Can WindowsIdentity.GetCurrent() return null?

Question

ReSharper warns me about a possible NullReferenceException in

WindowsIdentity windowsIdentity = new WindowsIde         


        

Answer 1

Using ILSpy, you can look at a decompiled version of GetCurrent and GetCurrentInternal, which GetCurrent calls.

GetCurrent:

public static WindowsIdentity GetCurrent()
{
    return WindowsIdentity.GetCurrentInternal(TokenAccessLevels.MaximumAllowed, false);
}

GetCurrentInternal:

internal static WindowsIdentity GetCurrentInternal(TokenAccessLevels desiredAccess, bool threadOnly)
{
    int errorCode = 0;
    bool flag;
    SafeTokenHandle currentToken = WindowsIdentity.GetCurrentToken(desiredAccess, threadOnly, out flag, out errorCode);
    if (currentToken != null && !currentToken.IsInvalid)
    {
        WindowsIdentity windowsIdentity = new WindowsIdentity();
        windowsIdentity.m_safeTokenHandle.Dispose();
        windowsIdentity.m_safeTokenHandle = currentToken;
        return windowsIdentity;
    }
    if (threadOnly && !flag)
    {
        return null;
    }
    throw new SecurityException(Win32Native.GetMessage(errorCode));
}

Since threadOnly is always false when calling from GetCurrent, and the currentToken must be valid for the other return statement, I don't think you're at risk of getting a null WindowsIdentity.