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LDAP_BIND(3)		    Library Functions Manual		    LDAP_BIND(3)

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

LIBRARY
     OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS
     #include <ldap.h>

     int ldap_bind(LDAP *ld, const char *who, const char *cred,
	    int method);

     int ldap_bind_s(LDAP *ld, const char *who, const char *cred,
	    int method);

     int ldap_simple_bind(LDAP *ld, const char *who, const char *passwd);

     int ldap_simple_bind_s(LDAP *ld, const char *who, const char *passwd);

     int ldap_sasl_bind(LDAP *ld, const char *dn, const char *mechanism,
	    struct berval *cred, LDAPControl *sctrls[],
	    LDAPControl *cctrls[], int *msgidp);

     int ldap_sasl_bind_s(LDAP *ld, const char *dn, const char *mechanism,
	    struct berval *cred, LDAPControl *sctrls[],
	    LDAPControl *cctrls[], struct berval **servercredp);

     int ldap_parse_sasl_bind_result(LDAP *ld, LDAPMessage *res,
	    struct berval **servercredp, int freeit);

     int ldap_sasl_interactive_bind_s(LDAP *ld, const char *dn,
	    const char *mechs,
	    LDAPControl *sctrls[], LDAPControl *cctrls[],
	    unsigned flags, LDAP_SASL_INTERACT_PROC *interact,
	    void *defaults);

     int ldap_sasl_interactive_bind(LDAP *ld, const char *dn,
	    const char *mechs,
	    LDAPControl *sctrls[], LDAPControl *cctrls[],
	    unsigned flags, LDAP_SASL_INTERACT_PROC *interact,
	    void *defaults, LDAPMessage *result,
	    const char **rmechp, int *msgidp);

     int (LDAP_SASL_INTERACT_PROC)(LDAP *ld, unsigned flags, void *defaults, void *sasl_interact);

     int ldap_unbind(LDAP *ld);

     int ldap_unbind_s(LDAP *ld);

     int ldap_unbind_ext(LDAP *ld, LDAPControl *sctrls[],
	    LDAPControl *cctrls[]);

     int ldap_unbind_ext_s(LDAP *ld, LDAPControl *sctrls[],
	    LDAPControl *cctrls[]);

     int ldap_set_rebind_proc (LDAP *ld, LDAP_REBIND_PROC *ldap_proc, void *params);

     int (LDAP_REBIND_PROC)(LDAP *ld, LDAP_CONST char *url, ber_tag_t request, ber_int_t msgid, void *params);

DESCRIPTION
     These routines provide various interfaces to the LDAP bind operation.   Af-
     ter  an association with an LDAP server is made using 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.

     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.

     SASL  (Simple  Authentication and Security Layer) can negotiate one of many
     different kinds of authentication.  Both synchronous and asynchronous  ver-
     sions  of each variant of the bind call are provided.  All routines take ld
     as their first parameter, as returned from ldap_init(3).

SIMPLE AUTHENTICATION
     The simplest form of the bind call is ldap_simple_bind_s().  It  takes  the
     DN  to  bind  as  in who, and the userPassword associated with the entry in
     passwd.  It returns an LDAP  error  indication  (see  ldap_error(3)).   The
     ldap_simple_bind()  call  is  asynchronous,  taking the same parameters but
     only initiating the bind operation and returning the message id of the  re-
     quest it sent.  The result of the operation can be obtained by a subsequent
     call   to	 ldap_result(3).    The   ldap_sasl_bind_s()   and  asynchronous
     ldap_sasl_bind() functions can also be used to make a simple bind by  using
     LDAP_SASL_SIMPLE as the SASL mechanism.

GENERAL AUTHENTICATION
     The ldap_bind() and ldap_bind_s() routines can be used when the authentica-
     tion  method to use needs to be selected at runtime.  They both take an ex-
     tra method parameter selecting the authentication method to use.  It should
     be set to LDAP_AUTH_SIMPLE to select  simple  authentication.   ldap_bind()
     returns  the message id of the request it initiates.  ldap_bind_s() returns
     an LDAP error indication.

SASL AUTHENTICATION
     For SASL binds the server always ignores any provided DN, so the dn parame-
     ter should always be NULL.  ldap_sasl_bind_s() sends a single SASL bind re-
     quest with the given SASL mechanism and credentials in the cred  parameter.
     The  format  of the credentials depends on the particular SASL mechanism in
     use. For mechanisms that provide mutual authentication the server's creden-
     tials will be returned in the servercredp parameter.  The	routine  returns
     an LDAP error indication (see ldap_error(3)).  The ldap_sasl_bind() call is
     asynchronous,  taking  the same parameters but only sending the request and
     returning the message id of the request it sent. The result of  the  opera-
     tion  can	be  obtained by a subsequent call to ldap_result(3).  The result
     must be additionally parsed by ldap_parse_sasl_bind_result() to obtain  any
     server credentials sent from the server.

     Any returned server credentials should be freed using ber_bvfree().

     Many  SASL  mechanisms require multiple message exchanges to perform a com-
     plete authentication. Applications should generally use  ldap_sasl_interac-
     tive_bind_s()  rather than calling the basic ldap_sasl_bind() functions di-
     rectly. The mechs parameter should contain a space-separated list of candi-
     date mechanisms to use. If this parameter is NULL or empty the library will
     query the supportedSASLMechanisms attribute from the server's  rootDSE  for
     the  list	of SASL mechanisms the server supports. The flags parameter con-
     trols the interaction used to retrieve any  necessary  SASL  authentication
     parameters and should be one of:

     LDAP_SASL_AUTOMATIC
	    use defaults if available, prompt otherwise

     LDAP_SASL_INTERACTIVE
	    always prompt

     LDAP_SASL_QUIET
	    never prompt

     The  interact  function  uses the provided defaults to handle requests from
     the SASL library for particular authentication parameters. There is no  de-
     fined  format  for  the defaults information; it is up to the caller to use
     whatever format is appropriate for the  supplied  interact  function.   The
     sasl_interact  parameter  comes from the underlying SASL library. When used
     with Cyrus SASL this is an array of sasl_interact_t structures.  The  Cyrus
     SASL library will prompt for a variety of inputs, including:

     SASL_CB_GETREALM
	    the realm for the authentication attempt

     SASL_CB_AUTHNAME
	    the username to authenticate

     SASL_CB_PASS
	    the password for the provided username

     SASL_CB_USER
	    the username to use for proxy authorization

     SASL_CB_NOECHOPROMPT
	    generic prompt for input with input echoing disabled

     SASL_CB_ECHOPROMPT
	    generic prompt for input with input echoing enabled

     SASL_CB_LIST_END
	    indicates the end of the array of prompts

     See the Cyrus SASL documentation for more details.

     Applications  which  need	to  manage  connections  asynchronously  may use
     ldap_sasl_interactive_bind() instead of the synchronous version.	A  valid
     mechs  parameter  must be supplied, otherwise the library will be forced to
     query the server for a list of supported mechanisms, and this query will be
     performed synchronously.  The other parameters are the same as for the syn-
     chronous function, with three additional parameters.  The actual SASL mech-
     anism that was used, and the message ID for use with ldap_result() will  be
     returned  in rmechp and msgidp, respectively.  The value in rmechp must not
     be modified by the caller and must be passed back on each subsequent  call.
     The  message obtained from ldap_result() must be passed in the result para-
     meter.  This parameter must be NULL when initiating a new Bind. The  caller
     must  free  the  result  message after each call using ldap_msgfree().  The
     ldap_sasl_interactive_bind() function returns an LDAP result code.  If  the
     code  is  LDAP_SASL_BIND_IN_PROGRESS then the Bind is not complete yet, and
     this function must be called again with the next result from the server.

REBINDING
     The ldap_set_rebind_proc function() sets the process  to  use  for  binding
     when  an operation returns a referral. This function is used when an appli-
     cation needs to bind to another server in order to  follow  a  referral  or
     search continuation reference.

     The  function  takes ld, the rebind function, and the params, the arbitrary
     data like state information which the client might need to properly rebind.
     The LDAP_OPT_REFERRALS option in the ld must be set to ON for the libraries
     to use the rebind function. Use the ldap_set_option  function  to	set  the
     value.

     The rebind function parameters are as follows:

     The  ld  parameter  must be used by the application when binding to the re-
     ferred server if the application wants the libraries to follow  the  refer-
     ral.

     The  url parameter points to the URL referral string received from the LDAP
     server.  The LDAP application can use  the  ldap_url_parse(3)  function  to
     parse the string into its components.

     The  request parameter specifies the type of request that generated the re-
     ferral.

     The msgid parameter specifies the message ID of the request generating  the
     referral.

     The  params  parameter  is  the  same  value  as  passed  originally to the
     ldap_set_rebind_proc() function.

     The LDAP libraries set all the parameters when they call the  rebind  func-
     tion.  The  application should not attempt to free either the ld or the url
     structures in the rebind function.

     The application must supply to the rebind function the required authentica-
     tion information such as, user name, password, and certificates. The rebind
     function must use a synchronous bind method.

UNBINDING
     The ldap_unbind() call is used to unbind from the directory, terminate  the
     current  association, and free the resources contained in the ld structure.
     Once it is called, the connection to the LDAP server is closed, and the  ld
     structure	is  invalid.   The ldap_unbind_s() call is just another name for
     ldap_unbind(); both of these calls are synchronous in nature.

     The ldap_unbind_ext() and	ldap_unbind_ext_s()  allows  the  operations  to
     specify  controls.

ERRORS
     Asynchronous routines will return -1 in case of error, setting the ld_errno
     parameter of the ld structure.  Synchronous routines return whatever ld_er-
     rno is set to.  See ldap_error(3) for more information.

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.

     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.

SEE ALSO
     ldap(3), ldap_error(3), ldap_open(3), ldap_set_option(3), ldap_url_parse(3)
     RFC	4422	    (http://www.rfc-editor.org),	Cyrus	    SASL
     (http://asg.web.cmu.edu/sasl/)

ACKNOWLEDGEMENTS
     OpenLDAP Software is developed  and  maintained  by  The  OpenLDAP  Project
     <http://www.openldap.org/>.   OpenLDAP Software is derived from the Univer-
     sity of Michigan LDAP 3.3 Release.

OpenLDAP 2.6.13 		   2026/03/09			    LDAP_BIND(3)

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