Python 3 Programming Tutorial - Sockets simple port scanner

Key Takeaways

Hello everybody and welcome to the second part of verse socket tutorial series. In this video, what I'm going to be showing you guys is a simple what's known as a port scanner. Um, basically what a port scanner is going to do is exactly what it sounds like. It just scans ports and it tells you whether or not the port is open or closed. Now, generally we kind of have an idea of what the lower ports in their situation is going to be. Uh, but you can quickly find out if someone's using something like FTP or if they're using SSH or whatever. And then obviously port 80 will be open um for like websites and stuff, but you can use this on other people's computers or you can even use it on your own computer to find out your own vulnerabilities. Naturally with this uh even though this isn't a very good port scanner, I'm not uh responsible for how you decide to use a port scanner. I'm just showing you um how they work basically. So with that, um, let's go ahead and we'll keep, um, S equals. We'll keep, uh, we don't want to keep the port. We don't need any of the server IP. We're not even going to make this request. We don't need to send any requests and we don't need a result. And we don't need any of this. So, uh, now what we can do here is we can say, uh, define Pcan for define port scan. And we can say the parameter is port. Then we define what s uh define s.connect and then we're going to connect server and then uh to port and we've defined server up here. Finally um what we'll actually what we'll do here is we'll say try and if that works we'll return a true uh except uh return a false. Oops. a false. And so what this is asking basically is we're going to attempt to connect. If we can connect, then we'll make a connection and it's going to return true for us. If we cannot connect, it means the port is not open and it's going to return a false for us. Okay. Um and in fact, uh well, no, we'll leave this up here. You could put any anything up here. You could also allow for like input or something like that. But anyway, and now what we'll do is we'll say 4x in range and we'll say um zero actually we'll say 1 to 26. Okay, so this will test port number one through port number 25 and um then we're going to say if pcan x uh print uh port x is open. So basically what we're doing is we're passing that x value whichever x is in this list of sound like my power almost dropped. That was weird. Anyway, um for X in this list of 1 through 26, um it's going to throw that value through the port parameter of our PCAN function and it's going to test it. And then if Pcan X, so what we're asking here is if true. Um so if PCAN X PCAN X is either returning true or false. So we can ask if true or if false, right? Right. So if Pcan is true, print that port X is open. Otherwise, we have no else statement here. So nothing else will run. So we'll only tell us if that port is open. So let's go ahead and save and run this. Python programming.net. Okay. And it's currently running. We don't really see anything occurring at the moment. Um, and really who knows how long this will take. Uh, in fact, let's go ahead and write a quick print. Um, it's usually like one second to port. So anyway, port X is closed. And then we'll add some exclamation marks to make this easy to see. Save over. Okay. Actually, we saw that port 22 is open right away. So let's let's run this one last time. And so port one is closed, port two is closed, port three is closed. So you can see it's it's very slow. And you know, we could run this through 65,000 ports uh per thing we're searching for. So, obviously, this is not uh the most efficient port scanner. Uh it's pretty poor. So, generally what people do is they will thread their port scanner. So, I thought it'd be kind of neat to show you guys our port 22 is open. Uh to show you guys a threaded port scanner. Um so, you can scan multiple ports at one time. So, that's the next thing I wanted to show you guys is a quick threaded port scanner and then we'll actually get back on our on our on the path of sockets and learn uh some more about sockets. So, anyways, uh stay tuned for that. As always, thanks for watching. Thanks for all the support and subscriptions and until next