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

Provided by: libldap-dev_2.5.18+dfsg-0ubuntu0.22.04.2_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).  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 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.

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

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.