Fetching UPN Alias from Domain Name and vice versa with LDAP

Question

Need a quick help.

I am using LDAP for authentication with active directory,

I want to know how to fetch all UPN alias of a domain & domain from UPN alias,

Is their any way to get this.

Please help!

Answer 1

You can actually read these values from AD over LDAP from the Configuration tree. If you read the following object: CN=Partitions,CN=Configuration,DC=your,DC=domain,DC=com that will contain an attribute called uPNSuffixes.

This attribute contains only the extra suffixes not the default one (you will have to get that from the domain name itself I guess).

Rule is, if the uPNSuffixes attribute is not available, only the default UPN suffix is valid.

EDIT: a simple example would be this:

public List<String> getUpnSuffixes( LdapContext ctx, String domainName )
{
   // Domain name should be in DC=you,DC=domain,DC=com format
   String domConfig = "CN=Partitions,CN=Configuration," +domainName ;
   List<String> names = new ArrayList<String>();
   // Dirty hack to get the default suffix
   names.add( domainName.replaceAll( "DC=", "" ).replaceAll( "," , "." );
   // Read the configuration
   Attributes attrs = ctx.getAttributes( domConfig , new String[] { "uPNSuffixes" } );
   Attribute attr = attrs.get( "uPNSuffixes" );
   for ( int i=0; i<attr.size(); i++ )
   {
       names.add( attr.get(i) );
   }
   // Now you have all the suffixes in the "names" list. 
   return names;
}

Note that you will probably have to catch NamingException for the ctx.getAttributes() and attr.get() calls.

EDIT 2: if you want the reverse, search for the uPNSuffixes attribute value:

public String getDomainFromUpnSuffix( LdapContext ctx, String uPNSuffix )
{
   String filter = "(&(CN=Partitions)(uPNSuffixes=" + uPNSuffix + "))" ;
   // Find the configuration for this suffix
   NamingEnumeration<SearchResult> results = ctx.search( "", filter, null );
   while ( results.hasMore() )
   {
       SearchResult result = results.next();
       return result.getNameInNamespace();
   }
   return null;
}