heimdal/lib/krb5/krb5_get_credentials.3

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.Dd July 26, 2004
.Dt KRB5_GET_CREDENTIALS 3
.Os HEIMDAL
.Sh NAME
.Nm krb5_get_credentials ,
.Nm krb5_get_credentials_with_flags ,
.Nm krb5_get_cred_from_kdc ,
.Nm krb5_get_cred_from_kdc_opt ,
.Nm krb5_get_kdc_cred ,
.Nm krb5_get_renewed_creds
.Nd get credentials from the KDC using krbtgt
.Sh LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
.Sh SYNOPSIS
.In krb5.h
.Ft krb5_error_code
.Fo krb5_get_credentials
.Fa "krb5_context context"
.Fa "krb5_flags options"
.Fa "krb5_ccache ccache"
.Fa "krb5_creds *in_creds"
.Fa "krb5_creds **out_creds"
.Fc
.Ft krb5_error_code
.Fo krb5_get_credentials_with_flags
.Fa "krb5_context context"
.Fa "krb5_flags options"
.Fa "krb5_kdc_flags flags"
.Fa "krb5_ccache ccache"
.Fa "krb5_creds *in_creds"
.Fa "krb5_creds **out_creds"
.Fc
.Ft krb5_error_code
.Fo krb5_get_cred_from_kdc
.Fa "krb5_context context"
.Fa "krb5_ccache ccache"
.Fa "krb5_creds *in_creds"
.Fa "krb5_creds **out_creds"
.Fa "krb5_creds ***ret_tgts"
.Fc
.Ft krb5_error_code
.Fo krb5_get_cred_from_kdc_opt
.Fa "krb5_context context"
.Fa "krb5_ccache ccache"
.Fa "krb5_creds *in_creds"
.Fa "krb5_creds **out_creds"
.Fa "krb5_creds ***ret_tgts"
.Fa "krb5_flags flags"
.Fc
.Ft krb5_error_code
.Fo krb5_get_kdc_cred
.Fa "krb5_context context"
.Fa "krb5_ccache id"
.Fa "krb5_kdc_flags flags"
.Fa "krb5_addresses *addresses"
.Fa "Ticket  *second_ticket"
.Fa "krb5_creds *in_creds"
.Fa "krb5_creds **out_creds"
.Fc
.Ft krb5_error_code
.Fo krb5_get_renewed_creds
.Fa "krb5_context context"
.Fa "krb5_creds *creds"
.Fa "krb5_const_principal client"
.Fa "krb5_ccache ccache"
.Fa "const char *in_tkt_service"
.Fc
.Sh DESCRIPTION
.Fn krb5_get_credentials_with_flags
get credentials specified by
.Fa in_creds->server
and
.Fa in_creds->client
(the rest of the
.Fa in_creds
structure is ignored)
by first looking in the
.Fa ccache
and if doesn't exists or is expired, fetch the credential from the KDC
using the krbtgt in
.Fa ccache .
The credential is returned in
.Fa out_creds
and should be freed using the function
.Fn krb5_free_creds .
.Pp
Valid flags to pass into
.Fa options
argument are:
.Pp
.Bl -tag -width "KRB5_GC_EXPIRED_OK" -compact
.It KRB5_GC_CACHED
Only check the
.Fa ccache ,
don't got out on network to fetch credential.
.It KRB5_GC_USER_USER
Request a user to user ticket.
This option doesn't store the resulting user to user credential in
the
.Fa ccache .
.It KRB5_GC_EXPIRED_OK
returns the credential even if it is expired, default behavior is trying
to refetch the credential from the KDC.
.El
.Pp
.Fa Flags
are KDCOptions, note the caller must fill in the bit-field and not
use the integer associated structure.
.Pp
.Fn krb5_get_credentials
works the same way as
.Fn krb5_get_credentials_with_flags
except that the
.Fa flags
field is missing.
.Pp
.Fn krb5_get_cred_from_kdc
and
.Fn krb5_get_cred_from_kdc_opt
fetches the credential from the KDC very much like
.Fn krb5_get_credentials ,
but doesn't look in the
.Fa ccache
if the credential exists there first.
.Pp
.Fn krb5_get_kdc_cred
does the same as the functions above, but the caller must fill in all
the information andits closer to the wire protocol.
.Pp
.Fn krb5_get_renewed_creds
renews a credential given by
.Fa in_tkt_service
(if
.Dv NULL
the default
.Li krbtgt )
using the credential cache
.Fa ccache .
The result is stored in
.Fa creds
and should be freed using
.Fa krb5_free_creds .
.Sh EXAMPLES
Here is a example function that get a credential from a credential cache
.Fa id
or the KDC and returns it to the caller.
.Bd -literal
#include <krb5.h>

int
getcred(krb5_context context, krb5_ccache id, krb5_creds **creds)
{
    krb5_error_code ret;
    krb5_creds in;

    ret = krb5_parse_name(context, "client@EXAMPLE.COM",
			  &in.client);
    if (ret)
	krb5_err(context, 1, ret, "krb5_parse_name");

    ret = krb5_parse_name(context, "host/server.example.com@EXAMPLE.COM",
			  &in.server);
    if (ret)
	krb5_err(context, 1, ret, "krb5_parse_name");

    ret = krb5_get_credentials(context, 0, id, &in, creds);
    if (ret)
	krb5_err(context, 1, ret, "krb5_get_credentials");

    return 0;
}
.Ed
.Sh SEE ALSO
.Xr krb5 3 ,
.Xr krb5_get_forwarded_creds 3 ,
.Xr krb5.conf 5