.TH LDAP_BIND 3 "22 September 1998" "OpenLDAP LDVERSION"
.SH NAME
ldap_bind, ldap_bind_s, ldap_simple_bind, ldap_simple_bind_s, ldap_kerberos_bind_s, ldap_kerberos_bind1, ldap_kerberos_bind1_s, ldap_kerberos_bind2, ldap_kerberos_bind2_s, ldap_unbind, ldap_unbind_s, ldap_set_rebind_proc \- LDAP bind routines
.SH SYNOPSIS
.nf
.ft B
#include <lber.h>
#include <ldap.h>
.LP
.ft B
int ldap_bind(ld, who, cred, method)
.ft
LDAP *ld;
char *who, *cred;
int method;
.LP
.ft B
int ldap_bind_s(ld, who, cred, method)
.ft
LDAP *ld;
char *who, *cred;
int method;
.LP
.ft B
int ldap_simple_bind(ld, who, passwd)
.ft
LDAP *ld;
char *who, *passwd;
.LP
.ft B
int ldap_simple_bind_s(ld, who, passwd)
.ft
LDAP *ld;
char *who, *passwd;
.LP
.ft B
int ldap_kerberos_bind_s(ld, who)
.ft
LDAP *ld;
char *who;
.LP
.ft B
int ldap_kerberos_bind1(ld, who)
.ft
LDAP *ld;
char *who;
.LP
.ft B
int ldap_kerberos_bind1_s(ld, who)
.ft
LDAP *ld;
char *who;
.LP
.ft B
int ldap_kerberos_bind2(ld, who)
.ft
LDAP *ld;
char *who;
.LP
.ft B
int ldap_kerberos_bind2_s(ld, who)
.ft
LDAP *ld;
char *who;
.LP
.ft B
int ldap_unbind(ld)
.ft
LDAP *ld;
.LP
.ft B
int ldap_unbind_s(ld)
.ft
LDAP *ld;
.LP
.ft B
void ldap_set_rebind_proc( ld, rebindproc )
.ft
LDAP *ld;
int (*rebindproc)();
.SH DESCRIPTION
.LP
These routines provide various interfaces to the LDAP bind operation.
After a connection is made to an LDAP server using
.BR ldap_open (3),
an LDAP bind operation must be performed before other operations can
be attempted over the conection.  Both synchronous and asynchronous
versions of each variant of the bind call are provided.  There are
three types of calls, providing simple authentication, kerberos
authentication, and general routines to do either one.  All routines
take \fIld\fP as their first parameter, as returned from
.BR ldap_open (3).
.SH SIMPLE AUTHENTICATION
The simplest form of the bind call is
.BR ldap_simple_bind_s() .
It takes the DN to bind as in \fIwho\fP, and the userPassword associated
with the entry in \fIpasswd\fP.  It returns an LDAP error indication
(see
.BR ldap_error (3)).
The
.B ldap_simple_bind()
call is asynchronous,
taking the same parameters but only initiating the bind operation and
returning the message id of the request it sent.  The result of the
operation can be obtained by a subsequent call to
.BR ldap_result (3).
.SH KERBEROS AUTHENTICATION
If the LDAP library and LDAP server being contacted have been
compiled with the KERBEROS option defined,
Kerberos version 4 authentication can be accomplished by calling
the
.BR ldap_kerberos_bind_s()
routine.  It assumes the user already
has obtained a ticket granting ticket.  It takes \fIwho\fP, the DN
of the entry to bind as.  This routine does both steps of the
kerberos binding process synchronously.  The
.B ldap_kerberos_bind1_s()
and
.B ldap_kerberos_bind2_s()
routines allow synchronous access to the
individual steps, authenticating to the LDAP server and DSA, respectively.
The
.B ldap_kerberos_bind1()
and
.B ldap_kerberos_bind2()
routines provide equivalent asynchronous access.
.SH GENERAL AUTHENTICATION
The
.B ldap_bind()
and
.B ldap_bind_s()
routines can be used when the
authentication method to use needs to be selected at runtime.  They
both take an extra \fImethod\fP parameter selecting the authentication
method to use.  It should be set to one of LDAP_AUTH_SIMPLE,
LDAP_AUTH_KRBV41, or LDAP_AUTH_KRBV42, to select simple authentication,
kerberos authentication to the LDAP server, or kerberos authentication
to the DSA, respectively.
.B ldap_bind()
returns the message id of the request it initiates.
.B ldap_bind_s()
returns an LDAP error indication.
.SH UNBINDING
The
.B ldap_unbind()
call is used to unbind from the directory,
terminate the current association, and free the resources contained
in the \fIld\fP structure.  Once it is called, the connection to
the LDAP server is closed, and the \fIld\fP structure is invalid.
The
.B ldap_unbind_s()
call is just another name for
.BR ldap_unbind() ;
both of these calls are synchronous in nature.
.SH RE-BINDING WHILE FOLLOWING REFERRALS
The
.B ldap_set_rebind_proc()
call is used to set a routine that will be called back to obtain bind
credentials used when a new server is contacted during the following of
an LDAP referral.  Note that this function is only available when the
LDAP libraries are compiled with LDAP_REFERRALS defined and is only
used when the ld_options field in the LDAP structure has
LDAP_OPT_REFERRALS set (this is the default).  If
.B ldap_set_rebind_proc()
is never called, or if it is called with a NULL \fIrebindproc\fP
parameter, an unauthenticated simple LDAP bind will always be done
when chasing referrals.
.LP
\fIrebindproc\fP should be a function that is declared like this:
.LP
.nf
int rebindproc( LDAP *ld, char **whop, char **credp,
    int *methodp, int freeit );
.fi
.LP
The LDAP library will first call the rebindproc to obtain the
referral bind credentials, and the \fIfreeit\fP parameter will be
zero.  The \fIwhop\fP, \fIcredp\fP, and \fImethodp\fP should be
set as appropriate.  If the rebindproc returns LDAP_SUCCESS, referral
processing continues, and the rebindproc will be called a second
time with \fIfreeit\fP non-zero to give your application a chance to
free any memory allocated in the previous call.
.LP
If anything but LDAP_SUCCESS is returned by the first call to
the rebindproc, then referral processing is stopped and that error code
is returned for the original LDAP operation.
.SH ERRORS
Asynchronous routines will return -1 in case of error, setting the
\fIld_errno\fP parameter of the \fIld\fP structure.  Synchronous
routines return whatever \fIld_errno\fP is set to.  See
.BR ldap_error (3)
for more information.
.SH SEE ALSO
.BR ldap(3),
.BR ldap_error(3),
.BR ldap_open(3)
.SH ACKNOWLEDGEMENTS
.B	OpenLDAP
is developed and maintained by The OpenLDAP Project (http://www.openldap.org/).
.B	OpenLDAP
is derived from University of Michigan LDAP 3.3 Release.