Provided by: tcllib_1.21+dfsg-1_all 
NAME
ldap - LDAP client
SYNOPSIS
package require Tcl 8.5
package require ldap ?1.10.1?
::ldap::connect host ?port?
::ldap::tlsoptions reset
::ldap::tlsoptions ?opt1 val1? ?opt2 val2? ...
::ldap::secure_connect host ?port?
::ldap::secure_connect host ?port? ?verify_cert? ?sni_servername?
::ldap::disconnect handle
::ldap::starttls handle
::ldap::starttls handle ?cafile? ?certfile? ?keyfile? ?verify_cert? ?sni_servername?
::ldap::bind handle ?name? ?password?
::ldap::bindSASL handle ?name? ?password?
::ldap::unbind handle
::ldap::search handle baseObject filterString attributes options
::ldap::searchInit handle baseObject filterString attributes options
::ldap::searchNext handle
::ldap::searchEnd handle
::ldap::modify handle dn attrValToReplace ?attrToDelete? ?attrValToAdd?
::ldap::modifyMulti handle dn attrValToReplace ?attrValToDelete? ?attrValToAdd?
::ldap::add handle dn attrValueTuples
::ldap::addMulti handle dn attrValueTuples
::ldap::delete handle dn
::ldap::modifyDN handle dn newrdn ?deleteOld? ?newSuperior?
::ldap::info ip handle
::ldap::info bound handle
::ldap::info bounduser handle
::ldap::info connections
::ldap::info tls handle
::ldap::info tlsstatus handle
::ldap::info saslmechanisms handle
::ldap::info control handle
::ldap::info extensions extensions
::ldap::info whoami handle
________________________________________________________________________________________________________________
DESCRIPTION
The ldap package provides a Tcl-only client library for the LDAPv3 protocol as specified in RFC 4511
(http://www.rfc-editor.org/rfc/rfc4511.txt). It works by opening the standard (or secure) LDAP socket on
the server, and then providing a Tcl API to access the LDAP protocol commands. All server errors are
returned as Tcl errors (thrown) which must be caught with the Tcl catch command.
TLS SECURITY CONSIDERATIONS
This package uses the TLS package to handle the security for LDAPS connections.
Policy decisions like the set of protocols to support and what ciphers to use are not the responsibility
of TLS, nor of this package itself however. Such decisions are the responsibility of whichever
application is using the package, and are likely influenced by the set of servers the application will
talk to as well.
For example, in light of the recent POODLE attack
[http://googleonlinesecurity.blogspot.co.uk/2014/10/this-poodle-bites-exploiting-ssl-30.html] discovered
by Google many servers will disable support for the SSLv3 protocol. To handle this change the
applications using TLS must be patched, and not this package, nor TLS itself. Such a patch may be as
simple as generally activating tls1 support, as shown in the example below.
ldap::tlsoptions -tls1 1 -ssl2 0 -ssl3 0 ;# forcibly activate support for the TLS1 protocol
... your own application code ...
COMMANDS
::ldap::connect host ?port?
Opens a LDAPv3 connection to the specified host, at the given port, and returns a token for the
connection. This token is the handle argument for all other commands. If no port is specified it
will default to 389.
The command blocks until the connection has been established, or establishment definitely failed.
::ldap::tlsoptions reset
This command resets TLS options to default values. It returns the set of options. Using this
command is incompatible with the obsolete form of ::ldap::secure_connect and ::ldap_starttls.
::ldap::tlsoptions ?opt1 val1? ?opt2 val2? ...
This commands adds one or more options to some value, and may be used more than one time in order
to add options in several steps. A complete description of options may be found in the tls
package documentation. Valid options and values are:
-cadir directory
Provide the directory containing the CA certificates. No default.
-cafile file
Provide the CA file. No default.
-cipher string
Provide the cipher suites to use. No default.
-dhparams file
Provide a Diffie-Hellman parameters file. No default.
-request boolean
Request a certificate from peer during SSL handshake. Default: true.
-require boolean
Require a valid certificate from peer during SSL handshake. If this is set to true then
-request must also be set to true. Default: false
-servername host
Only available if the OpenSSL library the TLS package is linked against supports the TLS
hostname extension for 'Server Name Indication' (SNI). Use to name the logical host we are
talking to and expecting a certificate for. No default.
-ssl2 bool
Enable use of SSL v2. Default: false
-ssl3 bool
Enable use of SSL v3. Default: false
-tls1 bool
Enable use of TLS v1 Default: true
-tls1.1 bool
Enable use of TLS v1.1 Default: true
-tls1.2 bool
Enable use of TLS v1.2 Default: true
This command returns the current set of TLS options and values. In particular, one may use this command
without any arguments to get the current set of options.
Using this command is incompatible with the obsolete form of ::ldap::secure_connect and ::ldap_starttls
(see below).
::ldap::secure_connect host ?port?
Like ::ldap::connect, except that the created connection is secured by SSL. The port defaults to
636. This command depends on the availability of the package TLS, which is a SSL binding for Tcl.
If TLS is not available, then this command will fail.
TLS options are specified with ::ldap::tlsoptions.
The command blocks until the connection has been established, or establishment definitely failed.
::ldap::secure_connect host ?port? ?verify_cert? ?sni_servername?
Note: this form of the command is deprecated, since TLS options had to be specified with a
combination of parameters to this command (verify_cert and sni_servername) and arguments to
::tls::init (from package tls) for example to setup defaults for trusted certificates. Prefer the
above form (without the verify_cert and sni_servername parameters) and set TLS options with
::ldap::tlsoptions.
If verify_cert is set to 1, the default, this checks the server certificate against the known
hosts. If sni_servername is set, the given hostname is used as the hostname for Server Name
Indication in the TLS handshake.
Use ::tls::init to setup defaults for trusted certificates.
TLS supports different protocol levels. In common use are the versions 1.0, 1.1 and 1.2. By
default all those versions are offered. If you need to modify the acceptable protocols, you can
change the ::ldap::tlsProtocols list (deprecated).
::ldap::disconnect handle
Closes the ldap connection refered to by the token handle. Returns the empty string as its result.
::ldap::starttls handle
Start TLS negotiation on the connection denoted by handle, with TLS parameters set with
::ldap::tlsoptions.
::ldap::starttls handle ?cafile? ?certfile? ?keyfile? ?verify_cert? ?sni_servername?
Note: this form of the command is deprecated, since TLS options had to be specified with a
combination of parameters to this command (cafile, certfile, keyfile, verify_cert and
sni_servername) and arguments to ::tls::init (from package tls). Prefer the above form (without
specific TLS arguments) and set TLS options with ::ldap::tlsoptions.
Start TLS negotiation on the connection denoted by handle. You need to set at least the cafile
argument to a file with trusted certificates, if verify_cert is 1, which is the default. The
sni_servername can be used to signal a different hostname during the TLS handshake. The announced
protocols are determined in the same way as ::ldap::secure_connect. You can specify a TLS client
certificate with the certfile and keyfile options.
::ldap::bind handle ?name? ?password?
This command authenticates the ldap connection refered to by the token in handle, with a user name
and associated password. It blocks until a response from the ldap server arrives. Its result is
the empty string. Both name and passwd default to the empty string if they are not specified. By
leaving out name and passwd you can make an anonymous bind to the ldap server. You can issue
::ldap::bind again to bind with different credentials.
::ldap::bindSASL handle ?name? ?password?
This command uses SASL authentication mechanisms to do a multistage bind. Its otherwise identical
to the standard ::ldap::bind. This feature is currently experimental and subject to change. See
the documentation for the SASL and the "SASL.txt" in the tcllib CVS repository for details how to
setup and use SASL with openldap.
::ldap::unbind handle
This command asks the ldap server to release the last bind done for the connection refered to by
the token in handle. The handle is invalid after the unbind, as the server closes the connection.
So this is effectivly just a more polite disconnect operation.
::ldap::search handle baseObject filterString attributes options
This command performs a LDAP search below the baseObject tree using a complex LDAP search
expression filterString and returns the specified attributes of all matching objects (DNs). If the
list of attributes was empty all attributes are returned. The command blocks until it has received
all results. The valid options are identical to the options listed for ::ldap::searchInit.
An example of a search expression is
set filterString "|(cn=Linus*)(sn=Torvalds*)"
The return value of the command is a list of nested dictionaries. The first level keys are object
identifiers (DNs), second levels keys are attribute names. In other words, it is in the form
{dn1 {attr1 {val11 val12 ...} attr2 {val21...} ...}} {dn2 {a1 {v11 ...} ...}} ...
::ldap::searchInit handle baseObject filterString attributes options
This command initiates a LDAP search below the baseObject tree using a complex LDAP search
expression filterString. The search gets the specified attributes of all matching objects (DNs).
The command itself just starts the search, to retrieve the actual results, use ::ldap::searchNext.
A search can be terminated at any time by ::ldap::searchEnd. This informs the server that no
further results should be sent by sending and ABANDON message and cleans up the internal state of
the search. Only one ::ldap::search can be active at a given time, this includes the
introspection commands ::ldap::info saslmechanisms, ldap::info control and ldap::info extensions,
which invoke a search internally. Error responses from the server due to wrong arguments or
similar things are returned with the first ::ldap::searchNext call and should be checked and
dealed with there. If the list of requested attributes is empty all attributes will be returned.
The parameter options specifies the options to be used in the search, and has the following
format:
{-option1 value1 -option2 value2 ... }
Following options are available:
-scope base one sub
Control the scope of the search to be one of base, one, or sub, to specify a base
object, one-level or subtree search. The default is sub.
-derefaliases never search find always
Control how aliases dereferencing is done. Should be one of never, always, search, or
find to specify that aliases are never dereferenced, always dereferenced, dereferenced
when searching, or dereferenced only when locating the base object for the search. The
default is to never dereference aliases.
-sizelimit num
Determines the maximum number of entries to return in a search. If specified as 0 no limit
is enforced. The server may enforce a configuration dependent sizelimit, which may be lower
than the one given by this option. The default is 0, no limit.
-timelimit seconds
Asks the server to use a timelimit of seconds for the search. Zero means no limit. The
default is 0, no limit.
-attrsonly boolean
If set to 1 only the attribute names but not the values will be present in the search
result. The default is to retrieve attribute names and values.
-referencevar varname
If set the search result reference LDAPURIs, if any, are returned in the given variable.
The caller can than decide to follow those references and query other LDAP servers for
further results.
::ldap::searchNext handle
This command returns the next entry from a LDAP search initiated by ::ldap::searchInit. It returns
only after a new result is received or when no further results are available, but takes care to
keep the event loop alive. The returned entry is a list with two elements: the first is the DN of
the entry, the second is the list of attributes and values, under the format:
dn {attr1 {val11 val12 ...} attr2 {val21...} ...}
The ::ldap::searchNext command returns an empty list at the end of the search.
::ldap::searchEnd handle
This command terminates a LDAP search initiated by ::ldap::searchInit. It also cleans up the
internal state so a new search can be initiated. If the client has not yet received all results,
the client sends an ABANDON message to inform the server that no further results for the previous
search should to be sent.
::ldap::modify handle dn attrValToReplace ?attrToDelete? ?attrValToAdd?
This command modifies the object dn on the ldap server we are connected to via handle. It replaces
attributes with new values, deletes attributes, and adds new attributes with new values. All
arguments are dictionaries mapping attribute names to values. The optional arguments default to
the empty dictionary, which means that no attributes will be deleted nor added.
dictionary attrValToReplace (in)
No attributes will be changed if this argument is empty. The dictionary contains the new
attributes and their values. They replace all attributes known to the object.
dictionary attrToDelete (in)
No attributes will be deleted if this argument is empty. The dictionary values are
restrictions on the deletion. An attribute listed here will be deleted if and only if its
current value at the server matches the value specified in the dictionary, or if the value
in the dictionary is the empty string.
dictionary attrValToAdd (in)
No attributes will be added if this argument is empty. The dictionary values are the values
for the new attributes.
The command blocks until all modifications have completed. Its result is the empty string.
::ldap::modifyMulti handle dn attrValToReplace ?attrValToDelete? ?attrValToAdd?
This command modifies the object dn on the ldap server we are connected to via handle. It replaces
attributes with new values, deletes attributes, and adds new attributes with new values. All
arguments are lists with the format:
attr1 {val11 val12 ...} attr2 {val21...} ...
where each value list may be empty for deleting all attributes. The optional arguments default to empty
lists of attributes to delete and to add.
list attrValToReplace (in)
No attributes will be changed if this argument is empty. The dictionary contains the new
attributes and their values. They replace all attributes known to the object.
list attrValToDelete (in)
No attributes will be deleted if this argument is empty. If no value is specified, the
whole set of values for an attribute will be deleted.
list attrValToAdd (in)
No attributes will be added if this argument is empty.
The command blocks until all modifications have completed. Its result is the empty string.
::ldap::add handle dn attrValueTuples
This command creates a new object using the specified dn. The attributes of the new object are set
to the values in the list attrValueTuples. Multiple valuated attributes may be specified using
multiple tuples. The command blocks until the operation has completed. Its result is the empty
string.
::ldap::addMulti handle dn attrValueTuples
This command is the preferred one to create a new object using the specified dn. The attributes of
the new object are set to the values in the dictionary attrValueTuples (which is keyed by the
attribute names). Each tuple is a list containing multiple values. The command blocks until the
operation has completed. Its result is the empty string.
::ldap::delete handle dn
This command removes the object specified by dn, and all its attributes from the server. The
command blocks until the operation has completed. Its result is the empty string.
::ldap::modifyDN handle dn newrdn ?deleteOld? ?newSuperior?
This command moves or copies the object specified by dn to a new location in the tree of object.
This location is specified by newrdn, a relative designation, or by newrdn and newSuperior, a
absolute designation. The optional argument deleteOld defaults to true, i.e. a move operation. If
deleteOld is not set, then the operation will create a copy of dn in the new location. The
optional argument newSuperior defaults an empty string, meaning that the object must not be
relocated in another branch of the tree. If this argument is given, the argument deleteOld must be
specified also. The command blocks until the operation has completed. Its result is the empty
string.
::ldap::info ip handle
This command returns the IP address of the remote LDAP server the handle is connected to.
::ldap::info bound handle
This command returns 1 if a handle has successfully completed a ::ldap::bind. If no bind was done
or it failed, a 0 is returned.
::ldap::info bounduser handle
This command returns the username used in the bind operation if a handle has successfully
completed a ::ldap::bind. If no bound was done or it failed, an empty string is returned.
::ldap::info connections
This command returns all currently existing ldap connection handles.
::ldap::info tls handle
This command returns 1 if the ldap connection handle used TLS/SSL for connection via
ldap::secure_connect or completed ldap::starttls, 0 otherwise.
::ldap::info tlsstatus handle
This command returns the current security status of an TLS secured channel. The result is a list
of key-value pairs describing the connected peer (see the TLS package documentation for the
returned values). If the connection is not secured with TLS, an empty list is returned.
::ldap::info saslmechanisms handle
Return the supported SASL mechanisms advertised by the server. Only valid in a bound state
(anonymous or other).
::ldap::info control handle
Return the supported controls advertised by the server as a list of OIDs. Only valid in a bound
state. This is currently experimental and subject to change.
::ldap::info extensions extensions
Returns the supported LDAP extensions as list of OIDs. Only valid in a bound state. This is
currently experimental and subject to change.
::ldap::info whoami handle
Returns authzId for the current connection. This implements the RFC 4532 protocol extension.
EXAMPLES
A small example, extracted from the test application coming with this code.
package require ldap
# Connect, bind, add a new object, modify it in various ways
set handle [ldap::connect localhost 9009]
set dn "cn=Manager, o=University of Michigan, c=US"
set pw secret
ldap::bind $handle $dn $pw
set dn "cn=Test User,ou=People,o=University of Michigan,c=US"
ldap::add $handle $dn {
objectClass OpenLDAPperson
cn {Test User}
mail test.user@google.com
uid testuid
sn User
telephoneNumber +31415926535
telephoneNumber +27182818285
}
set dn "cn=Another User,ou=People,o=University of Michigan,c=US"
ldap::addMulti $handle $dn {
objectClass {OpenLDAPperson}
cn {{Anotther User}}
mail {test.user@google.com}
uid {testuid}
sn {User}
telephoneNumber {+31415926535 +27182818285}
}
# Replace all attributes
ldap::modify $handle $dn [list drink icetea uid JOLO]
# Add some more
ldap::modify $handle $dn {} {} [list drink water drink orangeJuice pager "+1 313 555 7671"]
# Delete
ldap::modify $handle $dn {} [list drink water pager ""]
# Move
ldap::modifyDN $handle $dn "cn=Tester"
# Kill the test object, and shut the connection down.
set dn "cn=Tester,ou=People,o=University of Michigan,c=US"
ldap::delete $handle $dn
ldap::unbind $handle
ldap::disconnect $handle
And another example, a simple query, and processing the results.
package require ldap
set handle [ldap::connect ldap.acme.com 389]
ldap::bind $handle
set results [ldap::search $handle "o=acme,dc=com" "(uid=jdoe)" {}]
foreach result $results {
foreach {object attributes} $result break
# The processing here is similar to what 'parray' does.
# I.e. finding the longest attribute name and then
# generating properly aligned output listing all attributes
# and their values.
set width 0
set sortedAttribs {}
foreach {type values} $attributes {
if {[string length $type] > $width} {
set width [string length $type]
}
lappend sortedAttribs [list $type $values]
}
puts "object='$object'"
foreach sortedAttrib $sortedAttribs {
foreach {type values} $sortedAttrib break
foreach value $values {
regsub -all "\[\x01-\x1f\]" $value ? value
puts [format " %-${width}s %s" $type $value]
}
}
puts ""
}
ldap::unbind $handle
ldap::disconnect $handle
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please
report such in the category ldap of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package and/or documentation.
When proposing code changes, please provide unified diffs, i.e the output of diff -u.
Note further that attachments are strongly preferred over inlined patches. Attachments can be made by
going to the Edit form of the ticket immediately after its creation, and then using the left-most button
in the secondary navigation bar.
KEYWORDS
directory access, internet, ldap, ldap client, protocol, rfc 2251, rfc 4511, x.500
CATEGORY
Networking
COPYRIGHT
Copyright (c) 2004 Andreas Kupries <andreas_kupries@users.sourceforge.net>
Copyright (c) 2004 Jochen Loewer <loewerj@web.de>
Copyright (c) 2006 Michael Schlenker <mic42@users.sourceforge.net>
tcllib 1.10.1 ldap(3tcl)