Net::LDAP(3) User Contributed Perl Documentation Net::LDAP(3)
NAME
Net::LDAP - Lightweight Directory Access Protocol
SYNOPSIS
use Net::LDAP;
$ldap = Net::LDAP->new( 'ldap.bigfoot.com' ) or die "$@";
$mesg = $ldap->bind ; # an anonymous bind
$mesg = $ldap->search( # perform a search
base => "c=US",
filter => "(&(sn=Barr) (o=Texas Instruments))"
);
$mesg->code && die $mesg->error;
foreach $entry ($mesg->entries) { $entry->dump; }
$mesg = $ldap->unbind; # take down session
$ldap = Net::LDAP->new( 'ldap.umich.edu' );
# bind to a directory with dn and password
$mesg = $ldap->bind( 'cn=root, o=University of Michigan, c=us',
password => 'secret'
);
$result = $ldap->add( 'cn=Barbara Jensen, o=University of Michigan, c=US',
attr => [
'cn' => ['Barbara Jensen', 'Barbs Jensen'],
'sn' => 'Jensen',
'mail' => 'b.jensen@umich.edu',
'objectclass' => ['top', 'person',
'organizationalPerson',
'inetOrgPerson' ],
]
);
$result->code && warn "failed to add entry: ", $result->error ;
$mesg = $ldap->unbind; # take down session
DESCRIPTION
Net::LDAP is a collection of modules that implements a LDAP services API for Perl programs. The
module may be used to search directories or perform maintenance functions such as adding, deleting or
modifying entries.
This document assumes that the reader has some knowledge of the LDAP protocol.
CONSTRUCTOR
new ( HOST, OPTIONS )
Creates a new Net::LDAP object and opens a connection to the named host.
"HOST" may be a host name or an IP number. TCP port may be specified after the host name followed
by a colon (such as localhost:10389). The default TCP port for LDAP is 389.
You can also specify a URI, such as 'ldaps://127.0.0.1:666' or
'ldapi://%2fvar%2flib%2fldap_sock'. Note that '%2f's in the LDAPI socket path will be translated
into '/'. This is to support LDAP query options like base, search etc. although the query part of
the URI will be ignored in this context. If port was not specified in the URI, the default is
either 389 or 636 for 'LDAP' and 'LDAPS' schemes respectively.
"HOST" may also be a reference to an array of hosts, host-port pairs or URIs to try. Each will be
tried in order until a connection is made. Only when all have failed will the result of "undef"
be returned.
port => N
Port to connect to on the remote server. May be overridden by "HOST".
timeout => N
Timeout passed to IO::Socket when connecting the remote server. (Default: 120)
multihomed => N
Will be passed to IO::Socket as the "MultiHomed" parameter when connecting to the remote
server
localaddr => HOST
Will be passed to IO::Socket as the "LocalAddr" parameter, which sets the client's IP address
(as opposed to the server's IP address.)
debug => N
Set the debug level. See the debug method for details.
async => 1
Perform all operations asynchronously.
onerror => 'die' | 'warn' | undef | sub { ... }
In synchronous mode, change what happens when an error is detected.
'die'
Net::LDAP will croak whenever an error is detected.
'warn'
Net::LDAP will warn whenever an error is detected.
undef
Net::LDAP will warn whenever an error is detected and "-w" is in effect. The method that
was called will return "undef".
sub { ... }
The given sub will be called in a scalar context with a single argument, the result
message. The value returned will be the return value for the method that was called.
version => N
Set the protocol version being used (default is LDAPv3). This is useful if you want to talk
to an old server and therefore have to use LDAPv2.
Example
$ldap = Net::LDAP->new( 'remote.host', async => 1 );
LDAPS connections have some extra valid options, see the start_tls method for details. Note the
default value for 'sslversion' for LDAPS is 'sslv2/3', and the default port for LDAPS is 636.
For LDAPI connections, HOST is actually the location of a UNIX domain socket to connect to. The
default location is '/var/lib/ldapi'.
METHODS
Each of the following methods take as arguments some number of fixed parameters followed by options,
these options are passed in a named fashion, for example
$mesg = $ldap->bind( "cn=me,o=example", password => "mypasswd");
The return value from these methods is an object derived from the Net::LDAP::Message class. The
methods of this class allow you to examine the status of the request.
abandon ( ID, OPTIONS )
Abandon a previously issued request. "ID" may be a number or an object which is a sub-class of
Net::LDAP::Message, returned from a previous method call.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below
callback => CALLBACK
See "CALLBACKS" below
Example
$res = $ldap->search( @search_args );
$mesg = $ldap->abandon( $res ); # This could be written as $res->abandon
add ( DN, OPTIONS )
Add a new entry to the directory. "DN" can be either a Net::LDAP::Entry object or a string.
attrs => [ ATTR => VALUE, ... ]
"VALUE" should be a string if only a single value is wanted, or a reference to an array of
strings if multiple values are wanted.
This argument is not used if "DN" is a Net::LDAP::Entry object.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below
callback => CALLBACK
See "CALLBACKS" below
Example
# $entry is an object of class Net::LDAP::Entry
$mesg = $ldap->add( $entry );
$mesg = $ldap->add( $dn,
attrs => [
name => 'Graham Barr',
attr => 'value1',
attr => 'value2',
multi => [qw(value1 value2)]
]
);
bind ( DN, OPTIONS )
Bind (log in) to the server. "DN" is the DN to bind with. An anonymous bind may be done by
calling bind without any arguments.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below
callback => CALLBACK
See "CALLBACKS" below
noauth | anonymous => 1
Bind without any password. The value passed with this option is ignored.
password => PASSWORD
Bind with the given password.
sasl => SASLOBJ
Bind using a SASL mechanism. The argument given should be a sub-class of Authen::SASL.
Example
$mesg = $ldap->bind; # Anonymous bind
$mesg = $ldap->bind( $dn, password => $password );
# $sasl is an object of class Authen::SASL
$mesg = $ldap->bind( $dn, sasl => $sasl, version => 3 );
compare ( DN, OPTIONS )
Compare values in an attribute in the entry given by "DN" on the server. "DN" may be a string or
a Net::LDAP::Entry object.
attr => ATTR
The name of the attribute to compare.
value => VALUE
The value to compare with.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below.
callback => CALLBACK
See "CALLBACKS" below.
Example
$mesg = $ldap->compare( $dn,
attr => 'cn',
value => 'Graham Barr'
);
delete ( DN, OPTIONS )
Delete the entry given by "DN" from the server. "DN" may be a string or a Net::LDAP::Entry
object.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below.
callback => CALLBACK
See "CALLBACKS" below.
Example
$mesg = $ldap->delete( $dn );
moddn ( DN, OPTIONS )
Rename the entry given by "DN" on the server. "DN" may be a string or a Net::LDAP::Entry object.
newrdn => RDN
This value should be a new RDN to assign to "DN".
deleteoldrdn => 1
This option should be passwd if the existing RDN is to be deleted.
newsuperior => NEWDN
If given this value should be the DN of the new superior for "DN".
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below.
callback => CALLBACK
See "CALLBACKS" below.
Example
$mesg = $ldap->moddn( $dn, newrdn => 'cn=Graham Barr' );
modify ( DN, OPTIONS )
Modify the contents of the entry given by "DN" on the server. "DN" may be a string or a
Net::LDAP::Entry object.
add => { ATTR => VALUE, ... }
Add more attributes or values to the entry. "VALUE" should be a string if only a single value
is wanted in the attribute, or a reference to an array of strings if multiple values are
wanted.
delete => [ ATTR, ... ]
Delete complete attributes from the entry.
delete => { ATTR => VALUE, ... }
Delete individual values from an attribute. "VALUE" should be a string if only a single value
is being deleted from the attribute, or a reference to an array of strings if multiple values
are being deleted.
replace => { ATTR => VALUE, ... }
Replace any existing values in each given attribute with "VALUE". "VALUE" should be a string
if only a single value is wanted in the attribute, or a reference to an array of strings if
multiple values are wanted. A reference to an empty array will remove the entire attribute.
changes => [ OP => [ ATTR => VALUE ], ... ]
This is an alternative to add, delete and replace where the whole operation can be given in a
single argument. "OP" should be add, delete or replace. "VALUE" should be either a string or
a reference to an array of strings, as before.
Use this form if you want to control the order in which the operations will be performed.
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below.
callback => CALLBACK
See "CALLBACKS" below.
Example
$mesg = $ldap->modify( $dn, add => { sn => 'Barr' } );
$mesg = $ldap->modify( $dn, delete => [qw(faxNumber)] );
$mesg = $ldap->modify( $dn, delete => { 'telephoneNumber' => '911' } );
$mesg = $ldap->modify( $dn, replace => { 'mail' => 'gbarr@pobox.com' } );
$mesg = $ldap->modify( $dn,
changes => [
# add sn=Barr
add => [ sn => 'Barr' ],
# delete all fax numbers
delete => [ faxNumber => []],
# delete phone number 911
delete => [ telephoneNumber => ['911']],
# change email address
replace => [ mail => 'gbarr@pobox.com']
]
);
search ( OPTIONS )
Search the directory using a given filter. This can be used to read attributes from a single
entry, from entries immediately below a particular entry, or a whole subtree of entries.
The result is an object of class Net::LDAP::Search.
base => DN
The DN that is the base object entry relative to which the search is to be performed.
scope => 'base' | 'one' | 'sub'
By default the search is performed on the whole tree below the specified base object. This
maybe changed by specifying a "scope" parameter with one of the following values:
base
Search only the base object.
one Search the entries immediately below the base object.
sub Search the whole tree below (and including) the base object. This is the default.
deref => 'never' | 'search' | 'find' | 'always'
By default aliases are dereferenced to locate the base object for the search, but not when
searching subordinates of the base object. This may be changed by specifying a "deref"
parameter with one of the following values:
never
Do not dereference aliases in searching or in locating the base object of the search.
search
Dereference aliases in subordinates of the base object in searching, but not in locating
the base object of the search.
find
Dereference aliases in locating the base object of the search, but not when searching
subordinates of the base object. This is the default.
always
Dereference aliases both in searching and in locating the base object of the search.
sizelimit => N
A sizelimit that restricts the maximum number of entries to be returned as a result of the
search. A value of 0, and the default, means that no restriction is requested. Servers may
enforce a maximum number of entries to return.
timelimit => N
A timelimit that restricts the maximum time (in seconds) allowed for a search. A value of 0
(the default), means that no timelimit will be requested.
typesonly => 1
Only attribute types (no values) should be returned. Normally attribute types and values are
returned.
filter => FILTER
A filter that defines the conditions an entry in the directory must meet in order for it to
be returned by the search. This may be a string or a Net::LDAP::Filter object. Values inside
filters may need to be escaped to avoid security problems; see Net::LDAP::Filter for a
definition of the filter format, including the escaping rules.
attrs => [ ATTR, ... ]
A list of attributes to be returned for each entry that matches the search filter.
If not specified, then the server will return the attributes that are specified as accessible
by default given your bind credentials.
Certain additional attributes such as "createTimestamp" and other operational attributes may
also be available for the asking:
$mesg = $ldap->search( ... ,
attrs => ['createTimestamp']
);
To retrieve the default attributes and additional ones, use '*'.
$mesg = $ldap->search( ... ,
attrs => ['*', 'createTimestamp']
);
To retrieve no attributes (the server only returns the DNs of matching entries), use '1.1':
$mesg = $ldap->search( ... ,
attrs => ['1.1']
);
control => CONTROL
control => [ CONTROL, ... ]
See "CONTROLS" below.
callback => CALLBACK
See "CALLBACKS" below.
Example
$mesg = $ldap->search(
base => $base_dn,
scope => 'sub',
filter => '(|(objectclass=rfc822mailgroup)(sn=jones))'
);
Net::LDAP::LDIF->new( \*STDOUT,"w" )->write( $mesg->entries );
start_tls ( OPTIONS )
Calling this method will convert the existing connection to using Transport Layer Security (TLS),
which provides an encrypted connection. This is only possible if the connection uses LDAPv3, and
requires that the server advertizes support for LDAP_EXTENSION_START_TLS. Use
"supported_extension" in Net::LDAP::RootDSE to check this.
verify => 'none' | 'optional' | 'require'
How to verify the server's certificate:
none
The server may provide a certificate but it will not be checked - this may mean you are
be connected to the wrong server
optional
Verify only when the server offers a certificate
require
The server must provide a certificate, and it must be valid.
If you set verify to optional or require, you must also set either cafile or capath. The most
secure option is require.
sslversion => 'sslv2' | 'sslv3' | 'sslv2/3' | 'tlsv1'
This defines the version of the SSL/TLS protocol to use. Defaults to 'tlsv1'.
ciphers => CIPHERS
Specify which subset of cipher suites are permissible for this connection, using the standard
OpenSSL string format. The default value is 'ALL', which permits all ciphers, even those that
don't encrypt.
clientcert => '/path/to/cert.pem'
clientkey => '/path/to/key.pem'
keydecrypt => sub { ... }
If you want to use the client to offer a certificate to the server for SSL authentication
(which is not the same as for the LDAP Bind operation) then set clientcert to the user's
certificate file, and clientkey to the user's private key file. These files must be in PEM
format.
If the private key is encrypted (highly recommended) then keydecrypt should be a subroutine
that returns the decrypting key. For example:
$ldap = Net::LDAP->new( 'myhost.example.com', version => 3 );
$mesg = $ldap->start_tls(
verify => 'require',
clientcert => 'mycert.pem',
clientkey => 'mykey.pem',
keydecrypt => sub { 'secret'; },
capath => '/usr/local/cacerts/'
);
capath => '/path/to/servercerts/'
cafile => '/path/to/servercert.pem'
When verifying the server's certificate, either set capath to the pathname of the directory
containing CA certificates, or set cafile to the filename containing the certificate of the
CA who signed the server's certificate. These certificates must all be in PEM format.
The directory in 'capath' must contain certificates named using the hash value of the
certificates' subject names. To generate these names, use OpenSSL like this in Unix:
ln -s cacert.pem `openssl x509 -hash -noout < cacert.pem`.0
(assuming that the certificate of the CA is in cacert.pem.)
unbind ( )
The unbind method does not take any parameters and will unbind you from the server. Some servers
may allow you to re-bind or perform other operations after unbinding. If you wish to switch to
another set of credentials while continuing to use the same connection, re-binding with another
DN and password, without unbind-ing, will generally work.
Example
$mesg = $ldap->unbind;
The following methods are for convenience, and do not return "Net::LDAP::Message" objects.
async ( VALUE )
If "VALUE" is given the async mode will be set. The previous value will be returned. The value is
true if LDAP operations are being performed asynchronously.
certificate ( )
Returns an X509_Certificate object containing the server's certificate. See the IO::Socket::SSL
documentation for information about this class.
For example, to get the subject name (in a peculiar OpenSSL-specific format, different from RFC
1779 and RFC 2253) from the server's certificate, do this:
print "Subject DN: " . $ldaps->certificate->subject_name . "\n";
cipher ( )
Returns the cipher mode being used by the connection, in the string format used by OpenSSL.
debug ( VALUE )
If "VALUE" is given the debug bit-value will be set. The previous value will be returned. Debug
output will be sent to "STDERR". The bits of this value are:
1 Show outgoing packets (using asn_hexdump).
2 Show incoming packets (using asn_hexdump).
4 Show outgoing packets (using asn_dump).
8 Show incoming packets (using asn_dump).
The default value is 0.
disconnect ( )
Disconnect from the server
root_dse ( OPTIONS )
The root_dse method retrieves cached information from the server's rootDSE.
attrs => [ ATTR, ... ]
A reference to a list of attributes to be returned. If not specified, then the following
attributes will be requested
subschemaSubentry
namingContexts
altServer
supportedExtension
supportedFeatures
supportedControl
supportedSASLMechanisms
supportedLDAPVersion
The result is an object of class Net::LDAP::RootDSE.
Example
my $root = $ldap->root_dse;
# get naming Context
$root->get_value( 'namingContext', asref => 1 );
# get supported LDAP versions
$root->supported_version;
As the root DSE may change in certain circumstances - for instance when you change the connection
using start_tls - you should always use the root_dse method to return the most up-to-date copy of
the root DSE.
schema ( OPTIONS )
Read schema information from the server.
The result is an object of class Net::LDAP::Schema. Read this documentation for further
information about methods that can be performed with this object.
dn => DN
If a DN is supplied, it will become the base object entry from which the search for schema
information will be conducted. If no DN is supplied the base object entry will be determined
from the rootDSE entry.
Example
my $schema = $ldap->schema;
# get objectClasses
@ocs = $schema->all_objectclasses;
# Get the attributes
@atts = $schema->all_attributes;
socket ( )
Returns the underlying "IO::Socket" object being used.
sync ( MESG )
Wait for a given "MESG" request to be completed by the server. If no "MESG" is given, then wait
for all outstanding requests to be completed.
Returns an error code defined in Net::LDAP::Constant.
version ( )
Returns the version of the LDAP protocol that is being used.
CONTROLS
Many of the methods described above accept a control option. This allows the user to pass controls
to the server as described in LDAPv3.
A control is a reference to a HASH and should contain the three elements below. If any of the
controls are blessed then the method "to_asn" will be called which should return a reference to a
HASH containing the three elements described below.
type => OID
This element must be present and is the name of the type of control being requested.
critical => FLAG
critical is optional and should be a boolean value, if it is not specified then it is assumed to
be false.
value => VALUE
If the control being requested requires a value then this element should hold the value for the
server.
CALLBACKS
Most of the above commands accept a callback option. This option should be a reference to a
subroutine. This subroutine will be called for each packet received from the server as a response to
the request sent.
When the subroutine is called the first argument will be the Net::LDAP::Message object which was
returned from the method.
If the request is a search then multiple packets can be received from the server. Each entry is
received as a separate packet. For each of these the subroutine will be called with a
Net::LDAP::Entry object as the second argument.
During a search the server may also send a list of references. When such a list is received then the
subroutine will be called with a Net::LDAP::Reference object as the second argument.
LDAP ERROR CODES
Net::LDAP also exports constants for the error codes that can be received from the server, see
Net::LDAP::Constant.
SEE ALSO
Net::LDAP::Constant, Net::LDAP::Control, Net::LDAP::Entry, Net::LDAP::Filter, Net::LDAP::Message,
Net::LDAP::Reference, Net::LDAP::Search, Net::LDAP::RFC
The homepage for the perl-ldap modules can be found at http://perl-ldap.sourceforge.net/
ACKNOWLEDGEMENTS
This document is based on a document originally written by Russell Fulton <r.fulton@auckland.ac.nz>.
Chris Ridd <chris.ridd@isode.com> for the many hours spent testing and contribution of the ldap*
command line utilities.
MAILING LIST
A discussion mailing list is hosted by sourceforge at <perl-ldap@perl.org> No subscription is
necessary!
BUGS
We hope you do not find any, but if you do please report them to the mailing list.
If you have a patch, please send it as an attachment to the mailing list.
AUTHOR
Graham Barr <gbarr@pobox.com>
COPYRIGHT
Copyright (c) 1997-2004 Graham Barr. All rights reserved. This program is free software; you can
redistribute it and/or modify it under the same terms as Perl itself.
perl v5.8.8 2005-04-25 Net::LDAP(3)
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