I want to know the best practice for authenticating users using OpenLDAP. I could perform a search using the cn.
But then what if I got multiple hits with similar cn (under different ancestors of course) and they all use the same password?
I tried to use uids but then I got some types of accounts that do not use uids (like mail accounts and the admin cn). Also, when I added some users under the admin cn (which has no uid) I could not login with the admin cn.
What is the unique key that identifies a user?
Note: I am using phpldapadmin to manage the active directory, and openldap for the c++ code.
You can configure your OpenLDAP server to perform the uniqueness check on your chosen attribute. CN is not the most favorable attribute to choose for uniqueness I would choose UID attribute and have a policy in place for username generation.
Related
So... this question is maybe not solely a programming question but I hope one of you can shed some light on my issue:
The base need we have in our software is to query the groups a user is associated too with
LDAP. For this task we actually use parts of LDAP Admin to query the user. Actually we want to query for the UserPrincipalName which at least to my knowledge is the most common way right?
So.. our problem is that the AD is setup such that the user has an UPN like foo#HUS
but the user actually is bound to the domain HUS.adomain.com (aka LDAP base: dc=HUS,dc=adomain,dc=com) and searching using an UPN like foo#HUS.adomain.com does not work - only foo#HUS works. So... the question is:
Is this common?
And is there a name/resource for that?
(sorry I'm quite new to that all...)
The goal would be to use as less parameters in the administration tool as possible
aka only the base (and form from the base the UPN username).
Update: I found at least one resource (in German) that states that this is possible but not recommended by Microsoft for Azure AD. (aka having a different mail address than UPN )
When you initiate a LDAP search using a UPN like foo#HUS.adomain.com it wont work because this value is not present in the userPrincipalName value. When you search for a user by building its UPN using all the domain suffix available in the forest, then you would not consider searching the userPrincipalName attribute.
It is very difficult to build every constructed attribute from base for querying because every Active directory environment would be different. As you have mentioned that you would like to build the attribute from base, it may work if this is the only AD infra that you are targeting. Every AD infra would have its own ways in which it will be setup.
However if you would want your tool to work in any AD environment you would have to consider some other parameters.
UPN is a editable attribute . An organization can set it up or can create a user without a UPN value. Below is example of user created programmatically by using old ADSI libraries. You can repro the same by removing any users userprincipalName attribute value and the user logon account name as shown in the pictures below.
UPN is an optional attribute and a user account can be present in AD without it as well. Coming back to your specific environment in this environment only foo#HUS works because "HUS" might be setup as a valid domain suffix within the Active directory. You can check this by opening the domain.msc console on any domain controller or a machine with Remote Server Administration Tools installed. You would find the UPN suffix as shown below . I changed it in my environment as shown below.
The value you will add will now show up in the . If you remove HUS from here for example any existing user who have user#HUS userPrincipalName populated will get removed because this is a optional constructed attribute in AD. And you will have to setup this for all the users in the environment . For example check below after I changed the username to dh # HUS .
The userprincipalName value also got populated with the same.
Hope this helps clarify your query and understand more on how to use the native Active directory tools to understand more while you develop your custom LDAP search functionality/tool.
We have an application where we store users login name in the format domain\username. We authenticate via windows and then get additional info from our database by matching the domain\username we get from the user to our database.
Now they want to move to the cloud. We authenticate users via apps in Azure AD. However, the user identifier we get back is first.last#domain.com.
I have fiddled around with https://graph.microsoft.com/v1.0/users/email and the select command to try and get the 'old' name. Howev,er I have not yet found out how to get it.
The reason they move to the cloud is that they are merging two ADs. So some users will be DomainA and some DomainB, but in the same tenant. So my first thought was to try and convert the mail to the other format. However, the two different ADs have different naming standards. One has DOMAINA\fila (two first letters from the first name and two first letters from the last name) and the other one has DOMAINB\firlas. Also it feels really ugly to try and solve it that way.
Is it possible to fetch the users loginname formatted as domain\username via Microsoft Graph?
Using the beta edition of Graph, you can obtain the user's domain and username from the onPremisesDomainName and onPremisesSamAccountName properties:
/beta/users?$select=userPrincipalName,onPremisesDomainName,onPremisesSamAccountName
The domain is stored as a FQDN so you'll need to do some translation. For example, domainName.ad.contoso.com might translate to domainName\).
This will give you a workaround so you can match up users with your internal databases. It is however only a temporary solution. Long-term, you really want to migrate to using the userPrincipalName. This is the primary user identifier and guaranteed to be unique within a given tenant.
Azure AD is a little different than the legacy Active Directory. Certain concepts from legacy AD such as Organizational Units (OUs), Group Policy Objects (GPOs), Kerberos Authentication, Lightweight Directory Access Protocol (LDAP), Domain trusts between multiple domains, and several others simply do not exist in the cloud.
I have some understanding problems of LDAP.
When i use an Active Directory Server i can bind with username#domain and a password.
When i use ApacheDS i must give it the full DN of the user and a password.
So i have the folowing Questions:
How do i find out the full dn of a User on a ApacheDS Server with
anonymous privilegs and only the knowledge of username, domain (and
password)?
Is this evenposible? Is the ApacheDS Server even made to be an
alternative to Active Directory?
Generally, LDAP authentication is done in two steps:
Map a given unique user identifier (uid) to its distinguished name using a search operation with a filter like (&(objectClass=user)(uid=%s))
Use a bind operation with that dn to authenticate against your LDAP server.
Active Directory comes with a convenience feature: You can bind using a couple of supported identifiers and AD will do the mapping internally for you.
ApacheDS isn't a plug-and-play substitute for AD, but it's extensible. A Java developer can easily write an authentication interceptor providing the same internal mapping as AD.
As marabu said you can simulate the authentication using a search on the directory before doing the bind.
You can also look for SASL authentication which provides other ways to authenticate.
Here are a list of ApacheDS supported SASL mechanism : http://directory.apache.org/apacheds/advanced-ug/4.1.2-sasl-authn.html
Searching for the user michael#mycontoso.com with the objectSid S-1-5-21-1234567890-123465789-123456789-123456, I only find a Foreign Security Principal CN=S-1-5-21-1234567890-123465789-123456789-123456,CN=ForeignSecurityPrincipals,DC=contoso,DC=com.
That foreign security principal does not contain the properties I have to read, so I guess I have to access the "Home AD" of that FSP.
Does a FSP have a property that always contains the LDAP path of the user object?
Is there a standardized/recommended way how to access the Home AD?
Sadly FSP don't contain the LDAP path of the referenced object.
(if it contain one, then it needs to be replicated once the object is rename/moved)
There seems no easy way to get back the containing AD using the SID from foreign forest.
If in local forest you may do it by binding to LDAP://<SID=S-1-xxxxx>.
A not-so-easy way is to build a domain SID to domain map.
Walk through each domain in trusted forests and build the map using the script here (the "The Script Solution" section).
https://learn.microsoft.com/en-us/archive/blogs/ashleymcglone/powershell-sid-walker-texas-ranger-part-3-exporting-domain-sids-and-trusts
SID of security principals are in the form of <domain SID>-<RID>.
e.g. domain SID of S-1-5-21-1234567890-123465789-123456789-123456 is S-1-5-21-1234567890-123465789-123456789.
By extracting the domain SID (if in .NET you can do it by using SecurityIdentifier class and the AccountDomainSid property) and the map then you can find out the containing domain.
You may try to retrieve the msDS-PrincipalName:
ldapsearch <options> -b "CN=ForeignSecurityPrincipals,DC=contoso,DC=com" "CN=S-1-5-21-1234567890-123465789-123456789-123456" msDS-PrincipalName
FOO\michael#mycontoso.com
Otherwise, the approach is as https://stackoverflow.com/a/27038494/10408280 describes:
Retrieve Domain identifier from first part of SID
Perform a lookup against that domain for the SID of the user or by sAMAccountName
[Rewriting my question based on comments]
My DN in Active Directory is "CN=Jesse Barnum,cn=users,dc=360works,dc=com".
I'm writing a web application which attempts to bind to the LDAP server, using the username and password of the active user. When doing the bind, I use the format "CN=$loginName$,cn=users,dc=360works,dc=com". Therefore, my users need to type in their full name (ie. 'Jesse Barnum'), rather than their shorter UID ('jbarnum').
Since users logging in typically expect to type a short name (like 'jbarnum', rather than 'Jesse Barnum'), I'd like for my DN to use my short name, like this: "CN=jbarnum,cn=users,dc=360works,dc=com". Doesn't it seem like that should be the default behavior (Windows Server 2012)?
So my question is: Can I change how the DN is constructed in Active Directory to use the short name instead of the full name?
You can change that behaviour but why should you? As you want to create a login there are much more elegant and more flexible solutions available.
When creating an LDAP based login I'm always doing the following:
bind to the server with a special account that can search the LDAP. Often that can also be done with a so called "anonymous bind".
search the LDAP for the given username in any attribute you like. A filter of (|(uid=username)(mail=username)(cn=username)) would allow your user to either use the uid, mail or cn to log in.
get the dn from the retrieved result and use that DN whic should be the DN of the users record) for a second bind - this time with the provided Password
That way the DN is completely irrellevant for your login as i is retrieved using the provided information based on attributes.
For an example in PHP have a look at https://gist.github.com/heiglandreas/5689592
The CN can be based on anything, really. It comes down to how you provision your users in the directory. If you use the out-of-box AD Users and Computers or AD Administrative Center tools to create users, they default to the full name format. You can change the CN after the fact, or if you are using something programmatic to create users, then you can create them however you like initially.