Ubuntu Manpage: ldap_bind, ldap_bind_s, ldap_simple_bind, ldap_simple_bind_s, ldap_sasl_bind, ldap_sasl_bind

Provided by: libldap2-dev_2.4.45+dfsg-1ubuntu1.11_amd64

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  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  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 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, 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 additionally 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_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
       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.

       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.

ACKNOWLEDGEMENTS

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