How do I convert an Active Directory objectGuid to a readable string?

Question

I'm using Novell.Directory.Ldap in a Xamarin mobile application, written in C#.

Using Novell, I am able to authenticate a user based on domain, username, and password using

LdapConnection.bind(username, password);

Then, I perform a search, using the sAMAccountName, which is equivalent to the supplied username.

After all this, which works successfully, I need to get the user's objectGuid so that I can query external databases, which use that guid as a key. The problem is, when I get the guid back form the LdapSearchResults, it's encoded somehow. And I cannot figure out how to get the readable string representation of this guid.

Does anyone have more information on this? I would imagine that the guid is encoded somehow, but how it's encoded, I do not know. I have tried

System.Convert.FromBase64String 

and that didn't help. I appreciate the help guys, let me know if I can post anymore information that'd be helpful.

private void Login()
{
    if (LOG.isInfoEnabled())
    {
        LOG.info("Attempting LDAP logon . . .");

        if (LOG.isDebugEnabled())
        {
            LOG.debug("Host: " + this.ldapHost);
            LOG.debug("Port: " + this.ldapPort);
            LOG.debug("SearchBase: " + this.ldapSearchBase);
        }
    }

    LdapConnection conn = new LdapConnection();

    try
    {
        conn.Connect(this.ldapHost, this.ldapPort);

        if (LOG.isDebugEnabled())
        {
            LOG.debug("connected?: " + conn.Connected.ToString());
        }
    }
    catch (Exception e)
    {
        LOG.error("An exception occurred while attempting to connect to AD server!", e);

        // INFORM USER ABOUT ERROR
        authError(Resource.String.error_unknown);
    }

    if (!string.IsNullOrEmpty(this.editTextUserName.Text) && !string.IsNullOrEmpty(this.editTextPassword.Text))
    {
        // HIDE KEYBOARD
        var imm = (InputMethodManager)GetSystemService(Context.InputMethodService);
        imm.HideSoftInputFromWindow(editTextPassword.WindowToken, HideSoftInputFlags.NotAlways);

        // HIDE 'LOGON' BUTTON WHILE LOGGING ON
        this.buttonLogin.Visibility = ViewStates.Invisible;

        try
        {
            // PERFORM AUTHENTICATION
            conn.Bind(this.userName, this.userPassword);

            if (LOG.isDebugEnabled())
            {
                LOG.debug("conn.Bound?: " + conn.Bound);
            }

            if (conn.Bound)
            {
                if (LOG.isDebugEnabled())
                {
                    LOG.debug("authentication successful");
                }

                string[] name = this.userName.Split('\\');
                LOG.debug("name[0]: " + name[0]);
                LOG.debug("name[1]: " + name[1]);

                string filter = "(sAMAccountName=" + name[1] + ")";
                string guid = "";

                LdapSearchResults searchResults = conn.Search(
                    this.ldapSearchBase, // search base
                    LdapConnection.SCOPE_SUB, // search scope  
                    filter, // filter
                    null, // attributes
                    false); // attributes only

                while (searchResults.hasMore())
                {
                    LdapEntry nextEntry = null;

                    try
                    {
                        nextEntry = searchResults.next();
                        guid = nextEntry.getAttribute("objectGUID").StringValue;
                    }
                    catch (LdapException e)
                    {
                        LOG.error("An exception occurred while attempting to get next search result!", e);
                        continue;
                    }
                }

                Intent intent = new Intent(this, typeof(DashboardActivity));
                intent.PutExtra("guid", guid);

                StartActivity(intent);
            }
            else
            {
                // INFORM USER ABOUT ERROR
                authError(Resource.String.error_auth);
            }
        }
        catch (LdapException ldape)
        {
            LOG.error("An exception occurred while attempting to authenticate user credentials!", ldape);

            // INFORM USER ABOUT ERROR
            authError(Resource.String.error_auth);
        }
        finally
        {
            conn.Disconnect();
        }
    }
    else
    {
        conn.Disconnect();
    }
}

Answer 1

I'm not sure if the Novell library encodes it in some other way, but System.DirectoryServices provides the GUID as a byte array. You can get this to a readable string using the System.Guid struct:

new Guid((System.Byte[])this.GUID).ToString()