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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[]);

       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 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 user‐
       Password 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 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 authentication 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  authentication  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, tak‐
       ing  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 credentials 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
       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 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_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 parame‐
       ter  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 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 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) function 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 authentication 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.
       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-edi‐
       tor.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 University of Michigan LDAP 3.3 Release.



OpenLDAP 2.4.40                                       2014/09/20                                         LDAP_BIND(3)