LDAP_BIND(3)                                                      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_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) that can negotiate  one
       of  many different kinds of authentication.  Both synchronous and asyn-
       chronous versions 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  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.

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 2.4.11                   2008/07/16                      LDAP_BIND(3)
