The best way to resolve display username by SID?

Question

I read a list of SIDs from the registry, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList.

How would one resolve the display username (e.g. DOMAIN\user, BUILT-IN\user) given the SID string in C#?

Recidivism

Answer 1

The Win32 API function LookupAccountSid() is used to find the name that corresponds to a SID.

LookupAccountSid() has the following signature:

BOOL LookupAccountSid(LPCTSTR lpSystemName, PSID Sid,LPTSTR Name, LPDWORD cbName,
                       LPTSTR ReferencedDomainName, LPDWORD cbReferencedDomainName,
                       PSID_NAME_USE peUse);

MSDN Ref.

Here's the P/Invoke reference (with sample code): http://www.pinvoke.net/default.aspx/advapi32.LookupAccountSid

[DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError = true)]
static extern bool LookupAccountSid (
  string lpSystemName,
  [MarshalAs(UnmanagedType.LPArray)] byte[] Sid,
  StringBuilder lpName,
  ref uint cchName,
  StringBuilder ReferencedDomainName,
  ref uint cchReferencedDomainName,
  out SID_NAME_USE peUse); 

Watteau

Is there any other way to do it without using p/invoke in C#? – Recidivism

@DennisC you can do it without P/Invoke. Please see my answer: #7593505 – Candelaria

@EriawanKusumawardhono I guess you may not read the questions very well. Because they are exactly opposite API – Recidivism

Answer 2

Just found it on the pinvoke.net.

Alternative Managed API: Available in .Net 2.0:

using System.Security.Principal;

// convert the user sid to a domain\name
string account = new SecurityIdentifier(stringSid).Translate(typeof(NTAccount)).ToString();

Recidivism

This solution is not reliable in all situations. There are sometimes SIDs which cannot be translated and this will throw an exception. I've found LookupAccountSid() to be more reliable. – Poser