Port Knocking in Action

tyldis writes "There was something called "port knocking" mentioned on Slashdot earlier, and now an implementation has sprung to life. Is this something worth pursuing?" The page is to an application called knockd which is a simple proof of concept with hard coded knock sequences. Really interesting stuff.

How do you transcribe...

[JesseL]

"shave and a haircut" into port numbers?

Re:Is this something worth persuing?

[Anonymous Coward]

Is pursuing something worth spelling correctly? also 'Yes'.

Knock Knock

[Anonymous Coward]

You can keep on knockin' but ya can't come in

Port to MIDI interface

[Black Art]

So how do we map musical notes to port numbers?

I want to get "shave and a haircut" ported over to the new protocol.

Re:How do you transcribe...

[winkydink]

I dunno. How many ports can you knock on with two bits?

old

[ozric99]

When the server detects a specific sequence of port-hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access.

pfft, XP has had this for ages....

Port knocking not exactly a new idea..

[morelife]

The port knocking idea is pretty old.. at least for months now all kinds of people are knocking my 135 1433 3127 and a bunch of others to DEATH, like hundreds a day, trying to get in..

Oops, that's Microsoft port knocking.. never mind, sorry, I guess it is new to Unix..

Knock Knock

[Anonymous Coward]

Who's there?

Packet.

Packet who?

Packet up bitch, you've been hacked.

If this box is rock'n...

[stephenisu]

Don't come a knockin'

Re:one of many

[Anonymous Coward]

Actually I counted 11 other port knocking implementations. Really I did. Can I get modded +4 also?

Re:How do you transcribe...

[nacturation]

I dunno. How many ports can you knock on with two bits?

Four, of course!

Re:one of many

[jacquesm]

port knocking is like having a deliberate hole in
your carefully constructed secure zone.

I'm going to stay a mile away from anything that
brings on board a 'knocker'...

I'd hate to get knocked up.

sounds like...

[beni1207]

is this at all related to fart knocking [neu.edu]? Because I spent a good deal of my time in jr. high school learning all about that....

Re:Port to MIDI interface

[Anonymous Coward]

The new chicken-powered iMacs [omlet.co.uk] have this already built in!

Re:Great for warez...

[gnu-generation-one]

"I can see this being used quite extensively in the warez arena."

Shhhh.... Don't mention the trojans.

Re:one of many

[PacoTaco]

Well, someone needs to come up with a better name. I feel like I should be saying "shut up Beavis" whenever somebody mentions it.

So how do you 'start' this?

[purduephotog]

Do you type:

>/etc/rc.d/rc3.d/s95Knock UP

?

So there I was

[ch-chuck]

I'd just scp'd a new file to my ISP, ssh'd in to edit index.html, checked email, and then when I refreshed the page in http, suddenly I has root access!

Re:Knock Knock

[Dorothy 86]

I knock, knock, knocked on that Gibson's door!

Re:How do you transcribe...

[Hanji]

$perl -e 'print join(",",unpack("s*","shave and a haircut"))."\n"'
29544,24950,25888,24942,25632,24 864,26721,26994,25461

Q-BASIC, BAH

Re:Secrets are not security

[Mr2cents]

<hypnotizing mode>Secrets are not security. Give me your pin code.</hypnotizing mode>

Re:Sniffing only works when on that network.

[Anonymous Coward]

Unless, of course, they've already installed a backdoor on your neighbor's unpatched windows box and are watching cable modem traffic on your subnet

Or "they" might have drugged your coffee, stole your keys, broke into your house, installed cameras everywhere, put a tap on your phone line, installed key loggers on your computer, ....

Re:Great for warez...

[Ctrl-Z]

Time to file a patent.

Security vs Obscurity

[surstrmming]

Most of you seem to miss the point. You do not get security through obscurity, but that does not mean obscurity isn't valuable in addition to security. It is.

Compare this to real life. You have a stack of porn magazines locked in a drawer. The security is the lock, preventing your mother from ever getting access to the porn. That's fine. But surely you would feel much better if your mother didn't even know there was porn in the drawer! That's obscurity. It doesn't make the lock any more secure, but it is useful.