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.Dd April 24, 2005
.Dt KRB5_SET_DEFAULT_REALM 3
.Os
.Sh NAME
.Nm krb5_copy_host_realm ,
.Nm krb5_free_host_realm ,
.Nm krb5_get_default_realm ,
.Nm krb5_get_default_realms ,
.Nm krb5_get_host_realm ,
.Nm krb5_set_default_realm
.Nd default and host realm read and manipulation routines
.Sh LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
.Sh SYNOPSIS
.In krb5/krb5.h
.Ft krb5_error_code
.Fo krb5_copy_host_realm
.Fa "krb5_context context"
.Fa "const krb5_realm *from"
.Fa "krb5_realm **to"
.Fc
.Ft krb5_error_code
.Fo krb5_free_host_realm
.Fa "krb5_context context"
.Fa "krb5_realm *realmlist"
.Fc
.Ft krb5_error_code
.Fo krb5_get_default_realm
.Fa "krb5_context context"
.Fa "krb5_realm *realm"
.Fc
.Ft krb5_error_code
.Fo krb5_get_default_realms
.Fa "krb5_context context"
.Fa "krb5_realm **realm"
.Fc
.Ft krb5_error_code
.Fo krb5_get_host_realm
.Fa "krb5_context context"
.Fa "const char *host"
.Fa "krb5_realm **realms"
.Fc
.Ft krb5_error_code
.Fo krb5_set_default_realm
.Fa "krb5_context context"
.Fa "const char *realm"
.Fc
.Sh DESCRIPTION
.Fn krb5_copy_host_realm
copies the list of realms from
.Fa from
to
.Fa to .
.Fa to
should be freed by the caller using
.Fa krb5_free_host_realm .
.Pp
.Fn krb5_free_host_realm
frees all memory allocated by
.Fa realmlist .
.Pp
.Fn krb5_get_default_realm
returns the first default realm for this host.
The realm returned should be freed with
.Fn krb5_xfree .
.Pp
.Fn krb5_get_default_realms
returns a
.Dv NULL
terminated list of default realms for this context.
Realms returned by
.Fn krb5_get_default_realms
should be freed with
.Fn krb5_free_host_realm .
.Pp
.Fn krb5_get_host_realm
returns a
.Dv NULL
terminated list of realms for
.Fa host
by looking up the information in the
.Li [domain_realm]
in
.Pa krb5.conf
or in
.Li DNS .
If the mapping in
.Li [domain_realm]
results in the string
.Li dns_locate ,
DNS is used to lookup the realm.
.Pp
When using
.Li DNS
to a resolve the domain for the host a.b.c,
.Fn krb5_get_host_realm
looks for a
.Dv TXT
resource record named
.Li _kerberos.a.b.c ,
and if not found, it strips off the first component and tries a again
(_kerberos.b.c) until it reaches the root.
.Pp
If there is no configuration or DNS information found,
.Fn krb5_get_host_realm
assumes it can use the domain part of the
.Fa host
to form a realm.
Caller must free
.Fa realmlist
with
.Fn krb5_free_host_realm .
.Pp
.Fn krb5_set_default_realm
sets the default realm for the
.Fa context .
If
.Dv NULL
is used as a
.Fa realm ,
the
.Li [libdefaults]default_realm
stanza in
.Pa krb5.conf
is used.
If there is no such stanza in the configuration file, the
.Fn krb5_get_host_realm
function is used to form a default realm.
.Sh SEE ALSO
.Xr free 3 ,
.Xr krb5.conf 5