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Server API | ldapjs | wiki-tables |
ldapjs Server API
This document covers the ldapjs server API and assumes that you are familiar with LDAP. If you're not, read the guide first.
Create a server
The code to create a new server looks like:
var server = ldap.createServer();
The full list of options is:
||log||You can optionally pass in a Bunyan compatible logger instance the client will use to acquire a child logger.|| ||certificate||A PEM-encoded X.509 certificate; will cause this server to run in TLS mode.|| ||key||A PEM-encoded private key that corresponds to certificate for SSL.||
Note On Logger
The passed in logger is expected to conform to the Log4j standard API. Internally, abstract-logging is used to implement the interface. As a result, no log messages will be generated unless an external logger is supplied.
Known compatible loggers are:
Properties on the server object
maxConnections
Set this property to reject connections when the server's connection count gets high.
connections (getter only) - DEPRECATED
The number of concurrent connections on the server. This property is deprecated, please use server.getConnections() instead.
url
Returns the fully qualified URL this server is listening on. For example:
ldaps://10.1.2.3:1636
. If you haven't yet called listen
, it will always
return ldap://localhost:389
.
Event: 'close'
function() {}
Emitted when the server closes.
Listening for requests
The LDAP server API wraps up and mirrors the node.js server.listen
family of
APIs.
After calling listen
, the property url
on the server object itself will be
available.
Example:
server.listen(389, '127.0.0.1', function() {
console.log('LDAP server listening at: ' + server.url);
});
Port and Host
listen(port, [host], [callback])
Begin accepting connections on the specified port and host. If the host is omitted, the server will accept connections directed to any IPv4 address (INADDR_ANY).
This function is asynchronous. The last parameter callback will be called when the server has been bound.
Unix Domain Socket
listen(path, [callback])
Start a UNIX socket server listening for connections on the given path.
This function is asynchronous. The last parameter callback will be called when the server has been bound.
File descriptor
listenFD(fd)
Start a server listening for connections on the given file descriptor.
This file descriptor must have already had the bind(2)
and listen(2)
system
calls invoked on it. Additionally, it must be set non-blocking; try
fcntl(fd, F_SETFL, O_NONBLOCK)
.
Inspecting server state
server.getConnections(callback)
The LDAP server API mirrors the Node.js server.getConnections
API. Callback
should take two arguments err and count.
Routes
The LDAP server API is meant to be the LDAP-equivalent of the express/restify
paradigm of programming. Essentially every method is of the form
OP(req, res, next)
where OP is one of bind, add, del, etc. You can chain
handlers together by calling next()
and ordering your functions in the
definition of the route. For example:
function authorize(req, res, next) {
if (!req.connection.ldap.bindDN.equals('cn=root'))
return next(new ldap.InsufficientAccessRightsError());
return next();
}
server.search('o=example', authorize, function(req, res, next) { ... });
Note that ldapjs is also slightly different, since it's often going to be backed to a DB-like entity, in that it also has an API where you can pass in a 'backend' object. This is necessary if there are persistent connection pools, caching, etc. that need to be placed in an object.
For example ldapjs-riak is a complete implementation of the LDAP protocol over Riak. Getting an LDAP server up with riak looks like:
var ldap = require('ldapjs');
var ldapRiak = require('ldapjs-riak');
var server = ldap.createServer();
var backend = ldapRiak.createBackend({
"host": "localhost",
"port": 8098,
"bucket": "example",
"indexes": ["l", "cn"],
"uniqueIndexes": ["uid"],
"numConnections": 5
});
server.add("o=example",
backend,
backend.add());
...
The first parameter to an ldapjs route is always the point in the
tree to mount the handler chain at. The second argument is optionally a
backend object. After that you can pass in an arbitrary combination of
functions in the form f(req, res, next)
or arrays of functions of the same
signature (ldapjs will unroll them).
Unlike HTTP, LDAP operations do not have a heterogeneous wire format, so each
operation requires specific methods/fields on the request/response
objects. However, there is a .use()
method availabe, similar to
that on express/connect, allowing you to chain up "middleware":
server.use(function(req, res, next) {
console.log('hello world');
return next();
});
Common Request Elements
All request objects have the dn
getter on it, which is "context-sensitive"
and returns the point in the tree that the operation wants to operate on. The
LDAP protocol itself sadly doesn't define operations this way, and has a unique
name for just about every op. So, ldapjs calls it dn
. The DN object itself
is documented at DN.
All requests have an optional array of Control
objects. Control
will have
the properties type
(string), criticality
(boolean), and optionally, a
string value
.
All request objects will have a connection
object, which is the net.Socket
associated to this request. Off the connection
object is an ldap
object.
The most important property to pay attention to is the bindDN
property
which will be an instance of an ldap.DN
object. This is what the client
authenticated as on this connection. If the client didn't bind, then a DN object
will be there defaulted to cn=anonymous
.
Additionally, request will have a logId
parameter you can use to uniquely
identify the request/connection pair in logs (includes the LDAP messageID).
Common Response Elements
All response objects will have an end
method on them. By default, calling
res.end()
with no arguments will return SUCCESS (0x00) to the client
(with the exception of compare
which will return COMPARE_TRUE (0x06)). You
can pass in a status code to the end()
method to return an alternate status
code.
However, it's more common/easier to use the return next(new LDAPError())
pattern, since ldapjs will fill in the extra LDAPResult fields like matchedDN
and error message for you.
Errors
ldapjs includes an exception hierarchy that directly corresponds to the RFC list
of error codes. The complete list is documented in errors. But
the paradigm is something defined like CONSTRAINT_VIOLATION in the RFC would be
ConstraintViolationError
in ldapjs. Upon calling next(new LDAPError())
,
ldapjs will stop calling your handler chain. For example:
server.search('o=example',
function(req, res, next) { return next(); },
function(req, res, next) { return next(new ldap.OperationsError()); },
function(req, res, next) { res.end(); }
);
In the code snipped above, the third handler would never get invoked.
Bind
Adds a mount in the tree to perform LDAP binds with. Example:
server.bind('ou=people, o=example', function(req, res, next) {
console.log('bind DN: ' + req.dn.toString());
console.log('bind PW: ' + req.credentials);
res.end();
});
BindRequest
BindRequest objects have the following properties:
version
The LDAP protocol version the client is requesting to run this connection on. Note that ldapjs only supports LDAP version 3.
name
The DN the client is attempting to bind as (note this is the same as the dn
property).
authentication
The method of authentication. Right now only simple
is supported.
credentials
The credentials to go with the name/authentication
pair. For simple
, this
will be the plain-text password.
BindResponse
No extra methods above an LDAPResult
API call.
Add
Adds a mount in the tree to perform LDAP adds with.
server.add('ou=people, o=example', function(req, res, next) {
console.log('DN: ' + req.dn.toString());
console.log('Entry attributes: ' + req.toObject().attributes);
res.end();
});
AddRequest
AddRequest objects have the following properties:
entry
The DN the client is attempting to add (this is the same as the dn
property).
attributes
The set of attributes in this entry. This will be an array of
Attribute
objects (which have a type and an array of values). This directly
maps to how the request came in off the wire. It's likely you'll want to use
toObject()
and iterate that way, since that will transform an AddRequest into
a standard JavaScript object.
toObject()
This operation will return a plain JavaScript object from the request that looks like:
{
dn: 'cn=foo, o=example', // string, not DN object
attributes: {
cn: ['foo'],
sn: ['bar'],
objectclass: ['person', 'top']
}
}
AddResponse
No extra methods above an LDAPResult
API call.
Search
Adds a handler for the LDAP search operation.
server.search('o=example', function(req, res, next) {
console.log('base object: ' + req.dn.toString());
console.log('scope: ' + req.scope);
console.log('filter: ' + req.filter.toString());
res.end();
});
SearchRequest
SearchRequest objects have the following properties:
baseObject
The DN the client is attempting to start the search at (equivalent to dn
).
scope
(string) one of:
- base
- one
- sub
derefAliases
An integer (defined in the LDAP protocol). Defaults to '0' (meaning never deref).
sizeLimit
The number of entries to return. Defaults to '0' (unlimited). ldapjs doesn't currently automatically enforce this, but probably will at some point.
timeLimit
Maximum amount of time the server should take in sending search entries. Defaults to '0' (unlimited).
typesOnly
Whether to return only the names of attributes, and not the values. Defaults to 'false'. ldapjs will take care of this for you.
filter
The filter object that the client requested. Notably this has
a matches()
method on it that you can leverage. For an example of
introspecting a filter, take a look at the ldapjs-riak source.
attributes
An optional list of attributes to restrict the returned result sets to. ldapjs will automatically handle this for you.
SearchResponse
send(entry)
Allows you to send a SearchEntry
object. You do not need to
explicitly pass in a SearchEntry
object, and can instead just send a plain
JavaScript object that matches the format used from AddRequest.toObject()
.
server.search('o=example', function(req, res, next) {
var obj = {
dn: 'o=example',
attributes: {
objectclass: ['top', 'organization'],
o: ['example']
}
};
if (req.filter.matches(obj))
res.send(obj)
res.end();
});
modify
Allows you to handle an LDAP modify operation.
server.modify('o=example', function(req, res, next) {
console.log('DN: ' + req.dn.toString());
console.log('changes:');
req.changes.forEach(function(c) {
console.log(' operation: ' + c.operation);
console.log(' modification: ' + c.modification.toString());
});
res.end();
});
ModifyRequest
ModifyRequest objects have the following properties:
object
The DN the client is attempting to update (this is the same as the dn
property).
changes
An array of Change
objects the client is attempting to perform. See below for
details on the Change
object.
Change
The Change
object will have the following properties:
operation
A string, and will be one of: 'add', 'delete', or 'replace'.
modification
Will be an Attribute
object, which will have a 'type' (string) field, and
'vals', which will be an array of string values.
ModifyResponse
No extra methods above an LDAPResult
API call.
del
Allows you to handle an LDAP delete operation.
server.del('o=example', function(req, res, next) {
console.log('DN: ' + req.dn.toString());
res.end();
});
DeleteRequest
entry
The DN the client is attempting to delete (this is the same as the dn
property).
DeleteResponse
No extra methods above an LDAPResult
API call.
compare
Allows you to handle an LDAP compare operation.
server.compare('o=example', function(req, res, next) {
console.log('DN: ' + req.dn.toString());
console.log('attribute name: ' + req.attribute);
console.log('attribute value: ' + req.value);
res.end(req.value === 'foo');
});
CompareRequest
entry
The DN the client is attempting to compare (this is the same as the dn
property).
attribute
The string name of the attribute to compare values of.
value
The string value of the attribute to compare.
CompareResponse
The end()
method for compare takes a boolean, as opposed to a numeric code
(you can still pass in a numeric LDAP status code if you want). Beyond
that, there are no extra methods above an LDAPResult
API call.
modifyDN
Allows you to handle an LDAP modifyDN operation.
server.modifyDN('o=example', function(req, res, next) {
console.log('DN: ' + req.dn.toString());
console.log('new RDN: ' + req.newRdn.toString());
console.log('deleteOldRDN: ' + req.deleteOldRdn);
console.log('new superior: ' +
(req.newSuperior ? req.newSuperior.toString() : ''));
res.end();
});
ModifyDNRequest
entry
The DN the client is attempting to rename (this is the same as the dn
property).
newRdn
The leaf RDN the client wants to rename this entry to. This will be a DN object.
deleteOldRdn
Whether or not to delete the old RDN (i.e., rename vs copy). Defaults to 'true'.
newSuperior
Optional (DN). If the modifyDN operation wishes to relocate the entry in the
tree, the newSuperior
field will contain the new parent.
ModifyDNResponse
No extra methods above an LDAPResult
API call.
exop
Allows you to handle an LDAP extended operation. Extended operations are pretty much arbitrary extensions, by definition. Typically the extended 'name' is an OID, but ldapjs makes no such restrictions; it just needs to be a string. Unlike the other operations, extended operations don't map to any location in the tree, so routing here will be exact match, as opposed to subtree.
// LDAP whoami
server.exop('1.3.6.1.4.1.4203.1.11.3', function(req, res, next) {
console.log('name: ' + req.name);
console.log('value: ' + req.value);
res.value = 'u:xxyyz@EXAMPLE.NET';
res.end();
return next();
});
ExtendedRequest
name
Will always be a match to the route-defined name. Clients must include this in their requests.
value
Optional string. The arbitrary blob the client sends for this extended operation.
ExtendedResponse
name
The name of the extended operation. ldapjs will automatically set this.
value
The arbitrary (string) value to send back as part of the response.
unbind
ldapjs by default provides an unbind handler that just disconnects the client and cleans up any internals (in ldapjs core). You can override this handler if you need to clean up any items in your backend, or perform any other cleanup tasks you need to.
server.unbind(function(req, res, next) {
res.end();
});
Note that the LDAP unbind operation actually doesn't send any response (by
definition in the RFC), so the UnbindResponse is really just a stub that
ultimately calls net.Socket.end()
for you. There are no properties available
on either the request or response objects, except, of course, for end()
on the
response.