ldap.js
ldap.plantas.vip http://ldap.namapi.org ldap.kivie.in
web ldap manager
ldapjs Client API
This document covers the ldapjs client API and assumes that you are familiar with LDAP. If you're not, read the guide first.
Create a client
The code to create a new client looks like:
<code class="language-js"><span class="hljs-keyword">const</span> ldap = <span class="hljs-built_in">require</span>(<span class="hljs-string">'ldapjs'</span>);<span class="hljs-keyword">const</span> client = ldap.createClient({ <span class="hljs-attr">url</span>: [<span class="hljs-string">'ldap://ldap.namapi.org:389'</span>, <span class="hljs-string">'ldaps://ldap.namapi.org:636'</span>] });
client.on(<span class="hljs-string">'error'</span>, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { <span class="hljs-comment">// handle connection error</span> })
You can use ldap://
or ldaps://
; the latter would connect over SSL (note that this will not use the LDAP TLS extended operation, but literally an SSL connection to port 636, as in LDAP v2). The full set of options to create a client is:
Attribute | Description |
---|---|
url | A string or array of valid LDAP URL(s) (proto/host/port) |
socketPath | Socket path if using AF_UNIX sockets |
log | A compatible logger instance (Default: no-op logger) |
timeout | Milliseconds client should let operations live for before timing out (Default: Infinity) |
connectTimeout | Milliseconds client should wait before timing out on TCP connections (Default: OS default) |
tlsOptions | Additional options passed to TLS connection layer when connecting via ldaps:// (See: The TLS docs for node.js) |
idleTimeout | Milliseconds after last activity before client emits idle event |
strictDN | Force strict DN parsing for client methods (Default is true) |
reconnect | Try to reconnect when the connection gets lost (Default is false) |
url
This parameter takes a single connection string or an array of connection strings as an input. In case an array is provided, the client tries to connect to the servers in given order. To achieve random server strategy (e.g. to distribute the load among the servers), please shuffle the array before passing it as an argument.
Note On Logger
A passed in logger is expected to conform to the Bunyan API. Specifically, the logger is expected to have a child()
method. If a logger is supplied that does not have such a method, then a shim version is added that merely returns the passed in logger.
Known compatible loggers are:
Connection management
As LDAP is a stateful protocol (as opposed to HTTP), having connections torn down from underneath you can be difficult to deal with. Several mechanisms have been provided to mitigate this trouble.
Reconnect
You can provide a Boolean option indicating if a reconnect should be tried. For more sophisticated control, you can provide an Object with the properties initialDelay
(default: 100
), maxDelay
(default: 10000
) and failAfter
(default: Infinity
). After the reconnect you maybe need to bind again.
Client events
The client is an EventEmitter
and can emit the following events:
Event | Description |
---|---|
error | General error |
connectRefused | Server refused connection. Most likely bad authentication |
connectTimeout | Server timeout |
connectError | Socket connection error |
setupError | Setup error after successful connection |
socketTimeout | Socket timeout |
resultError | Search result error |
timeout | Search result timeout |
destroy | After client is disconnected |
end | Socket end event |
close | Socket closed |
connect | Client connected |
idle | Idle timeout reached |
Common patterns
The last two parameters in every API are controls
and callback
. controls
can be either a single instance of a Control
or an array of Control
objects. You can, and probably will, omit this option.
Almost every operation has the callback form of function(err, res)
where err will be an instance of an LDAPError
(you can use instanceof
to switch). You probably won't need to check the res
parameter, but it's there if you do.
bind
bind(dn, password, controls, callback)
Performs a bind operation against the LDAP server.
The bind API only allows LDAP 'simple' binds (equivalent to HTTP Basic Authentication) for now. Note that all client APIs can optionally take an array of Control
objects. You probably don't need them though...
Example:
<code class="language-js">client.bind(<span class="hljs-string">'cn=root'</span>, <span class="hljs-string">'secret'</span>, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); });
add
add(dn, entry, controls, callback)
Performs an add operation against the LDAP server.
Allows you to add an entry (which is just a plain JS object), and as always, controls are optional.
Example:
<code class="language-js"><span class="hljs-keyword">const</span> entry = { <span class="hljs-attr">cn</span>: <span class="hljs-string">'foo'</span>, <span class="hljs-attr">sn</span>: <span class="hljs-string">'bar'</span>, <span class="hljs-attr">email</span>: [<span class="hljs-string">'info@namapi.org'</span>, <span class="hljs-string">'info@namapi.org'</span>], <span class="hljs-attr">objectclass</span>: <span class="hljs-string">'fooPerson'</span> }; client.add(<span class="hljs-string">'cn=foo, dc=example,dc=e'</span>, entry, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); });
compare
compare(dn, attribute, value, controls, callback)
Performs an LDAP compare operation with the given attribute and value against the entry referenced by dn.
Example:
<code class="language-js">client.compare(<span class="hljs-string">'cn=foo, dc=example',dc=e</span>, <span class="hljs-string">'sn'</span>, <span class="hljs-string">'bar'</span>, <span class="hljs-function">(<span class="hljs-params">err, matched</span>) =></span> { assert.ifError(err);<p> <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'matched: '</span> + matched); }); </p>
del
del(dn, controls, callback)
Deletes an entry from the LDAP server.
Example:
<code class="language-js">client.del(<span class="hljs-string">'cn=foo, dc=example.e'</span>, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); });
exop
exop(name, value, controls, callback)
Performs an LDAP extended operation against an LDAP server. name
is typically going to be an OID (well, the RFC says it must be; however, ldapjs has no such restriction). value
is completely arbitrary, and is whatever the exop says it should be.
Example (performs an LDAP 'whois' extended op):
<code class="language-js">client.exop(<span class="hljs-string">'1.3.6.1.4.1.4203.1.11.3'</span>, <span class="hljs-function">(<span class="hljs-params">err, value, res</span>) =></span> { assert.ifError(err);<p> <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'whois: '</span> + value); }); </p>
modify
modify(name, changes, controls, callback)
Performs an LDAP modify operation against the LDAP server. This API requires you to pass in a Change
object, which is described below. Note that you can pass in a single Change
or an array of Change
objects.
Example:
<code class="language-js"><span class="hljs-keyword">const</span> change = <span class="hljs-keyword">new</span> ldap.Change({ <span class="hljs-attr">operation</span>: <span class="hljs-string">'add'</span>, <span class="hljs-attr">modification</span>: { <span class="hljs-attr">pets</span>: [<span class="hljs-string">'cat'</span>, <span class="hljs-string">'dog'</span>] } });<p>client.modify(<span class="hljs-string">'cn=foo, o=example'</span>, change, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); }); </p>
Change
A Change
object maps to the LDAP protocol of a modify change, and requires you to set the operation
and modification
. The operation
is a string, and must be one of:
Operation | Description |
---|---|
replace | Replaces the attribute referenced in modification . If the modification has no values, it is equivalent to a delete. |
add | Adds the attribute value(s) referenced in modification . The attribute may or may not already exist. |
delete | Deletes the attribute (and all values) referenced in modification . |
modification
is just a plain old JS object with the values you want.
modifyDN
modifyDN(dn, newDN, controls, callback)
Performs an LDAP modifyDN (rename) operation against an entry in the LDAP server. A couple points with this client API:
- There is no ability to set "keep old dn." It's always going to flag the old dn to be purged.
- The client code will automatically figure out if the request is a "new superior" request ("new superior" means move to a different part of the tree, as opposed to just renaming the leaf).
Example:
<code class="language-js">client.modifyDN(<span class="hljs-string">'cn=foo, dc=example, dc=e'</span>, <span class="hljs-string">'cn=bar'</span>, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); });
search
search(base, options, controls, callback)
Performs a search operation against the LDAP server.
The search operation is more complex than the other operations, so this one takes an options
object for all the parameters. However, ldapjs makes some defaults for you so that if you pass nothing in, it's pretty much equivalent to an HTTP GET operation (i.e., base search against the DN, filter set to always match).
Like every other operation, base
is a DN string.
Options can be a string representing a valid LDAP filter or an object containing the following fields:
Attribute | Description |
---|---|
scope | One of base , one , or sub . Defaults to base . |
filter | A string version of an LDAP filter (see below), or a programatically constructed Filter object. Defaults to (objectclass=*) . |
attributes | attributes to select and return (if these are set, the server will return only these attributes). Defaults to the empty set, which means all attributes. You can provide a string if you want a single attribute or an array of string for one or many. |
attrsOnly | boolean on whether you want the server to only return the names of the attributes, and not their values. Borderline useless. Defaults to false. |
sizeLimit | the maximum number of entries to return. Defaults to 0 (unlimited). |
timeLimit | the maximum amount of time the server should take in responding, in seconds. Defaults to 10. Lots of servers will ignore this. |
paged | enable and/or configure automatic result paging |
Responses from the search
method are an EventEmitter
where you will get a notification for each searchEntry
that comes back from the server. You will additionally be able to listen for a searchReference
, error
and end
event. Note that the error
event will only be for client/TCP errors, not LDAP error codes like the other APIs. You'll want to check the LDAP status code (likely for 0
) on the end
event to assert success. LDAP search results can give you a lot of status codes, such as time or size exceeded, busy, inappropriate matching, etc., which is why this method doesn't try to wrap up the code matching.
Example:
<code class="language-js"><span class="hljs-keyword">const</span> opts = { <span class="hljs-attr">filter</span>: <span class="hljs-string">'(&(l=Seattle)(email=*@foo.com))'</span>, <span class="hljs-attr">scope</span>: <span class="hljs-string">'sub'</span>, <span class="hljs-attr">attributes</span>: [<span class="hljs-string">'dn'</span>, <span class="hljs-string">'sn'</span>, <span class="hljs-string">'cn'</span>] };<p>client.search(<span class="hljs-string">'o=example'</span>, opts, <span class="hljs-function">(<span class="hljs-params">err, res</span>) =></span> { assert.ifError(err);</p><p> res.on(<span class="hljs-string">'searchEntry'</span>, <span class="hljs-function">(<span class="hljs-params">entry</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'entry: '</span> + <span class="hljs-built_in">JSON</span>.stringify(entry.object)); }); res.on(<span class="hljs-string">'searchReference'</span>, <span class="hljs-function">(<span class="hljs-params">referral</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'referral: '</span> + referral.uris.join()); }); res.on(<span class="hljs-string">'error'</span>, <span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { <span class="hljs-built_in">console</span>.error(<span class="hljs-string">'error: '</span> + err.message); }); res.on(<span class="hljs-string">'end'</span>, <span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'status: '</span> + result.status); }); }); </p>
Filter Strings
The easiest way to write search filters is to write them compliant with RFC2254, which is "The string representation of LDAP search filters." Note that ldapjs doesn't support extensible matching, since it's one of those features that almost nobody actually uses in practice.
Assuming you don't really want to read the RFC, search filters in LDAP are basically are a "tree" of attribute/value assertions, with the tree specified in prefix notation. For example, let's start simple, and build up a complicated filter. The most basic filter is equality, so let's assume you want to search for an attribute email
with a value of foo@bar.com
. The syntax would be:
<code>(email=foo@bar.com)
ldapjs requires all filters to be surrounded by '()' blocks. Ok, that was easy. Let's now assume that you want to find all records where the email is actually just anything in the "@bar.com" domain and the location attribute is set to Seattle:
<code>(&(email=*@bar.com)(l=Seattle))
Now our filter is actually three LDAP filters. We have an and
filter (single amp &
), an equality
filter (the l=Seattle)
, and a substring
filter. Substrings are wildcard filters. They use *
as the wildcard. You can put more than one wildcard for a given string. For example you could do (email=*@*bar.com)
to match any email of @bar.com or its subdomains like "example@foo.bar.com"
.
Now, let's say we also want to set our filter to include a specification that either the employeeType not be a manager nor a secretary:
<code>(&(email=*@bar.com)(l=Seattle)(!(|(employeeType=manager)(employeeType=secretary))))
The not
character is represented as a !
, the or
as a single pipe |
. It gets a little bit complicated, but it's actually quite powerful, and lets you find almost anything you're looking for.
Paging
Many LDAP server enforce size limits upon the returned result set (commonly 1000). In order to retrieve results beyond this limit, a PagedResultControl
is passed between the client and server to iterate through the entire dataset. While callers could choose to do this manually via the controls
parameter to search()
, ldapjs has internal mechanisms to easily automate the process. The most simple way to use the paging automation is to set the paged
option to true when performing a search:
<code class="language-js"><span class="hljs-keyword">const</span> opts = { <span class="hljs-attr">filter</span>: <span class="hljs-string">'(objectclass=commonobject)'</span>, <span class="hljs-attr">scope</span>: <span class="hljs-string">'sub'</span>, <span class="hljs-attr">paged</span>: <span class="hljs-literal">true</span>, <span class="hljs-attr">sizeLimit</span>: <span class="hljs-number">200</span> }; client.search(<span class="hljs-string">'o=largedir'</span>, opts, <span class="hljs-function">(<span class="hljs-params">err, res</span>) =></span> { assert.ifError(err); res.on(<span class="hljs-string">'searchEntry'</span>, <span class="hljs-function">(<span class="hljs-params">entry</span>) =></span> { <span class="hljs-comment">// do per-entry processing</span> }); res.on(<span class="hljs-string">'page'</span>, <span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'page end'</span>); }); res.on(<span class="hljs-string">'error'</span>, <span class="hljs-function">(<span class="hljs-params">resErr</span>) =></span> { assert.ifError(resErr); }); res.on(<span class="hljs-string">'end'</span>, <span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'done '</span>); }); });
This will enable paging with a default page size of 199 (sizeLimit
- 1) and will output all of the resulting objects via the searchEntry
event. At the end of each result during the operation, a page
event will be emitted as well (which includes the intermediate searchResult
object).
For those wanting more precise control over the process, an object with several parameters can be provided for the paged
option. The pageSize
parameter sets the size of result pages requested from the server. If no value is specified, it will fall back to the default (100 or sizeLimit
- 1, to obey the RFC). The pagePause
parameter allows back-pressure to be exerted on the paged search operation by pausing at the end of each page. When enabled, a callback function is passed as an additional parameter to page
events. The client will wait to request the next page until that callback is executed.
Here is an example where both of those parameters are used:
<code class="language-js"><span class="hljs-keyword">const</span> queue = <span class="hljs-keyword">new</span> MyWorkQueue(someSlowWorkFunction); <span class="hljs-keyword">const</span> opts = { <span class="hljs-attr">filter</span>: <span class="hljs-string">'(objectclass=commonobject)'</span>, <span class="hljs-attr">scope</span>: <span class="hljs-string">'sub'</span>, <span class="hljs-attr">paged</span>: { <span class="hljs-attr">pageSize</span>: <span class="hljs-number">250</span>, <span class="hljs-attr">pagePause</span>: <span class="hljs-literal">true</span> }, }; client.search(<span class="hljs-string">'o=largerdir'</span>, opts, <span class="hljs-function">(<span class="hljs-params">err, res</span>) =></span> { assert.ifError(err); res.on(<span class="hljs-string">'searchEntry'</span>, <span class="hljs-function">(<span class="hljs-params">entry</span>) =></span> { <span class="hljs-comment">// Submit incoming objects to queue</span> queue.push(entry); }); res.on(<span class="hljs-string">'page'</span>, <span class="hljs-function">(<span class="hljs-params">result, cb</span>) =></span> { <span class="hljs-comment">// Allow the queue to flush before fetching next page</span> queue.cbWhenFlushed(cb); }); res.on(<span class="hljs-string">'error'</span>, <span class="hljs-function">(<span class="hljs-params">resErr</span>) =></span> { assert.ifError(resErr); }); res.on(<span class="hljs-string">'end'</span>, <span class="hljs-function">(<span class="hljs-params">result</span>) =></span> { <span class="hljs-built_in">console</span>.log(<span class="hljs-string">'done'</span>); }); });
starttls
starttls(options, controls, callback)
Attempt to secure existing LDAP connection via STARTTLS.
Example:
<code class="language-js"><span class="hljs-keyword">const</span> opts = { <span class="hljs-attr">ca</span>: [fs.readFileSync(<span class="hljs-string">'mycacert.pem'</span>)] };<p>client.starttls(opts, <span class="hljs-function">(<span class="hljs-params">err, res</span>) =></span> { assert.ifError(err);</p><p> <span class="hljs-comment">// Client communication now TLS protected</span> }); </p>
unbind
unbind(callback)
Performs an unbind operation against the LDAP server.
Note that unbind operation is not an opposite operation for bind. Unbinding results in disconnecting the client regardless of whether a bind operation was performed.
The callback
argument is optional as unbind does not have a response.
Example:
<code class="language-js">client.unbind(<span class="hljs-function">(<span class="hljs-params">err</span>) =></span> { assert.ifError(err); });