Converting Octet String from Active Directory

Posted on 2006-10-30
Medium Priority
Last Modified: 2009-09-18
I am working with AD in C#.

I wrote a simple little app that allows people to search users in AD.

I have the objectSid (SID) coming back as a poperty, and I need to store that data in a database. Later in the app, I will want to search AD using that SID stored.

My problem is converting objectSid ( guessing it's an octec string) to a string value to store it and then converting it back when I need to search with it.

Anyone been down the road with AD and C#

Question by:scaldwe
LVL 10

Accepted Solution

jnhorst earned 1500 total points
ID: 17838984
I am thinking your user object should be castable to an instance of the IADsUser interface, which has a get_GUID method.  You might want to look at storing that and using it later to search with it.


Author Comment

ID: 17842854
Thank You for the reply,  this is what I was looking for ...

using the namespace "System.Security.Principal"

    private String ConvertSID(Byte[] sidBinary)
        SecurityIdentifier SID = new SecurityIdentifier(sidBinary, 0);
        return SID.ToString();

returns me a nice little Unique String I can search on ....

Here is the actual code block this applies to ... maybe this can help someone get their a little faster if they are tasked with this as well.

//Define Search String .. ex: "(&(objectClass=user)(sn=sp*)(objectCategory=person))"
        StringBuilder objS = new StrinBuilder(500);

        DirectorySearcher objSearcher = new DirectorySearcher("LDAP://yourdomain/");
        objSearcher.Filter = objS.ToString();
        objSearcher.PropertiesToLoad.Add("objectSid"); //returns as an octet string so you must convert it.

        SearchResult objResults;
        SearchResultCollection objResultCollection = objSearcher.FindAll();

        //Now to grab the values I set to Load with the PopertiestoLoad method ...
        String firstName = (String)objResults.Properties["givenName"][0];
        String lastName = (String)objResults.Properties["sn"][0];
        String SID = ConvertSID((Byte[])objResults.Properties["objectSid"][0];

Hope this helps someone ....


Expert Comment

ID: 25369395
For anyone interested, I had to do the reverse of this: finding all users that belong to a group, even if they are listed as primary group member. (I excluded 513 which is the default "Domain Users" group).
if (sr.Properties["name"] == null) continue;
if (sr.Properties["name"].Count == 0) continue;
string name = (string)sr.Properties["name"][0];
string gSID = ConvertSID((Byte[])sr.Properties["objectSid"][0]);
string rSID = gSID.Substring(gSID.LastIndexOf('-') + 1);
int irSID = 0;
int.TryParse(rSID, out irSID);
ResultPropertyValueCollection member = sr.Properties["member"];
List<string> members = new List<string>();
foreach (string i in member)
if (irSID == 0 || rSID != "513")
  DirectorySearcher dsearch2 = new DirectorySearcher();
  SearchResultCollection sResult2;
  dsearch2.PageSize = 500;
  dsearch2.SizeLimit = 500;
  dsearch2.ReferralChasing = ReferralChasingOption.All;
  dsearch2.SearchScope = SearchScope.Subtree;
  dsearch2.Filter = "(&(primaryGroupID=" + rSID + "))";
  dsearch2.SearchRoot = new DirectoryEntry("LDAP://DC=contoso,DC=com");
  sResult2 = dsearch2.FindAll();
  foreach (SearchResult sr2 in sResult2)

Open in new window


Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

I recently went through the process of creating a Calendar Control of events with the basis of using a database to keep track of the dates that are selectable, one requirement was to have the selected date pop-up in a simple lightbox.  At first this…
An ASP.NET Web Form User Control is not newly introduced in ASP.NET. In fact, it was an old technology yet still playing a role to generate web content, especially when we want to use it to have a better and easy way to control part of the web conte…
Watch the video of Kernel Migrator for SharePoint, which demonstrate the process easily of migration from SharePoint to SharePoint, OneDrive for Business & Google Drive servers, Public Folder to SharePoint, File Server to SharePoint. The tool has va…
Did you know PowerShell can save you time with SaaS platforms? Simply leverage RESTfulAPIs to build your own PowerShell modules. These will kill repetitive tickets and tabs, using the command Invoke-RestMethod. Tune into this webinar to learn how…
Suggested Courses

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question