
If set, then the kx509 client will use this hostname for the
kx509 service.  This can also be set in the
.Li [realm]
section on a per-realm basis.  If not set then a TGS name will be
used.
.It Li name_canon_rules = Va rules
One or more service principal name canonicalization rules.  Each rule
consists of one or more tokens separated by colon (':').  Currently
these rules are used only for hostname canonicalization (usually when
getting a service ticket, from a ccache or a TGS, but also when
acquiring GSS initiator credentials from a keytab).  These rules can be
used to implement DNS resolver-like search lists without having to use
DNS.
.Pp
NOTE: Name canonicalization rules are an experimental feature.
.Pp
The first token is a rule type, one of:
.Va as-is,
.Va qualify, or
.Va nss.
.Pp
Any remaining tokens must be options tokens:
.Va use_fast
(use FAST to protect TGS exchanges; currently not supported),
.Va use_dnssec
(use DNSSEC to protect hostname lookups; currently not supported),
.Va ccache_only
,
.Va use_referrals,
.Va no_referrals,
.Va lookup_realm,
.Va mindots=N,
.Va maxdots=N,
.Va order=N,
domain=
.Va domain,
realm=
.Va realm,
match_domain=
.Va domain,
and match_realm=
.Va realm.
.Pp
When trying to obtain a service ticket for a host-based service
principal name, name canonicalization rules are applied to that name in
the order given, one by one, until one succeds (a service ticket is
obtained), or all fail.  Similarly when acquiring GSS initiator
credentials from a keytab, and when comparing a non-canonical GSS name
to a canonical one.
.Pp
For each rule the system checks that the hostname has at least
.Va mindots
periods (if given) in it, at most
.Va maxdots
periods (if given), that the hostname ends in the given
.Va match_domain
(if given),
and that the realm of the principal matches the
.Va match_realm
(if given).
.Pp
.Va As-is
rules leave the hostname unmodified but may set a realm.
.Va Qualify
rules qualify the hostname with the given
.Va domain
and also may set the realm.
The
.Va nss
rule uses the system resolver to lookup the host's canonical name and is
usually not secure.  Note that using the
.Va nss
rule type implies having to have principal aliases in the HDB (though
not necessarily in keytabs).
.Pp
The empty realm denotes "ask the client's realm's TGS".  The empty realm
may be set as well as matched.
.Pp
The order in which rules are applied is as follows: first all the rules
with explicit
.Va order
then all other rules in the order in which they appear.  If any two
rules have the same explicit
.Va order ,
their order of appearance in krb5.conf breaks the tie.  Explicitly
specifying order can be useful where tools read and write the
configuration file without preserving parameter order.
.Pp
Malformed rules are ignored.
.It Li allow_hierarchical_capaths = Va boolean
When validating cross-realm transit paths, absent any explicit capath from the
client realm to the server realm, allow a hierarchical transit path via the
common ancestor domain of the two realms.
Defaults to true.
Note, absent an explicit setting, hierarchical capaths are always used by
the KDC when generating a referral to a destination with which is no direct
trust.
.It Li client_aware_channel_bindings = Va boolean
If this flag is true, then all application protocol authentication
requests will be flagged to indicate that the application supports
channel bindings when operating over a secure channel.
The default value is false.
.It Li check_pac = Va boolean
If this flag is true and a Windows Privilege Attribute Certificate (PAC)
is present in the ticket authorization data, then
.Xr krb5_rd_req 3
will validate the PAC before returning success. The default value is true.
.It Li report_canonical_client_name = Va boolean
If this flag is true, then the canonical client name from the PAC will
be used instead of the client name in the ticket. The default value is false.
Note that setting it to true implicitly sets
.Va check_pac
to true.
.El
.It Li [domain_realm]
This is a list of mappings from DNS domain to Kerberos realm.
.Pp
It is used by the client and the TGS both to determine the realm
of host-based service principal names based on the principal's
hostname component.
.Pp
The client may try DNS to determine a host's realm; see the
`dns_lookup_realm' parameter, and see below.
.Pp
The TGS will issue a referral when a host-based service does not
exist in the requested realm but can be mapped with these rules
to a different realm.
The TGS will also issue a referral when a host-based service
exists in the requested realm as an alias of a service in another
realm.
.Pp
Each binding in this section looks like:
.Pp
.Dl domain = realm
.Pp
The domain can be either a full name of a host or a trailing
component, in the latter case the domain-string should start with a
period.
The trailing component only matches hosts that are in the same domain, ie
.Dq .example.com
matches
.Dq foo.example.com ,
but not
.Dq foo.test.example.com .
.Pp
The realm may be the token `dns_locate', in which case the actual
realm will be determined using DNS (independently of the setting
of the `dns_lookup_realm' option).
.It Li [realms]
.Bl -tag -width "xxx" -offset indent
.It Va REALM Li = {
.Bl -tag -width "xxx" -offset indent
.It Li kdc = Va [service/]host[:port]
Specifies a list of kdcs for this realm.
If the optional
.Va port
is absent, the
default value for the
.Dq kerberos/udp
.Dq kerberos/tcp ,
and
.Dq http/tcp
port (depending on service) will be used.
The kdcs will be used in the order that they are specified.
.Pp
The optional
.Va service
specifies over what medium the kdc should be
contacted.
Possible services are
.Dq udp ,
.Dq tcp ,
and
.Dq http .
Http can also be written as
.Dq http:// .
Default service is
.Dq udp
and
.Dq tcp .
.It Li admin_server = Va host[:port]
Specifies the admin server for this realm, where all the modifications
to the database are performed.
.It Li kpasswd_server = Va host[:port]
Points to the server where all the password changes are performed.
If there is no such entry, the kpasswd port on the admin_server host
will be tried.
.It Li tgs_require_subkey
a boolan variable that defaults to false.
Old DCE secd (pre 1.1) might need this to be true.
.It Li auth_to_local_names = {
.Bl -tag -width "xxx" -offset indent
.It Va principal_name = Va username
The given
.Va principal_name
will be mapped to the given
.Va username
if the
.Va REALM
is a default realm.
.El
.It Li }
.It Li auth_to_local = HEIMDAL_DEFAULT
Use the Heimdal default principal to username mapping.
Applies to principals from the
.Va REALM
if and only if
.Va REALM
is a default realm.
.It Li auth_to_local = DEFAULT
Use the MIT default principal to username mapping.
Applies to principals from the
.Va REALM
if and only if
.Va REALM
is a default realm.
.It Li auth_to_local = DB:/path/to/db.txt
Use a binary search of the given DB.  The DB must be a flat-text
file sortedf in the "C" locale, with each record being a line
(separated by either LF or CRLF) consisting of a principal name
followed by whitespace followed by a username.
Applies to principals from the
.Va REALM
if and only if
.Va REALM
is a default realm.
.It Li auth_to_local = DB:/path/to/db
Use the given DB, if there's a plugin for it.
Applies to principals from the
.Va REALM
if and only if
.Va REALM
is a default realm.
.It Li auth_to_local = RULE:...
Use the given rule, if there's a plugin for it.
Applies to principals from the
.Va REALM
if and only if
.Va REALM
is a default realm.
.It Li auth_to_local = NONE
No additional principal to username mapping is done. Note that
.Va auth_to_local_names
and any preceding
.Va auth_to_local
rules have precedence.
.It Li pkinit_require_eku = BOOL
If
.Va true
then the KDC PKINIT Extended Key Usage (EKU) OID (1.3.6.5.2.3.5)
must be present in KDCs' PKINIT certificates.
Defaults to
.Va true .
.It Li pkinit_require_krbtgt_otherName = BOOL
If
.Va true
then the PKINIT Subject Alternative Name (SAN) for the TGS must
be present in KDCs' PKINIT certificates, and must match their
realm.
Defaults to
.Va true .
.It Li pkinit_require_hostname_match = BOOL
If
.Va true
then KDCs' PKINIT certificates must match their hostnames.
Defaults to
.Va false .
.It Li pkinit_trustedCertifiers = BOOL
If
.Va true
then PKINIT client will tell KDCs which trust anchors it trusts.
Defaults to
.Va true .
.It Li disable_pac = BOOL
If
.Va true
then the KDC will not sign tickets with PAC, which disables S4U2Proxy support.
Defaults to
.Va false .
.El
.It Li }
.El
.It Li [capaths]
.Bl -tag -width "xxx" -offset indent
.It Va client-realm Li = {
.Bl -tag -width "xxx" -offset indent
.It Va server-realm Li = Va hop-realm ...
This serves two purposes. First the first listed
.Va hop-realm
tells a client which realm it should contact in order to ultimately
obtain credentials for a service in the
.Va server-realm .
Secondly, it tells the KDC (and other servers) which realms are
allowed in a multi-hop traversal from
.Va client-realm
to
.Va server-realm .
Except for the client case, the order of the realms are not important.
.El
.It Va }
.El
.It Li [logging]
.Bl -tag -width "xxx" -offset indent
.It Va entity Li = Va destination
Specifies that
.Va entity
should use the specified
.Li destination
for logging.
See the
.Xr krb5_openlog 3
manual page for a list of defined destinations.
.El
.It Li [kdc]
.Bl -tag -width "xxx" -offset indent
.It Li database Li = {
.Bl -tag -width "xxx" -offset indent
.It Li dbname Li = Va [DATBASETYPE:]DATABASENAME
Use this database for this realm.  The
.Va DATABASETYPE
should be one of 'lmdb', 'db3', 'db1', 'db', 'sqlite', or 'ldap'.
See the info documetation how to configure different database backends.
.It Li realm Li = Va REALM
Specifies the realm that will be stored in this database.
It realm isn't set, it will used as the default database, there can
only be one entry that doesn't have a
.Li realm
stanza.
.It Li mkey_file Li = Pa FILENAME
Use this keytab file for the master key of this database.
If not specified
.Va DATABASENAME Ns .mkey
will be used.
.It Li acl_file Li = PA FILENAME
Use this file for the ACL list of this database.
.It Li log_file Li = Pa FILENAME
Use this file as the log of changes performed to the database.
This file is used by
.Nm ipropd-master
for propagating changes to slaves.  It is also used by
.Nm kadmind
and
.Nm kadmin
(when used with the
.Li -l
option), and by all applications using
.Nm libkadm5
with the local backend, for two-phase commit functionality.  Slaves also
use this.  Setting this to
.Nm /dev/null
disables two-phase commit and incremental propagation.  Use
.Nm iprop-log
to show the contents of this log file.
.It Li log-max-size = Pa number
When the log reaches this size (in bytes), the log will be truncated,
saving some entries, and keeping the latest version number so as to not
disrupt incremental propagation.  If set to a negative value then
automatic log truncation will be disabled.  Defaults to 52428800 (50MB).
.El
.It Li }
.It Li max-request = Va SIZE
Maximum size of a kdc request.
.It Li require-preauth = Va BOOL
If set pre-authentication is required.
.It Li ports = Va "list of ports"
List of ports the kdc should listen to.
.It Li addresses = Va "list of interfaces"
List of addresses the kdc should bind to.
.It Li enable-http = Va BOOL
Should the kdc answer kdc-requests over http.
.It Li tgt-use-strongest-session-key = Va BOOL
If this is TRUE then the KDC will prefer the strongest key from the
client's AS-REQ or TGS-REQ enctype list for the ticket session key that
is supported by the KDC and the target principal when the target
principal is a krbtgt principal.  Else it will prefer the first key from
the client's AS-REQ enctype list that is also supported by the KDC and
the target principal.  Defaults to FALSE.
.It Li svc-use-strongest-session-key = Va BOOL
Like tgt-use-strongest-session-key, but applies to the session key
enctype of tickets for services other than krbtgt principals. Defaults
to FALSE.
.It Li preauth-use-strongest-session-key = Va BOOL
If TRUE then select the strongest possible enctype from the client's
AS-REQ for PA-ETYPE-INFO2 (i.e., for password-based pre-authentication).
Else pick the first supported enctype from the client's AS-REQ.  Defaults
to FALSE.
.It Li use-strongest-server-key = Va BOOL
If TRUE then the KDC picks, for the ticket encrypted part's key, the
first supported enctype from the target service principal's hdb entry's
current keyset. Else the KDC picks the first supported enctype from the
target service principal's hdb entry's current keyset.  Defaults to TRUE.
.It Li check-ticket-addresses = Va BOOL
Verify the addresses in the tickets used in tgs requests.
.\" XXX
.It Li warn_ticket_addresses = Va BOOL
Warn about, but allow, usage of tickets from hosts that don't match the
addresses in the tickets.
.It Li allow-null-ticket-addresses = Va BOOL
Allow address-less tickets.
.\" XXX
.It Li disable_pac = Va BOOL
Do not include a PAC in service tickets.
However, if a service has the
.Li auth-data-reqd
attribute then the KDC will include a PAC anyways.
.It Li enable_fast = Va BOOL
Enable RFC 6113 FAST support, this is enabled by default.
.It Li enable_fast_cookie = Va BOOL
If FAST is enabled, enable support for the FAST cookie
and mechanisms that require it.
.It Li enable_armored_pa_enc_timestamp = Va BOOL
Enable armored encrypted timestamp pre-authentication with key
strengthening.
RFC 6113 says not to use PA-ENC-TIMESTAMP in FAST armored tunnels
as there is a newer replacement, PA-ENC-CHALLENGE, but for
interoperability with earlier versions of Heimdal, this is
enabled by default for now.
.It Li enable_unarmored_pa_enc_timestamp = Va BOOL
Enable unarmored encrypted timestamp pre-authentication.
Enabled by default for now, but in a future release will be
disabled.
.It Li enable-pkinit = Va BOOL
Enable PKINIT (disabled by default).
.It Li require-pkinit-freshness = Va BOOL
If PKINIT is enabled, require that PKINIT requests contain a
freshness token proving recent possession of the private key.
Disabled by default.
.It Li allow-anonymous = Va BOOL
If the kdc is allowed to hand out anonymous tickets.
.It Li synthetic_clients = Va BOOL
If enabled then the KDC will issue tickets for clients that don't
exist in the HDB provided that they use PKINIT, that PKINIT is
enabled, and that the client's have certificates with PKINIT
subject alternative names (SANs).
.It Li synthetic_clients_max_life = Va TIME
Maximum ticket lifetime for synthetic clients.
Default: 5 minutes.
.It Li synthetic_clients_max_renew = Va TIME
Maximum ticket renewable lifetime for synthetic clients.
Default: 5 minutes.
.It Li pkinit_identity = Va HX509-STORE
This is an HX509 store containing the KDC's PKINIT credential
(private key and end-entity certificate).
This is single valued, though multiple stores can be specified by
separating them with commas.
An
.Va HX509-STORE
is of the form
.Va TYPE:name
where
.Va TYPE
is one of
.Va FILE, Va PEM-FILE, Va DER-FILE, Va PKCS12, Va PKCS11,
or on OX X,
.Va KEYCHAIN .
The form of the
.Va name
depends on the
.Va TYPE .
For
.Va FILE, Va PEM-FILE, Va DER-FILE,
and
.Va PKCS12
the
.Va name
is a file path.
See the Heimdal hx509 documentation for more information.
.It Li pkinit_pool = Va HX509-STORE
This is a multi-valued parameter naming one or more stores of
intermediate certification authority (CA) certificates for the
KDC's end entity certificate.
.It Li pkinit_anchors = Va HX509-STORE ...
This is a multi-valued parameter naming one or more stores of
anchors for PKINIT client certificates.
Note that the
.Va DIR
type of
.Va HX509-STORE
is also supported here.
.Va DIR
type stores are OpenSSL-style CA certificate hash directories.
.It Li pkinit_revoke = Va HX509-STORE ...
This is a multi-valued parameter naming one or more stores of
CRLs for the issuers of PKINIT client certificates.
Only the first valid CRL for a particular issuer will be checked.
If no CRLs are configured, then CRLs will not be checked.
This is because the KDC will not dereference CRL distribution
points nor request OCSP responses.
.It Li pkinit_kdc_ocsp = Va PATH
This names a file whose contents is the DER encoding of an
OCSPResponse for the KDC's end entity certificate.
.It Li pkinit_kdc_friendly_name = Va NAME
This is an optional friendly name of the KDC's end entity
certificate.
This is only helpful when the
.Li pkinit_identity
store contains many credentials.
.It Li pkinit_principal_in_certificate = Va BOOL
If set to
.Va true
then the KDC will match AS-REQ client principal names to the
PKINIT
.Va subjectAlternativeName
values from the clients' certificates.
Defaults to
.Va true .
.It Li pkinit_dh_min_bits = Va NUMBER
Minimum acceptable modular Diffie-Hellman public key size in
bits.
.It Li pkinit_max_life_from_cert_extension = Va BOOL
If set to
.Va true
then the KDC will override the
.Va max_life
attribute of the client principal's HDB record with a maximum
ticket life taken from a certificate extension with OID
.Va { iso(1) member-body(2) se(752) su(43) heim-pkix(16) 4 }
and the DER encoding of an
.Va INTEGER
number of seconds.
Alternatively, if the extended key usage OID
.Va { iso(1) member-body(2) se(752) su(43) heim-pkix(16) 3 }
is included in the client's certificate, then the
.Va notAfter
minus the current time will be used.
.It Li pkinit_max_life_bound = Va TIME
If set, this will be a hard bound on the maximum ticket lifetime
taken from the client's certificate.
As usual,
.Va TIME
can be given as a number followed by a unit, such as
.Dq 2d
for
.Dq two days .
.It Li pkinit_max_life_from_cert = Va TIME
If set, this will override the
.Va max_life
attribute of the client principal's HDB record with the
.Va notAfter
of the client's certificate minus the current time, bounded to
the given relative
.Va TIME
unless the
.Li pkinit_max_life_from_cert_extension
parameter is set and the client's certificate has that extension.
As usual,
.Va TIME
can be given as a number followed by a unit, such as
.Dq 2d
for
.Dq two days .
.It Li enable_gss_preauth = Va boolean
Enables pre-authentication using a GSS-API mechanism supported by the client and KDC.
The GSS-API initiator and AS request client names must match, unless the
.Li WELLKNOWN/FEDERATED
name was used in the AS request, in which case the AS reply will contain the
GSS-API initiator name. Authorization and mapping behavior may be customized
by plugins. If synthetic clients are enabled, then the GSS-API initiator need
not exist in the local database. GSS-API pre-authentication is disabled by
default.
.It Li enable_gss_auth_data = Va boolean
When using GSS-API pre-authentication, includes a Kerberos authorization data
element containing naming attributes associated with the GSS-API initiator. This
is disabled by default as it may significantly increase the size of returned
tickets.
.It Li gss_mechanisms_allowed = Va mechs ...
A list of GSS-API mechanisms that may be used for GSS-API pre-authentication.
.It Li gss_cross_realm_mechanisms_allowed = Va mechs ...
A list of GSS-API mechanisms that, when using the default authorization
mechanism, will be permitted to map Kerberos principals in foreign realms. The
list is empty by default. Initiator names from mechanisms not on this list will
be mapped to an enterprise principal in the AS-REQ realm. This option is
intended to avoid conflating GSS-API pre-authentication and Kerberos
cross-realm authentication. The behavior is provided by the default
authorization mechanism and will be overridden by an authorization plugin.
Mechanisms may be identified by dot-separated OID or a short name.
.It Li historical_anon_realm = Va boolean
Enables pre-7.0 non-RFC-comformant KDC behavior.
With this option set to
.Li true
the client realm in anonymous pkinit AS replies will be the requested realm,
rather than the RFC-conformant
.Li WELLKNOWN:ANONYMOUS
realm.
This can have a security impact on servers that expect to grant access to
anonymous-but-authenticated to the KDC users of the realm in question:
they would also grant access to unauthenticated anonymous users.
As such, it is not recommend to set this option to
.Li true.
.It Li encode_as_rep_as_tgs_rep = Va BOOL
Encode as-rep as tgs-rep to be compatible with mistakes older DCE secd did.
.\" XXX
.It Li kdc_warn_pwexpire = Va TIME
The time before expiration that the user should be warned that her
password is about to expire.
.It Li logging = Va Logging
What type of logging the kdc should use, see also [logging]/kdc.
.It Li hdb-ldap-structural-object Va structural object
If the LDAP backend is used for storing principals, this is the
structural object that will be used when creating and when reading
objects.
The default value is account .
.It Li hdb-ldap-create-base Va creation dn
is the dn that will be appended to the principal when creating entries.
Default value is the search dn.
.It Li enable-digest = Va BOOL
Should the kdc answer digest requests. The default is FALSE.
.It Li digests_allowed = Va list of digests
Specifies the digests the kdc will reply to. The default is
.Li ntlm-v2 .
.It Li enable-kx509 = Va boolean
Enables kx509 service.
.Pp
The kx509 service is configurable for a number of cases:
.Bl -tag -width "" -offset indent
.It Li default certificates for user or service principals,
.It Li non-default certificate requests including subject alternative names (SAN) and extended key usage (EKU) certificate extensions, for either client, server, or mixed usage.
.El
.Pp
Distinct configurations are supported for all of these cases as
shown below:
.Bd -literal -offset indent
[kdc]
    enable-kx509 = yes | no
    require_csr  = yes | no
    require_initial_kca_tickets = yes | no
    realm = {
        <REALM> = {
            kx509 = {
                <label> = {
                    <param> = <value>
                }
                hostbased_service = {
                    <service> = {
                        <param> = <value>
                    }
                }
            }
        }
    }
.Ed
where
.Va label
is one of:
.Bl -tag -width "xxx" -offset indent
.It Li user
for default certificates for user principals,
.It Li root_user
for default certificates for root user principals,
.It Li admin_user
for default certificates for admin user principals,
.It Li hostbased_service
for default certificates for host-based service principals, in which case the
service name is used as shown above,
.It Li client
for non-default client certificates,
.It Li server
for non-default server certificates,
.It Li mixed
for non-default client and server certificates.
.El
and where the parameters are as follows:
.Bl -tag -width "xxx" -offset indent
.It Li ca = Va file
Specifies the PEM credentials for the kx509 / bx509d certification
authority.
If not specified for any specific use-case, then that use-case
will be disabled.
.It Li max_cert_lifetime = Va NUMunit
Specifies the maximum certificate lifetime as a decimal number
and an optional unit (the default unit is
.Dq day
).
.It Li force_cert_lifetime = Va NUMunit
Specifies a minimum certificate lifetime as a decimal number and
an optional unit (the default unit is
.Dq day
).
.It Li allow_extra_lifetime = Va boolean
Indicates whether a client may request longer lifetimes than
their authentication credentials.
Defaults to false.
.It Li require_initial_kca_tickets = Va boolean
Specified whether to require that tickets for the
.Li kca_service
service principal be INITIAL.
This may be set on a per-realm basis as well as globally.
Defaults to true for the global setting.
.It Li include_pkinit_san = Va boolean
If true then the kx509 client principal's name and realm will be
included in an
.Li id-pkinit-san
subject alternative name certificate extension.
This can be set on a per-realm basis as well as globally.
Defaults to true for the global setting.
.It Li email_domain = Va domain
If set then the kx509 client user principal's name at the given
domain will be included in an
.Li rfc822Name
subject alternative name certificate extension.
This can be set on a per-realm basis as well as globally.
Defaults to false for the global setting.
.It Li include_dnsname_san = Va boolean
If true then a kx509 host-based or domain-based client
principal's hostname will be included in an
.Li dNSName
subject alternative name certificate extension, with the
downcased realm as the domainname.  This can be set on a
per-realm basis as well as
globally.  Defaults to false for the global setting.
.It Li ekus = Va OID
List of OIDs to include as EKUs.
.It Li subject_name = Va DN
Specifies a subject name that should either be empty or contain
variable interpolation as described below for
.Va template_cert .
The subject may be the empty string, causing the issued
certificates' subject names to be empty.
.It Li template_cert = Va store
Specifies the hx509 store (e.g.,
.Va PEM-FILE:path )
with a template
for the certificates to be issued to kx509 clients whose
principal names have one component (i.e., are user principals).
A template is a certificate with variables to be interpolated in
the subjectName.  The following variables can be interpolated in
the subject name using
.Va ${variable}
syntax:
.Bl -tag -width "xxx" -offset indent
.It principal-name
The full name of the kx509 client principal.
.It principal-name-without-realm
The full name of the kx509 client principal, excluding the realm name.
.It principal-name-realm
The name of the client principal's realm.
.It principal-component0
The first component of the client principal.
.It principal-component1
The second component of the client principal.
.It principal-component2
The third component of the client principal.
.It principal-service-name
The name of the service.
.It principal-host-name
The name of the host.
.El
.Pp
If a template and subject name are not specified and no default
SANs are configured, then no certificate will be issued.
Otherwise if a template and subject name are not specified, then
subject of the certificate will be empty.
.El
.El
.Pp
.It Li [hdb]
.Bl -tag -width "xxx" -offset indent
.It Li db-dir = Va path
This parameter defines a directory that can contain:
.Bl -tag -width "xxx" -offset indent
.It Va kdc.conf
A configuration file with the same format as krb5.conf that will
be included.
.It Va m-key
The master key file.
.It Va kdc.log
The default logfile for the KDC when a logfile is not specified in
.Li [logging]
.It Va kadm5.acl
The access controls for
.Nm kadmind .
.It Va log
The (binary) log of transactions used for
.Nm HDB
replication via the
.Nm iprop
protocol.
See
.Nm iprop-log(1)
for more detail.
.It Va pki-mapping
The default PKINIT mapping file if one is not specified in
.Va [kdc] pkinit_mappings_file .
.El
and other files related to
.Nm iprop
operation.
.It Li new_service_key_delay = Va time
Sets a bias such that new keys are not taken into service until
after the given time has passed since they were set.
This is useful for key rotation on concrete principals shared by
multiple instances of an application: set this time to twice or
more the keytab fetch period used by applications.
.It Li enable_virtual_hostbased_princs = Va boolean
Heimdal supports a notion of virtual host-based service
principals whose keys are derived from those of a base namespace
principal of the form
.Nm WELLKNOWN/HOSTBASED-NAMESPACE/svc/hostname .
The service name can be wild-carded as
.Va _ .
Non-wildcarded services have to be listed in the
.Li virtual_hostbased_princ_svcs
parameter (see below).
This parameter enables this feature, which is disabled by
default.
.It Li virtual_hostbased_princ_ndots = Va Integer
Minimum number of label-separating periods in virtual host-based
service principals' hostname component.
.It Li virtual_hostbased_princ_maxdots = Va Integer
Maximum number of label-separating periods in namespaces'
hostname component.
.It Li virtual_hostbased_princ_svcs = Va service-name
This multi-valued parameter lists service names not to wildcard
when searching for a namespace for a virtual host-based service
principal.
Other service names will have keys derived from a matching
namespace with a wild-carded service name.
This allows one to have different attributes for different
services.
For example, the
.Nm "host"
service can be configured to have the ok-as-delegate flag while
all others do not.
.El
.Pp
.It Li [bx509]
This section contains online certification authority configuration, much
like
.Li kx509
in the
.Li [kdc]
section, but with the
.Li kx509
layer removed.
.Bd -literal -offset indent
[kdc]
    realm = {
        <REALM> = {
            ...
        }
    }
.Ed
.It Li [get-tgt]
.Bl -tag -width "xxx" -offset indent
.It Li no_addresses = Va BOOL
If set to
.Va true
then the
.Va /get-tgt
end-point of the
.Xr bx509d 8
service will issue address-less TGTs.
If set to
.Va false
then the
.Va /get-tgt
end-point of the
.Xr bx509d 8
service will include the client's IP address in the TGT it issues
it.
Defaults to
.Va true .
.It Li allow_addresses = Va BOOL
If set to
.Va true
then the
.Va /get-tgt
end-point of the
.Xr bx509d 8
service will add arbitrary addresses requested by clients to the
TGTs it issues them.
Defaults to
.Va false .
.El
.Pp
Certification authority related parameters are as for
.Va bx509 .
.It Li [kadmin]
.Bl -tag -width "xxx" -offset indent
.It Li password_lifetime = Va time
If a principal already have its password set for expiration, this is
the time it will be valid for after a change. A value of 0 will clear
the password expiration after a successful password change.
.It Li default_keys = Va keytypes...
For each entry in
.Va default_keys
try to parse it as a sequence of
.Va etype:salttype:salt
syntax of this if something like:
.Pp
[(des|des3|etype):](pw-salt|afs3-salt)[:string]
.Pp
If
.Ar etype
is omitted it means everything, and if string is omitted it means the
default salt string (for that principal and encryption type).
Additional special values of keytypes are:
.Bl -tag -width "xxx" -offset indent
.It Li v5
The Kerberos 5 salt
.Va pw-salt
.El
.It Li default_key_rules = Va {
.Bl -tag -width "xxx" -offset indent
.It Va globing-rule Li = Va keytypes...
a globbing rule to matching a principal, and when true, use the
keytypes as specified the same format as [kadmin]default_keys .
.El
.It Li }
.It Li prune-key-history = Va BOOL
When adding keys to the key history, drop keys that are too old to match
unexpired tickets (based on the principal's maximum ticket lifetime).
If the KDC keystore is later compromised traffic protected with the
discarded older keys may remain protected.  This also keeps the HDB
records for principals with key history from growing without bound.
The default (backwards compatible) value is "false".
.It Li use_v4_salt = Va BOOL
When true, this is the same as
.Pp
.Va default_keys = Va des3:pw-salt Va v4
.Pp
and is only left for backwards compatibility.
.It Li [password_quality]
Check the Password quality assurance in the info documentation for
more information.
.Bl -tag -width "xxx" -offset indent
.It Li check_library = Va library-name
Library name that contains the password check_function
.It Li check_function = Va function-name
Function name for checking passwords in check_library
.It Li policy_libraries = Va library1 ... libraryN
List of libraries that can do password policy checks
.It Li policies = Va policy1 ... policyN
List of policy names to apply to the password. Builtin policies are
among other minimum-length, character-class, external-check.
.El
.El
.El
.Sh TOKEN EXPANSION
The values of some parameters are subject to percent token expansion.
Expansions supported on all platforms:
.Bl -tag -width "xxx" -offset indent
.It %{LIBDIR}
The install location of Heimdal libraries.
.It %{BINDIR}
The install location of Heimdal user programs.
.It %{LIBEXEC}
The install location of Heimdal services.
.It %{SBINDIR}
The install location of Heimdal admin programs.
.It %{username}
The current username.
.It %{TEMP}
A temporary directory.
.It %{USERID}
The current user's SID (Windows) or effective user ID (POSIX).
.It %{uid}
The current user's SID (Windows) or real user ID (POSIX).  On POSIX it is best
to use the
.Va %{euid}
token instead (see below).
.It %{null}
The empty string.
.El
.Pp
Expansions supported on POSIX-like platforms:
.Bl -tag -width "xxx" -offset indent
.It %{euid}
The current effective user ID.
.It %{loginname}
The username of the logged-in user for this terminal.
.It %{LOCALSTATEDIR}
The install location of Heimdal databases.
.El
.Pp
On Windows, several additional tokens can also be expanded:
.Bl -tag -width "xxx" -offset indent
.It %{APPDATA}
Roaming application data (for current user).
.It %{COMMON_APPDATA}
Application data (all users).
.It %{LOCAL_APPDATA}
Local application data (for current user).
.It %{SYSTEM}
Windows System folder.
.It %{WINDOWS}
Windows folder.
.It %{USERCONFIG}
Per user Heimdal configuration file path.
.It %{COMMONCONFIG}
Common Heimdal configuration file path.
.El
.Sh ENVIRONMENT
.Ev KRB5_CONFIG
points to the configuration file to read.
.Sh FILES
.Bl -tag -width "/etc/krb5.conf"
.It Pa /etc/krb5.conf
configuration file for Kerberos 5.
.El
.Sh EXAMPLES
.Bd -literal -offset indent
[libdefaults]
	default_realm = FOO.SE
	name_canon_rules = as-is:realm=FOO.SE
	name_canon_rules = qualify:domain=foo.se:realm=FOO.SE
	name_canon_rules = qualify:domain=bar.se:realm=FOO.SE
	name_canon_rules = nss
[domain_realm]
	.foo.se = FOO.SE
	.bar.se = FOO.SE
[realms]
	FOO.SE = {
		kdc = kerberos.foo.se
		default_domain = foo.se
	}
[logging]
	kdc = FILE:/var/heimdal/kdc.log
	kdc = SYSLOG:INFO
	default = SYSLOG:INFO:USER
[kadmin]
	default_key_rules = {
		*/ppp@* = arcfour-hmac-md5:pw-salt
	}
.Ed
.Sh DIAGNOSTICS
Since
.Nm
is read and parsed by the krb5 library, there is not a lot of
opportunities for programs to report parsing errors in any useful
format.
To help overcome this problem, there is a program
.Nm verify_krb5_conf
that reads
.Nm
and tries to emit useful diagnostics from parsing errors.
Note that this program does not have any way of knowing what options
are actually used and thus cannot warn about unknown or misspelled
ones.
.Sh SEE ALSO
.Xr kinit 1 ,
.Xr krb5_openlog 3 ,
.Xr strftime 3 ,
.Xr verify_krb5_conf 8