In .NET/C# test if process has administrative privileges

Question

Is there a canonical way to test to see if the process has administrative privileges on a machine?

I\'m going to be starting a long running process, and much later

Answer 1

Starting with Wadih M's code, I've got some additional P/Invoke code to try and handle the case of when UAC is on.

http://www.davidmoore.info/blog/2011/06/20/how-to-check-if-the-current-user-is-an-administrator-even-if-uac-is-on/

First, we’ll need some code to support the GetTokenInformation API call:

[DllImport("advapi32.dll", SetLastError = true)]
static extern bool GetTokenInformation(IntPtr tokenHandle, TokenInformationClass tokenInformationClass, IntPtr tokenInformation, int tokenInformationLength, out int returnLength);

/// 

/// Passed to  to specify what
/// information about the token to return.
/// 
enum TokenInformationClass
{
     TokenUser = 1,
     TokenGroups,
     TokenPrivileges,
     TokenOwner,
     TokenPrimaryGroup,
     TokenDefaultDacl,
     TokenSource,
     TokenType,
     TokenImpersonationLevel,
     TokenStatistics,
     TokenRestrictedSids,
     TokenSessionId,
     TokenGroupsAndPrivileges,
     TokenSessionReference,
     TokenSandBoxInert,
     TokenAuditPolicy,
     TokenOrigin,
     TokenElevationType,
     TokenLinkedToken,
     TokenElevation,
     TokenHasRestrictions,
     TokenAccessInformation,
     TokenVirtualizationAllowed,
     TokenVirtualizationEnabled,
     TokenIntegrityLevel,
     TokenUiAccess,
     TokenMandatoryPolicy,
     TokenLogonSid,
     MaxTokenInfoClass
}

/// 

/// The elevation type for a user token.
/// 
enum TokenElevationType
{
    TokenElevationTypeDefault = 1,
    TokenElevationTypeFull,
    TokenElevationTypeLimited
}

Then, the actual code to detect if the user is an Administrator (returning true if they are, otherwise false).

var identity = WindowsIdentity.GetCurrent();
if (identity == null) throw new InvalidOperationException("Couldn't get the current user identity");
var principal = new WindowsPrincipal(identity);

// Check if this user has the Administrator role. If they do, return immediately.
// If UAC is on, and the process is not elevated, then this will actually return false.
if (principal.IsInRole(WindowsBuiltInRole.Administrator)) return true;

// If we're not running in Vista onwards, we don't have to worry about checking for UAC.
if (Environment.OSVersion.Platform != PlatformID.Win32NT || Environment.OSVersion.Version.Major < 6)
{
     // Operating system does not support UAC; skipping elevation check.
     return false;
}

int tokenInfLength = Marshal.SizeOf(typeof(int));
IntPtr tokenInformation = Marshal.AllocHGlobal(tokenInfLength);

try
{
    var token = identity.Token;
    var result = GetTokenInformation(token, TokenInformationClass.TokenElevationType, tokenInformation, tokenInfLength, out tokenInfLength);

    if (!result)
    {
        var exception = Marshal.GetExceptionForHR( Marshal.GetHRForLastWin32Error() );
        throw new InvalidOperationException("Couldn't get token information", exception);
    }

    var elevationType = (TokenElevationType)Marshal.ReadInt32(tokenInformation);

    switch (elevationType)
    {
        case TokenElevationType.TokenElevationTypeDefault:
            // TokenElevationTypeDefault - User is not using a split token, so they cannot elevate.
            return false;
        case TokenElevationType.TokenElevationTypeFull:
            // TokenElevationTypeFull - User has a split token, and the process is running elevated. Assuming they're an administrator.
            return true;
        case TokenElevationType.TokenElevationTypeLimited:
            // TokenElevationTypeLimited - User has a split token, but the process is not running elevated. Assuming they're an administrator.
            return true;
        default:
            // Unknown token elevation type.
            return false;
     }
}
finally
{    
    if (tokenInformation != IntPtr.Zero) Marshal.FreeHGlobal(tokenInformation);
}