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ldap interview questions

Top ldap frequently asked interview questions

How do I clone an OpenLDAP database

I know this is more like a serverfault question than a stackoverflow question, but since serverfault isn't up yet, here I go:

I'm supposed to move an application from one redhat server to another, and without very good knowledge of the internal workings of the application, how would I move the OpenLDAP database from the one machine to the other, with schemas and all.

What files would I need to copy over? I believe the setup is pretty standard.


Source: (StackOverflow)

ldap nested group membership

Is it possible to create an LDAP query which will return (or check for) users in a nested group? e.g. UserA is a member of GroupA, and GroupA is a member of GroupB. I want a query on GroupB to return that UserA is a member. LDAP only. The server is Active Directory.


Source: (StackOverflow)

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How to write LDAP query to test if user is member of a group?

I want to write an LDAP query which tests whether a user (sAMAccountName) is a member of a particular group. Is it possible to do that so that I get either 0 or 1 result records?

I guess I can get all groups for the user and test each one for a match but I was wondering if I could pack it into one LDAP expression.

Any ideas?

Thanks


Source: (StackOverflow)

svnserve with LDAP

I would like to know how to setup an SVN repository with LDAP authentication. I do not want to use Apache DAV though.


Source: (StackOverflow)

Authenticating in PHP using LDAP through Active Directory

I'm looking for a way to authenticate users through LDAP with PHP (with Active Directory being the provider). Ideally, it should be able to run on IIS 7 (adLDAP does it on Apache). Anyone had done anything similar, with success?

  • Edit: I'd prefer a library/class with code that's ready to go... It'd be silly to invent the wheel when someone has already done so.

Source: (StackOverflow)

What is LDAP used for?

I know that LDAP is used to provide some information and to help facilitate authorization.

But what are the other usages of LDAP?


Source: (StackOverflow)

What are the differences between LDAP and Active Directory?

What are the differences between LDAP and Active Directory?


Source: (StackOverflow)

What are CN, OU, DC in an LDAP search?

I have a search query in LDAP like this. What exactly does this query mean?

("CN=Dev-India,OU=Distribution Groups,DC=gp,DC=gl,DC=google,DC=com");

Source: (StackOverflow)

Python: can't install python-ldap

When I run the following command:

sudo pip install python-ldap

I get this error:

In file included from Modules/LDAPObject.c:9:

Modules/errors.h:8: fatal error: lber.h: No such file or directory

Any ideas how to fix this?


Source: (StackOverflow)

How to PHP ldap_search() to get user OU if I don't know the OU for base DN

I have an Active-Directory structure where User objects reside in OU for example, IT, Technical, HR, Accounts etc.. I want to write a PHP script that authenticates the user with AD and depending on their Group to provide the aproperiate web services.

ldap_search() requires base DN. I tried to search with

ldap_search($ldap, "dc=country,dc=company,dc=co,dc=uk", "(samaccountname=$username)", array("memberof"));

but PHP gives "Operation Error". If instead i specify the OU

ldap_search($ldap, "ou=sales,dc=country,dc=company,dc=co,dc=uk", "(samaccountname=jake)", array("memberof"));

then the search is ok.

Is there a wildcard I can use?

On a side note, should user objects be in OU at all? Because I am the noob who moved them inside in the first place!

EDIT: With credits to JPBlanc for guiding me in the right direction and http://blog.redbranch.net/?p=76

The solution is to add 2 lines between connect and bind.

ldap_connect(..)
ldap_set_option ($ldap, LDAP_OPT_REFERRALS, 0);
ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_bind(..)

Thanks =)

EDIT 2 - Fullcode:

<?php

namespace ldap;

abstract class AuthStatus
{
    const FAIL = "Authentication failed";
    const OK = "Authentication OK";
    const SERVER_FAIL = "Unable to connect to LDAP server";
    const ANONYMOUS = "Anonymous log on";
}

// The LDAP server
class LDAP
{
    private $server = "127.0.0.1";
    private $domain = "localhost";
    private $admin = "admin";
    private $password = "";

    public function __construct($server, $domain, $admin = "", $password = "")
    {
        $this->server = $server;
        $this->domain = $domain;
        $this->admin = $admin;
        $this->password = $password;
    }

    // Authenticate the against server the domain\username and password combination.
    public function authenticate($user)
    {
        $user->auth_status = AuthStatus::FAIL;

        $ldap = ldap_connect($this->server) or $user->auth_status = AuthStatus::SERVER_FAIL;
        ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0);
        ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3);
        $ldapbind = ldap_bind($ldap, $user->username."@".$this->domain, $user->password);

        if($ldapbind)
        {
            if(empty($user->password))
            {
                $user->auth_status = AuthStatus::ANONYMOUS;
            }
            else
            {
                $result = $user->auth_status = AuthStatus::OK;

                $this->_get_user_info($ldap, $user);
            }
        }
        else
        {
            $result = $user->auth_status = AuthStatus::FAIL;
        }

        ldap_close($ldap);
    }

    // Get an array of users or return false on error
    public function get_users()
    {       
        if(!($ldap = ldap_connect($this->server))) return false;

        ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0);
        ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3);
        $ldapbind = ldap_bind($ldap, $this->admin."@".$this->domain, $this->password);

        $dc = explode(".", $this->domain);
        $base_dn = "";
        foreach($dc as $_dc) $base_dn .= "dc=".$_dc.",";
        $base_dn = substr($base_dn, 0, -1);
        $sr=ldap_search($ldap, $base_dn, "(&(objectClass=user)(objectCategory=person)(|(mail=*)(telephonenumber=*))(!(userAccountControl:1.2.840.113556.1.4.803:=2)))", array("cn", "dn", "memberof", "mail", "telephonenumber", "othertelephone", "mobile", "ipphone", "department", "title"));
        $info = ldap_get_entries($ldap, $sr);

        for($i = 0; $i < $info["count"]; $i++)
        {
            $users[$i]["name"] = $info[$i]["cn"][0];
            $users[$i]["mail"] = $info[$i]["mail"][0];
            $users[$i]["mobile"] = $info[$i]["mobile"][0];
            $users[$i]["skype"] = $info[$i]["ipphone"][0];
            $users[$i]["telephone"] = $info[$i]["telephonenumber"][0];
            $users[$i]["department"] = $info[$i]["department"][0];
            $users[$i]["title"] = $info[$i]["title"][0];

            for($t = 0; $t < $info[$i]["othertelephone"]["count"]; $t++)
                $users[$i]["othertelephone"][$t] = $info[$i]["othertelephone"][$t];

            // set to empty array
            if(!is_array($users[$i]["othertelephone"])) $users[$i]["othertelephone"] = Array();
        }

        return $users;
    }

    private function _get_user_info($ldap, $user)
    {
        $dc = explode(".", $this->domain);

        $base_dn = "";
        foreach($dc as $_dc) $base_dn .= "dc=".$_dc.",";

        $base_dn = substr($base_dn, 0, -1);

        $sr=ldap_search($ldap, $base_dn, "(&(objectClass=user)(objectCategory=person)(samaccountname=".$user->username."))", array("cn", "dn", "memberof", "mail", "telephonenumber", "othertelephone", "mobile", "ipphone", "department", "title"));
        $info = ldap_get_entries($ldap, $sr);

        $user->groups = Array();
        for($i = 0; $i < $info[0]["memberof"]["count"]; $i++)
            array_push($user->groups, $info[0]["memberof"][$i]);

        $user->name = $info[0]["cn"][0];
        $user->dn = $info[0]["dn"];
        $user->mail = $info[0]["mail"][0];
        $user->telephone = $info[0]["telephonenumber"][0];
        $user->mobile = $info[0]["mobile"][0];
        $user->skype = $info[0]["ipphone"][0];
        $user->department = $info[0]["department"][0];
        $user->title = $info[0]["title"][0];

        for($t = 0; $t < $info[$i]["othertelephone"]["count"]; $t++)
                $user->other_telephone[$t] = $info[$i]["othertelephone"][$t];

        if(!is_array($user->other_telephone[$t])) $user->other_telephone[$t] = Array();
    }
}

class User
{
    var $auth_status = AuthStatus::FAIL;
    var $username = "Anonymous";
    var $password = "";

    var $groups = Array();
    var $dn = "";
    var $name = "";
    var $mail = "";
    var $telephone = "";
    var $other_telephone = Array();
    var $mobile = "";
    var $skype = "";
    var $department = "";
    var $title = "";

    public function __construct($username, $password)
    {       
        $this->auth_status = AuthStatus::FAIL;
        $this->username = $username;
        $this->password = $password;
    }

    public function get_auth_status()
    {
        return $this->auth_status;
    }
 }
?>

Usage:

$ldap = new ldap\LDAP("192.168.1.123", "company.com", "admin", "mypassword");
$users = $ldap->get_users();

Source: (StackOverflow)

Is LDAP obsolete?

Should I spend time implementing LDAP for authentication in my web application(php)? Is it a 'dead' technology?

If it is what are the alternatives? and, if its not, what are good resources i can use? (books, tutorials)


Source: (StackOverflow)

How to save the LDAP SSL Certificate from OpenSSL

I wanted the SSL Certificate of my LDAP Server which is Novell eDirectory. I have used openssl to connect to ldap to view the certificate

openssl s_client -connect 192.168.1.225:636

it is just printing the certificate how can i save this to some certificate format file?

Thanks and regards,

Sunny.


Source: (StackOverflow)

Authenticating against active directory using python + ldap

How do I authenticate against AD using Python + LDAP. I'm currently using the python-ldap library and all it is producing is tears.

I can't even bind to perform a simple query:

import sys
import ldap


Server = "ldap://my-ldap-server"
DN, Secret, un = sys.argv[1:4]

Base = "dc=mydomain,dc=co,dc=uk"
Scope = ldap.SCOPE_SUBTREE
Filter = "(&(objectClass=user)(sAMAccountName="+un+"))"
Attrs = ["displayName"]

l = ldap.initialize(Server)
l.protocol_version = 3
print l.simple_bind_s(DN, Secret)

r = l.search(Base, Scope, Filter, Attrs)
Type,user = l.result(r,60)
Name,Attrs = user[0]
if hasattr(Attrs, 'has_key') and Attrs.has_key('displayName'):
  displayName = Attrs['displayName'][0]
  print displayName

sys.exit()

Running this with myusername@mydomain.co.uk password username gives me one of two errors:

Invalid Credentials - When I mistype or intentionally use wrong credentials it fails to authenticate.

ldap.INVALID_CREDENTIALS: {'info': '80090308: LdapErr: DSID-0C090334, comment: AcceptSecurityContext error, data 52e, vece', 'desc': 'Invalid credentials'}

Or

ldap.OPERATIONS_ERROR: {'info': '00000000: LdapErr: DSID-0C090627, comment: In order to perform this operation a successful bind must be completed on the connection., data 0, vece', 'desc': 'Operations error'}

What am I missing out to bind properly?

I am getting the same errors on fedora and windows.


Source: (StackOverflow)

What does LDAP solve?

I've been in touch with LDAP in many projects I've been involved in but, the truth be told, I don't really understand it. I thought it was just a person directory but after I discovered that it can contain any objects in a hierarchical structure.

I installed openldap in my box and I found many tutorials regarding just the installation.

What is LDAP? What are the scenarios where LDAP is the right choice? What are the LDAP concepts I should know for working with it? What are the advantages of LDAP? Is it used just because old applications used it? Is there a good doc anywhere on internet explaining all this questions?

UPDATE: Complementing the answers I found this link which contains a quick start guide for LDAP newbie like me.


Source: (StackOverflow)

Authenticating against Active Directory with Java on Linux

I have a simple task of authenticating against Active Directory using Java. Just verifying credentials and nothing else. Let's say my domain is "fun.xyz.tld", OU path is unknown, and username/password is testu/testp.

I know there's a few Java libraries out there that simplify this task, but I wasn't successful at implementing them. Most examples that I've found addressed LDAP in general, not specifically Active Directory. Issuing LDAP request means sending an OU path in it, which I don't have. Also, the application that issues LDAP request should be already bound to Active Directory in order to access it... Insecure, since the credentials would have to be stored someplace discoverable. I would like a test bind with test credentials, if possible - this would mean that account is valid.

Last, if possible, is there a way to make such authentication mechanism encrypted? I know that AD uses Kerberos, but not sure if Java's LDAP methods do.

Does anyone has an example of working code? Thanks.


Source: (StackOverflow)