CODEWITHSUNDEEP
c#.netwindowssecurity
Clinton Pierce
Clinton Pierce

Reputation: 13209

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

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 in the process' lifetime it's going to attempt some things that require admin privileges.

I'd like to be able to test up front if the process has those rights rather than later on.

Upvotes: 51

Views: 51281

Answers (10)

Eric J.
Eric J.

Reputation: 150218

The following is tested to work in .NET Core 3 on Windows 10 and Ubuntu Linux:

[DllImport("libc")]
public static extern uint getuid(); // Only used on Linux but causes no issues on Windows

static bool RunningAsAdmin()
{
    if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
    {
        using var identity = WindowsIdentity.GetCurrent();
        WindowsPrincipal principal = new WindowsPrincipal(identity);
        return principal.IsInRole(WindowsBuiltInRole.Administrator);
    }
    else return getuid() == 0;
}

It returns true when UAC is in effect (Windows) or when the application is running as superuser on Linux (e.g. sudo myapp).

If anyone has the opportunity to test on MacOS, please share your findings.

Upvotes: 3

OzBob
OzBob

Reputation: 4530

There are 4 possible Methods - I prefer:

(new WindowsPrincipal(WindowsIdentity.GetCurrent())).IsInRole(WindowsBuiltInRole.Administrator);

Here is code to give you a list of all the relevant claim data for your current user's Identity.

NOTE: there is a big difference beween the claims list that is returned between WindowsPrincipal.Current.Claims and (new WindowsPrincipal(WindowsIdentity.GetCurrent())).Claims 

Console.WriteLine("press the ENTER key to start listing user claims:");
Console.ReadLine();

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
bool canBeAdmin = (new WindowsPrincipal(WindowsIdentity.GetCurrent())).IsInRole(WindowsBuiltInRole.Administrator);
Console.WriteLine("GetCurrent IsInRole: canBeAdmin:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = (new WindowsPrincipal(WindowsIdentity.GetCurrent())).Claims.Any((c) => c.Value == "S-1-5-32-544");
Console.WriteLine("GetCurrent Claim: canBeAdmin?:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = (new WindowsPrincipal(WindowsIdentity.GetCurrent())).IsInRole("Administrator");
Console.WriteLine("GetCurrent IsInRole \"Administrator\": canBeAdmin?:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = (new WindowsPrincipal(WindowsIdentity.GetCurrent())).IsInRole("Admin");
Console.WriteLine("GetCurrent IsInRole \"Admin\": canBeAdmin?:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = WindowsPrincipal.Current.IsInRole("Admin");
Console.WriteLine("Current IsInRole \"Admin\": canBeAdmin:{0}", canBeAdmin);


Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = WindowsPrincipal.Current.IsInRole("Administrator");
Console.WriteLine("Current IsInRole \"Administrator\": canBeAdmin:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
canBeAdmin = WindowsPrincipal.Current.Claims.Any((c) => c.Value == "S-1-5-32-544");
Console.WriteLine("Current Claim: canBeAdmin?:{0}", canBeAdmin);

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
Console.WriteLine("WindowsPrincipal Claims:");
Console.WriteLine("---------------------");

var propertyCount = 0;
foreach (var claim in WindowsPrincipal.Current.Claims)
{
    Console.WriteLine("{0}", propertyCount++);
    Console.WriteLine("{0}", claim.ToString());
    Console.WriteLine("Issuer:{0}", claim.Issuer);
    Console.WriteLine("Subject:{0}", claim.Subject);
    Console.WriteLine("Type:{0}", claim.Type);
    Console.WriteLine("Value:{0}", claim.Value);
    Console.WriteLine("ValueType:{0}", claim.ValueType);
}

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
Console.WriteLine("WindowsPrincipal Identities Claims");
Console.WriteLine("---------------------");

propertyCount = 0;
foreach (var identity in WindowsPrincipal.Current.Identities)
{
    int subPropertyCount = 0;
    foreach (var claim in identity.Claims)
    {
        Console.WriteLine("{0} {1}", propertyCount, subPropertyCount++);
        Console.WriteLine("{0}", claim.ToString());
        Console.WriteLine("Issuer:{0}", claim.Issuer);
        Console.WriteLine("Subject:{0}", claim.Subject);
        Console.WriteLine("Type:{0}", claim.Type);
        Console.WriteLine("Value:{0}", claim.Value);
        Console.WriteLine("ValueType:{0}", claim.ValueType);
    }
    Console.WriteLine();
    propertyCount++;
}

Console.WriteLine("---------------------");
Console.WriteLine("---------------------");
Console.WriteLine("Principal Id Claims");
Console.WriteLine("---------------------");

var p = new WindowsPrincipal(WindowsIdentity.GetCurrent());
foreach (var claim in (new WindowsPrincipal(WindowsIdentity.GetCurrent())).Claims)
{
    Console.WriteLine("{0}", propertyCount++);
    Console.WriteLine("{0}", claim.ToString());
    Console.WriteLine("Issuer:{0}", claim.Issuer);
    Console.WriteLine("Subject:{0}", claim.Subject);
    Console.WriteLine("Type:{0}", claim.Type);
    Console.WriteLine("Value:{0}", claim.Value);
    Console.WriteLine("ValueType:{0}", claim.ValueType);
}

Console.WriteLine("press the ENTER key to end");
Console.ReadLine();

Upvotes: 0

Noah Stahl
Noah Stahl

Reputation: 7623

Other answers leveraging the IsInRole method only return true if the user is running with an elevated token, as others have commented. Here is a potential alternative for checking just for local Administrators group membership in both a standard and elevated context:

bool isAdmin = false;
using (var user = WindowsIdentity.GetCurrent())
{
    var principal = new WindowsPrincipal(user);
    // Check for token claim with well-known Administrators group SID
    const string LOCAL_ADMININSTRATORS_GROUP_SID = "S-1-5-32-544";
    if (principal.Claims.SingleOrDefault(x => x.Value == LOCAL_ADMININSTRATORS_GROUP_SID) != null)
    {
        isAdmin = true;
    }
}

return isAdmin;

Upvotes: 2

Wadih M.
Wadih M.

Reputation: 13462

This will check if user is in the local Administrators group (assuming you're not checking for domain admin permissions)

using System.Security.Principal;

public bool IsUserAdministrator()
{
    //bool value to hold our return value
    bool isAdmin;
    WindowsIdentity user = null;
    try
    {
        //get the currently logged in user
        user = WindowsIdentity.GetCurrent();
        WindowsPrincipal principal = new WindowsPrincipal(user);
        isAdmin = principal.IsInRole(WindowsBuiltInRole.Administrator);
    }
    catch (UnauthorizedAccessException ex)
    {
        isAdmin = false;
    }
    catch (Exception ex)
    {
        isAdmin = false;
    }
    finally
    {
        if (user != null)
            user.Dispose();
    }
    return isAdmin;
}

Upvotes: 79

David Moore
David Moore

Reputation: 2526

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);

/// <summary>
/// Passed to <see cref="GetTokenInformation"/> to specify what
/// information about the token to return.
/// </summary>
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
}

/// <summary>
/// The elevation type for a user token.
/// </summary>
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);
}

Upvotes: 31

Jens
Jens

Reputation: 25593

Using the .NET Framework 4.5, it seems to be easier to check if a user is in the administrators group:

WindowsPrincipal principal = WindowsPrincipal.Current;
bool canBeAdmin = principal.Claims.Any((c) => c.Value == "S-1-5-32-544");

Upvotes: 3

Alex G.
Alex G.

Reputation: 57

Tried Erwin's code but it didn't compile.

Got it to work like this:

[DllImport("shell32.dll")] public static extern bool IsUserAnAdmin();

Upvotes: 4

Erwin Mayer
Erwin Mayer

Reputation: 18670

What about:

using System.Runtime.InteropServices;

internal static class Useful {
    [DllImport("shell32.dll", EntryPoint = "IsUserAnAdmin")]
    public static extern bool IsUserAnAdministrator();
}

Upvotes: 0

Jacob Proffitt
Jacob Proffitt

Reputation: 12778

If you want to make sure your solution works in Vista UAC, and have .Net Framework 3.5 or better, you might want to use the System.DirectoryServices.AccountManagement namespace. Your code would look something like:

bool isAllowed = false;
using (PrincipalContext pc = new PrincipalContext(ContextType.Machine, null))
{
    UserPrincipal up = UserPrincipal.Current;
    GroupPrincipal gp = GroupPrincipal.FindByIdentity(pc, "Administrators");
    if (up.IsMemberOf(gp))
        isAllowed = true;
}

Upvotes: 17

Bob The Janitor
Bob The Janitor

Reputation: 20802

Use can use WMI with something like this to find out if the account is an admin, and just about anything else you want to know about there account

using System;
using System.Management;
using System.Windows.Forms;

namespace WMISample
{
    public class MyWMIQuery
    {
        public static void Main()
        {
            try
            {
                ManagementObjectSearcher searcher = 
                    new ManagementObjectSearcher("root\\CIMV2", 
                    "SELECT * FROM Win32_UserAccount"); 

                foreach (ManagementObject queryObj in searcher.Get())
                {
                    Console.WriteLine("-----------------------------------");
                    Console.WriteLine("Win32_UserAccount instance");
                    Console.WriteLine("-----------------------------------");
                    Console.WriteLine("AccountType: {0}", queryObj["AccountType"]);
                    Console.WriteLine("FullName: {0}", queryObj["FullName"]);
                    Console.WriteLine("Name: {0}", queryObj["Name"]);
                }
            }
            catch (ManagementException e)
            {
                MessageBox.Show("An error occurred while querying for WMI data: " + e.Message);
            }
        }
    }
}

To make it easier to get started download WMI Creator

you can also use this it access active directory (LDAP) or anything else on you computer/network

Upvotes: 1

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