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.Dd June 15, 2006
.Dt KRB5_GET_CREDS 3
.Os HEIMDAL
.Sh NAME
.Nm krb5_get_creds ,
.Nm krb5_get_creds_opt_add_options ,
.Nm krb5_get_creds_opt_alloc ,
.Nm krb5_get_creds_opt_free ,
.Nm krb5_get_creds_opt_set_enctype ,
.Nm krb5_get_creds_opt_set_impersonate ,
.Nm krb5_get_creds_opt_set_options ,
.Nm krb5_get_creds_opt_set_ticket
.Nd get credentials from the KDC
.Sh LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)
.Sh SYNOPSIS
.In krb5.h
.Ft krb5_error_code
.Fo krb5_get_creds
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "krb5_ccache ccache"
.Fa "krb5_const_principal inprinc"
.Fa "krb5_creds **out_creds"
.Fc
.Ft void
.Fo krb5_get_creds_opt_add_options
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "krb5_flags options"
.Fc
.Ft krb5_error_code
.Fo krb5_get_creds_opt_alloc
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt *opt"
.Fc
.Ft void
.Fo krb5_get_creds_opt_free
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fc
.Ft void
.Fo krb5_get_creds_opt_set_enctype
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "krb5_enctype enctype"
.Fc
.Ft krb5_error_code
.Fo krb5_get_creds_opt_set_impersonate
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "krb5_const_principal self"
.Fc
.Ft void
.Fo krb5_get_creds_opt_set_options
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "krb5_flags options"
.Fc
.Ft krb5_error_code
.Fo krb5_get_creds_opt_set_ticket
.Fa "krb5_context context"
.Fa "krb5_get_creds_opt opt"
.Fa "const Ticket *ticket"
.Fc
.Sh DESCRIPTION
.Fn krb5_get_creds
fetches credentials specified by
.Fa opt
by first looking in the
.Fa ccache ,
and then it doesn't exists, fetch the credential from the KDC
using the krbtgts in
.Fa ccache .
The credential is returned in
.Fa out_creds
and should be freed using the function
.Fn krb5_free_creds .
.Pp
The structure
.Li krb5_get_creds_opt
controls the behavior of
.Fn krb5_get_creds .
The structure is opaque to consumers that can set the content of the
structure with accessors functions. All accessor functions make copies
of the data that is passed into accessor functions, so external
consumers free the memory before calling
.Fn krb5_get_creds .
.Pp
The structure
.Li krb5_get_creds_opt
is allocated with
.Fn krb5_get_creds_opt_alloc
and freed with
.Fn krb5_get_creds_opt_free .
The free function also frees the content of the structure set by the
accessor functions.
.Pp
.Fn krb5_get_creds_opt_add_options
and
.Fn krb5_get_creds_opt_set_options
adds and sets options to the
.Fi krb5_get_creds_opt
structure .
The possible options to set are
.Bl -tag -width "KRB5_GC_USER_USER" -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 options 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.
.It KRB5_GC_NO_STORE
Do not store the resulting credentials in the
.Fa ccache .
.El
.Pp
.Fn krb5_get_creds_opt_set_enctype
sets the preferred encryption type of the application. Don't set this
unless you have to since if there is no match in the KDC, the function
call will fail.
.Pp
.Fn krb5_get_creds_opt_set_impersonate
sets the principal to impersonate., Returns a ticket that have the
impersonation principal as a client and the requestor as the
service. Note that the requested principal have to be the same as the
client principal in the krbtgt.
.Pp
.Fn krb5_get_creds_opt_set_ticket
sets the extra ticket used in user-to-user or contrained delegation use case.
.Sh SEE ALSO
.Xr krb5 3 ,
.Xr krb5_get_credentials 3 ,
.Xr krb5.conf 5