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.
       After 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  authentica-
       tion,  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 asynchro-
       nous versions of each variant of the bind call are provided.  All  rou-
       tines 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 return-
       ing the message id of the request it sent.  The result of the operation
       can be obtained by a subsequent call to ldap_result(3).

GENERAL AUTHENTICATION
       The ldap_bind() and ldap_bind_s() routines can be used when the authen-
       tication method to use needs to be selected at runtime.	They both take
       an  extra  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
       parameter  should  always  be  NULL.  ldap_sasl_bind_s() sends a single
       SASL bind request 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  authentica-
       tion  the  server's  credentials	 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 operation can be obtained
       by a subsequent call to ldap_result(3).	The result must	 be  addition-
       ally  parsed by ldap_parse_sasl_bind_result() to obtain any server cre-
       dentials sent from the server.

       Many SASL mechanisms require multiple message exchanges	to  perform  a
       complete	   authentication.    Applications    should   generally   use
       ldap_sasl_interactive_bind_s()	rather	 than	calling	  the	 basic
       ldap_sasl_bind() functions directly. The mechs parameter should contain
       a space-separated list of candidate mechanisms to use. If this  parame-
       ter 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 controls 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  defined	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 synchronous function, with three additional parameters.
       The actual SASL mechanism 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 parameter.   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
       application needs to bind to another server in order to follow a refer-
       ral or search continuation reference.

       The  function  takes ld, the rebind function, and the params, the arbi-
       trary data like state information which the client might need to	 prop-
       erly 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
       referred server if the application wants the libraries  to  follow  the
       referral.

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

       The  request parameter specifies the type of request that generated the
       referral.

       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
       function.  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 authen-
       tication	 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  synchro-
       nous 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_errno 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  Univer-
       sity of Michigan LDAP 3.3 Release.



OpenLDAP 2.4.40			  2014/09/20			  LDAP_BIND(3)