Let's talk about Booleans.
A Boolean is an easy-to-use configuration switch.
It enables or disables specific parts of the SELinux policy.
And for an overview of all Booleans,
you can use SEManagedBoolean minus L,
or alternatively, GetSable minus A, exactly the same output.
You'll see that it's a limited list of Booleans.
And it's all about specific functionality.
And if you see something of which you think,
hey, I need that, use SetSable minus uppercase P,
followed by the name of the Boolean, and on or off.
And also convenient, if you want to see
if anything has changed in relation
to the default configuration, SEManagedBoolean minus L
minus uppercase C. Let me show you.
So I'm using GetSable minus A. And how many are there?
WC minus L is showing only 326.
That's not so much.
Now, let's try to understand what they are doing.
I'm grabbing on HTTP.
And there we can see that the Booleans are
about specific functionality that you may or may not
want to use on your HTTP server.
Maybe that's too much.
Let's do it on FTP to make it a little bit easier.
So here, for instance, we have FTPD anonymous write.
Now, what does that mean?
Well, it means that by default, it is off.
And if I'm going to edit my ETC VS FTPD, VS FTPD.conf,
there is an anonymous enable is no.
Well, I'm going to change that to yes.
And if I want to do anonymous enable,
well, I also need to make sure that I have a directory var
FTP pub.
Oh, that already exists.
That is good.
And I need to check the settings on the directory var FTP pub.
And oops, the directory and not the contents.
Well, we can see public content T. That is looking good.
And what does that mean?
Well, that means that if I copy ETC hosts to var FTP pub,
and I'm opening an FTP client.
Shall I quickly do that?
DNF install minus Y LFTP.
This is a speed introduction to FTP.
That's a blast from the past.
This is not too important.
But I want to show you something where you can understand,
well, the Boolean is about.
And also something that we can analyze
with SE alert, which is in the next lesson.
So I am going to use LFTP to local host.
And there I'm using LS.
And oh, it's sending commands.
Now, is my FTP server running?
System CTL status VS FTPD.
Yeah, it is running.
So what is going on?
Well, what is going on is what we see right here.
Our user is anonymous.
So I'm trying to access this server anonymously.
And what did we see in the Boolean?
Well, in the Boolean, we have seen that FTPD anonymous write,
or that is for anonymous write, that is disabled.
Well, maybe something else is wrong.
But hey, I want to make sure that anonymous users can write
as well.
So I'm using set SE bool minus uppercase P FTPD underscore
anon write on.
And that will persistently switch it on.
Now, does that make that I can use my FTPD server
as an anonymous user?
I'm not sure yet.
But we will figure that out in the next video.