Given a DirectoryEntry, how can I get the Forest object?

Question

Let's say I would like to implement an Extension method that allows me to get the Forest object for every DirectoryEntry object.

My skeleton code:

public static Forest GetForest(DirectoryEntry de) {
    string forestDnsName = //DoSomethingWith(de.Path); ?
    DirectoryContext context = new DirectoryContext(DirectoryContextType.Forest, forestDnsName);
    return Forest.GetForest(context)
}

But I am unsure how I could get the Forest. Does anyone know how to get it?

Answer 1

No sample code, just some general steps:

1. Get the "distinguishedname" attribute.
2. Get the "DC=xxx,DC=yyy" segment from the DN
3. Convert above to domain name (remove all "DC=", then replace "," with ".")
4. Connect to LDAP://[domain name]/RootDSE
5. Read "rootDomainNamingContext"
6. Convert to forest name by repeating step 3
7. You know how to create Forest object from forest name already

If you will call this extension method many times, you may build a domain name to Forest object map to reduce AD traffic (skip step 4 - 7).