See if user is part of Active Directory group in C# + Asp.net

Question

I need a way to see if a user is part of an active directory group from my .Net 3.5 asp.net c# application.

I am using the standard ldap authentication example off o

Answer 1

You could try the following code:

public bool Check_If_Member_Of_AD_Group(string username, string grouptoCheck, string domain, string ADlogin, string ADpassword)
{
    
     try {
        
        string EntryString = null;
        EntryString = "LDAP://" + domain;
        
        DirectoryEntry myDE = default(DirectoryEntry);
        
        grouptoCheck = grouptoCheck.ToLower();
        
        
        myDE = new DirectoryEntry(EntryString, ADlogin, ADpassword);
        
        DirectorySearcher myDirectorySearcher = new DirectorySearcher(myDE);
        
        myDirectorySearcher.Filter = "sAMAccountName=" + username;
        
        myDirectorySearcher.PropertiesToLoad.Add("MemberOf");
        
        SearchResult myresult = myDirectorySearcher.FindOne();
        
        int NumberOfGroups = 0;
        
        NumberOfGroups = myresult.Properties["memberOf"].Count - 1;
        
        string tempString = null;
        
        while ((NumberOfGroups >= 0)) {
            
            tempString = myresult.Properties["MemberOf"].Item[NumberOfGroups];
            tempString = tempString.Substring(0, tempString.IndexOf(",", 0));
            
            tempString = tempString.Replace("CN=", "");
            
            tempString = tempString.ToLower();
            tempString = tempString.Trim();
            
            if ((grouptoCheck == tempString)) {
                
                    
                return true;
            }
            
                
            NumberOfGroups = NumberOfGroups - 1;
        }
        
            
        return false;
    }
    catch (Exception ex) {
        
        System.Diagnostics.Debugger.Break();
    }
    //HttpContext.Current.Response.Write("Error: 

" & ex.ToString)
}