openldap/doc/man/man3/ldap_bind.3

.TH LDAP_BIND 3 "RELEASEDATE" "OpenLDAP LDVERSION"
.\" $OpenLDAP$
.\" Copyright 1998-2007 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.SH NAME
ldap_bind, ldap_bind_s, ldap_simple_bind, ldap_simple_bind_s, ldap_sasl_bind, ldap_sasl_bind_s, ldap_sasl_interactive_bind_s, ldap_parse_sasl_bind_result, ldap_unbind, ldap_unbind_s, ldap_unbind_ext, ldap_unbind_ext_s, ldap_set_rebind_proc \- LDAP bind routines
.SH LIBRARY
OpenLDAP LDAP (libldap, -lldap)
.SH SYNOPSIS
.nf
.B #include <ldap.h>
.LP
.BI "int ldap_bind(LDAP *" ld ", const char *" who ", const char *" cred ","
.RS
.BI "int " method ");"
.RE
.LP
.BI "int ldap_bind_s(LDAP *" ld ", const char *" who ", const char *" cred ","
.RS
.BI "int " method ");"
.RE
.LP
.BI "int ldap_simple_bind(LDAP *" ld ", const char *" who ", const char *" passwd ");"
.LP
.BI "int ldap_simple_bind_s(LDAP *" ld ", const char *" who ", const char *" passwd ");"
.LP
.BI "int ldap_sasl_bind(LDAP *" ld ", const char *" dn ", const char *" mechanism ","
.RS
.BI "struct berval *" cred ", LDAPControl *" sctrls "[],"
.BI "LDAPControl *" cctrls "[], int *" msgidp ");"
.RE
.LP
.BI "int ldap_sasl_bind_s(LDAP *" ld ", const char *" dn ", const char *" mechanism ","
.RS
.BI "struct berval *" cred ", LDAPControl *" sctrls "[],"
.BI "LDAPControl *" cctrls "[], struct berval **" servercredp ");"
.RE
.LP
.BI "int ldap_parse_sasl_bind_result(LDAP *" ld ", LDAPMessage *" res ","
.RS
.BI "struct berval **" servercredp ", int " freeit ");"
.RE
.LP
.BI "int ldap_sasl_interactive_bind_s(LDAP *" ld ", const char *" dn ","
.RS
.BI "const char *" mechs ","
.BI "LDAPControl *" sctrls "[], LDAPControl *" cctrls "[],"
.BI "unsigned " flags ", LDAP_SASL_INTERACT_PROC *" interact ","
.BI "void *" defaults ");"
.RE
.LP
.BI "int ldap_unbind(LDAP *" ld ");"
.LP
.BI "int ldap_unbind_s(LDAP *" ld ");"
.\" .LP
.\" .ft B
.\" void ldap_set_rebind_proc( ld, rebindproc )
.\" .ft
.\" LDAP *ld;
.\" int (*rebindproc)();
.LP
.BI "int ldap_unbind_ext(LDAP *" ld ", LDAPControl *" sctrls "[],"
.RS
.BI LDAPControl *" cctrls "[]);"
.RE
.LP
.BI "int ldap_unbind_ext_s(LDAP *" ld ", LDAPControl *" sctrls "[],"
.RS
.BI LDAPControl *" cctrls "[]);"
.RE
.LP
.BI "int ldap_set_rebind_proc (LDAP *" ld ", LDAP_REBIND_PROC *" ldap_proc ", void *" params);"
.SH DESCRIPTION
.LP
These routines provide various interfaces to the LDAP bind operation.
After an association with an LDAP server is made using
.BR ldap_init (3),
an LDAP bind operation should be performed before other operations are
attempted over the connection.  An LDAP bind is required when using
Version 2 of the LDAP protocol; it is optional for Version 3 but is
usually needed due to security considerations.
.LP
There are three types of bind calls, ones providing simple authentication,
ones providing SASL authentication, and general routines capable of doing
either simple or SASL authentication.
.LP
.B SASL
(Simple Authentication and Security Layer)
that can negotiate one of many different kinds of authentication.
Both synchronous and asynchronous versions of each variant of the bind
call are provided.  All routines
take \fIld\fP as their first parameter, as returned from
.BR ldap_init (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 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 LDAP_AUTH_SIMPLE
to select simple authentication.
.B ldap_bind()
returns the message id of the request it initiates.
.B ldap_bind_s()
returns an LDAP error indication.
.SH SASL AUTHENTICATION
Description still under construction...
.SH REBINDING
.LP
The
.B ldap_set_rebind_proc
function() sets the process to use for binding when an operation returns a
referral. This function is used when an application needs to bind to another server
in order to follow a referral or search continuation reference.
.LP
The function takes \fIld\fP, the \fIrebind\fP function, and the \fIparams\fP,
the arbitrary data like state information which the client might need to properly rebind.
The LDAP_OPT_REFERRALS option in the \fIld\fP must be set to ON for the libraries
to use the rebind function. Use the
.BR ldap_set_option
function to set the value.
.LP
The rebind function has the following syntax.
.B int rebind_function (LDAP *ld, const char *url,int request,ber_int_t   msgid);
.LP
The \fIld\fP parameter must be used by the application when binding to the
referred server if the application wants the libraries to follow the referral.
.LP
The \fIurl\fP parameter points to the URL referral string received from the LDAP server.
The LDAP application can use the 
.BR ldap_url_parse (3)
function to parse the string into its components.
.LP
The \fIrequest\fP parameter specifies the request operation that generated the referral. 
.LP
The \fImsgid\fP parameter specifies the message ID of the request generating the referral.
.LP
The LDAP libraries set all the parameters when they call the rebind function. The application
should not attempt to free either the ld or the url structures in the rebind function.
.LP
The application must supply to the rebind function the required authentication information such as,
user name, password, and certificates. The rebind function must use a synchronous bind method.
.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.
.LP
The
.B ldap_unbind_ext()
and
.B ldap_unbind_ext_s()
allows the operations to sepicify  controls.
.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 NOTES
If an anonymous bind is sufficient for the application,the rebind process
need not be provided. The LDAP libraries with the LDAP_OPT_REFERRALS option
set to ON (default value) will automatically follow referrals using an anonymous bind.
.LP
If the application needs stronger authentication than an anonymous bind,
you need to provide a rebind process for that authentication method.
The bind method must be synchronous.
.SH SEE ALSO
.BR ldap (3),
.BR ldap_error (3),
.BR ldap_open (3),
.BR ldap_set_option (3),
.BR ldap_url_parse (3)
.B RFC 4422
(http://www.rfc-editor.org),
.B Cyrus SASL
(http://asg.web.cmu.edu/sasl/)
.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.