.\" Copyright (c) 2003 - 2006 Kungliga Tekniska Högskolan
.\" (Royal Institute of Technology, Stockholm, Sweden).
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\"
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" 3. Neither the name of the Institute nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $Id$
.\"
.Dd May  1, 2006
.Dt KRB5_VERIFY_INIT_CREDS 3
.Os HEIMDAL
.Sh NAME
.Nm krb5_verify_init_creds_opt_init ,
.Nm krb5_verify_init_creds_opt_set_ap_req_nofail ,
.Nm krb5_verify_init_creds
.Nd "verifies a credential cache is correct by using a local keytab"
.Sh LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
.Sh SYNOPSIS
.In krb5.h
.Pp
.Li "struct krb5_verify_init_creds_opt;"
.Ft void
.Fo krb5_verify_init_creds_opt_init
.Fa "krb5_verify_init_creds_opt *options"
.Fc
.Ft void
.Fo krb5_verify_init_creds_opt_set_ap_req_nofail
.Fa "krb5_verify_init_creds_opt *options"
.Fa "int ap_req_nofail"
.Fc
.Ft krb5_error_code
.Fo krb5_verify_init_creds
.Fa "krb5_context context"
.Fa "krb5_creds *creds"
.Fa "krb5_principal ap_req_server"
.Fa "krb5_ccache *ccache"
.Fa "krb5_verify_init_creds_opt *options"
.Fc
.Sh DESCRIPTION
The
.Nm krb5_verify_init_creds
function verifies the initial tickets with the local keytab to make
sure the response of the KDC was spoof-ed.
.Pp
.Nm krb5_verify_init_creds
will use principal
.Fa ap_req_server
from the local keytab, if
.Dv NULL
is passed in, the code will guess the local hostname and use that to
form host/hostname/GUESSED-REALM-FOR-HOSTNAME.
.Fa creds
is the credential that
.Nm krb5_verify_init_creds
should verify.
If
.Fa ccache
is given
.Fn krb5_verify_init_creds
stores all credentials it fetched from the KDC there, otherwise it
will use a memory credential cache that is destroyed when done.
.Pp
.Fn krb5_verify_init_creds_opt_init
cleans the the structure, must be used before trying to pass it in to
.Fn krb5_verify_init_creds .
.Pp
.Fn krb5_verify_init_creds_opt_set_ap_req_nofail
controls controls the behavior if
.Fa ap_req_server
doesn't exists in the local keytab or in the KDC's database, if it's
true, the error will be ignored.  Note that this use is possible
insecure.
.Sh SEE ALSO
.Xr krb5 3 ,
.Xr krb5_get_init_creds 3 ,
.Xr krb5_verify_user 3 ,
.Xr krb5.conf 5