Active Directory Searcher - Part 2

We finished up Part 1 with this script :

$LDAPdomain = [ADSI]('LDAP://dc=other,dc=com')

$Searcher = New-Object System.DirectoryServices.DirectorySearcher($LDAPdomain,"(objectclass=user)","name","subtree")
$Results = $Searcher.FindAll()
foreach ($Object in $Results){
  $Object.Properties.name
}

I am going to take things a little further by adding variables which in turn will help remove any hardcoded elements of the script.

A quick one first, after running your search for all users, did you notice that you got exactly 1000 results (assuming that you have at least 1000 users in your domain)?  This is the maximum number of records that you can return in one go using LDAP.  What you need to do is tell the searcher to page results by adding this command :

$Searcher.pagesize = 1000

This will return the first 1000, but go off and find the next 1000 straight after, and so on.


The next thing is to use variables instead of hard coding in the new-object line.  Apart from making edits to your code easier (especially if you are handing the script over to someone less familiar with powershell), this has other benefits as you will see later :

$ObjectCategory = "user"
$ObjectProplist = "name","samaccountname","whencreated"
$LdapQuery = "(&(objectCategory=$ObjectCategory)(name=ad*))"
$LDAPdomain = [ADSI]('LDAP://dc=other,dc=com'$Searcher = New-Object System.DirectoryServices.DirectorySearcher($LDAPdomain, $LdapQuery, $ObjectProplist, "subtree")

$Searcher.pagesize = 1000
$Results = $Searcher.FindAll()
etc...

Not too trickey eh?  As we now have all variables for the searcher object, lets look at getting rid of the hard coded domain name.  This becomes very handy if you have multiple forests to manage and search as the same code will work across them all.  We have to go back to .net to do this.


We have 2 classes we can use, System.DirectoryServices.ActiveDirectory.forest or System.DirectoryServices.ActiveDirectory.domain. If you use forest, you can then search each domain in the forest, or you can target just a single domain with domain.  The constructor I find i use most is 

$domains = [System.DirectoryServices.ActiveDirectory.forest]::getcurrentforest().get_domains()

I use the forest class and call the getcurrentforest() method, which (funnily enough) gets the current forest.  Now, the beauty of  powershell is that you don't have to store that in a variable if you don't need to, you can just call the method straight from the forest object get_domains() and store them.  This is essentially a quick way of doing this :

$forest = [System.DirectoryServices.ActiveDirectory.forest]::getcurrentforest()

$domains = $forest.get_domains()

So what we are left with is an array of how ever many domains are in your forest ready for you to do a foreach-object against.  Remember in part 1 I said that there were many way of getting a directory entry object, well here is another one. When we loop round our array of domain objects, we can call the method $domain.getdirectoryentry() to pass to our searcher.  This removes the hard coded domain and makes things a lot simpler. 

$domains = [System.DirectoryServices.ActiveDirectory.forest]::getcurrentforest().get_domains()

$ObjectCategory = "user"

$ObjectProplist = "name","samaccountname","whencreated"

$LdapQuery = "(&(objectCategory=$ObjectCategory)(name=ad*))"

foreach ($domain in $domains){

      ($domain).name

      $LDAPdomain = $domain.GetDirectoryEntry()

      $Searcher = New-Object System.DirectoryServices.DirectorySearcher($LDAPdomain, $LdapQuery, $ObjectProplist,"subtree")

      $Searcher.pagesize = 1000

      $Results = $Searcher.FindAll()

      foreach ($Object in $Results){

           $Object.Properties.name

      }

}

Cool!  No more hard coding.  ahhhhh but there is.  We are only outputting the name property, what about the other properties in the list?  Here's where using a variable starts to be handy.  You can do a foreach loop for every object in the array any output everything you have searched for, and all by only changing the $objectproplist array : 

$domains = [System.DirectoryServices.ActiveDirectory.forest]::getcurrentforest().get_domains()

$ObjectCategory = "user"

$ObjectProplist = "name","samaccountname","whencreated"

$LdapQuery = "(&(objectCategory=$ObjectCategory)(name=ad*))"

foreach ($domain in $domains){

      ($domain).name

      $LDAPdomain = $domain.GetDirectoryEntry()

      $Searcher = New-Object System.DirectoryServices.DirectorySearcher($LDAPdomain, $LdapQuery, $ObjectProplist,"subtree")

      $Searcher.pagesize = 1000

      $Results = $Searcher.FindAll()

      foreach ($Object in $Results){

            foreach ($prop in $ObjectProplist){

                  $Object.Properties.$prop

                 }

      }

}

I will be finishing up with Part 3 looking at a few techniques in how to better deal with the information gathered including using switch statements, traps and outputting the information to an array proir to exporting to CSV.