It’s ramp-up-for-Defcon time, and for once there’s actually an AGENDA for tonight’s meeting!
No, it’s not written anywhere. It’s just in my head. But that’s still an improvement.
Managing changed SSH keys in CentOS 8
All these years, I’ve dealt with changed SSH keys (you know, you go to SSH into something and you get the “key has changed” error:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
probably because you rebuilt the target server/vm, or you changed an IP somewhere, or whatever) by removing the entry from ~/.ssh/known_hosts. It’s a few annoying extra steps, but it has always worked for me. Call it “old reliable.”
With the release of CentOS 8, everything changes. Known hosts are now managed by sss. Maybe this happened somewhere else and I wasn’t aware of it, but this is how I was made aware of it:
Message as above, along with:
Offending ED25519 key in /var/lib/sss/pubconf/known_hosts:6
Well that’s new. And you can’t delete from that file, because it’s generated behind the scenes and then comes right back. Generated from ~/.ssh/known_hosts, apparently. And nobody wants to enter a new key manually as it suggests. The answer?
ssh-keyscan -t ecdsa 10.120.x.x >> ~/.ssh/known_hosts
(substituting your target IP, of course). Almost worth aliasing “whoopsienewkey” to it with a variable for the IP.
Anyhow, that’s all, I hope you’ve learned something today to make your day easier and brighter.
Defcon28 Badge
Anybody interested in collaborating to investigate the Defcon 28 tape badge to uncover its secrets? Hit me up if you’ve got ideas and cycles.
Hackerspace Bookshelf…
The DC540 hackerspace just got a bookshelf. It’d be pretty cool if it had more titles on it that are relevant to this thing of ours. If you’ve got infosec, hacking, telephony, o’reilly books, etc., you no longer need, please consider donating.
DC540 hackerspace network infrastructure…
I’ve been working on infrastructure quite a bit lately. As a means of allowing people to become more involved in DC540 projects as they arise, I’ve been working on an authentication and information management infrastructure within the hackerspace. For example, I have Atlassian’s Jira and Confluence for collaboration, project management, and knowledge management, Bitbucket for code storage, and shared NFS file storage. The idea was originally that I’d be able to find some people willing to collab on projects, and the infrastructure would be there and ready for them. Since the pandemic has basically put the kibosh on in-person gatherings, I’m now working on opening that up to members via VPN.
I realize that not everyone has time to collab on projects, or even the interest. But when we find those that have the passion and availability to get involved in that way, it will be ready. I have enough information and projects of my own that it needs to be done anyway.
Users will be able to pound on the CTF vulnerable boxes, review and add documentation, upload 3d-printer files and schematics. I will try to integrate everything I have into the environment so there’ll be much to play with. Perhaps I’ll move the citadel into this environment as well.
Defcon 28 Tape Badge…
Of course you want one for your souvenir/swag/hacker fetish collection.
Maybe you haven’t bought one yet.
Maybe you want to know what it’s all about.
Maybe you don’t even OWN a fucking tape recorder in 2020.
You’re in luck.
KiCAD/FreeCAD free course
Did y’all see this?
https://www.eventbrite.com/e/hackadayu-kicad-freecad-tickets-109682641734?utm_source=Tindie+Community&utm_campaign=2db292f858-Community-July2020-1&utm_medium=email&utm_term=0_bb799798bb-2db292f858-87037781&mc_cid=2db292f858&mc_eid=7ed4a54b79
Hackaday U is offering a free KiCAD/FreeCAD course. Full course is four sessions, I’m signed up for what I hope is the first session Tuesday evening at 7. I figure it will mesh very nicely with the electronics course, since that course is mostly taught on Labcenter Proteus ($$$).
Meeting Notice
Monday’s check-in meeting is on at 6:30 at the following link:
https://zoom.us/j/819063060?pwd=b0wwUWtpRENkMGFiNUJQQW5pdVVJZz09
It’ll be limited to an hour, for me anyway, I have a rescue group board meeting at 7:30.
I can’t wait till this stupid pandemic is over.
Jumbotron images
LED Marquee kits are still available
Some of you newer members missed out on this, we picked up a bunch of parts to assemble kits to build this LED Marquee:
https://www.thingiverse.com/thing:2867294
for the December meeting, and we still have a few left. Includes case, Wemos D1 Mini microcomputer and LED matrix panels. Assembly and programming instructions are at that link. The 3d-printed case I settled on was white, and I went with red LED panels. It looks good.
If you’re interested in getting into IOT devices, it’s a great intro project. Not much soldering, good Arduino experience/introduction, etc. If you’re already into IOT stuff, it makes a great gift.
Cost is $15 per kit. Not doing shipping to keep the cost down, but we could meet up in the area and do a handoff. HMU up on twitter @dc540baab or email [email protected] if you want one.
Here’s what our kit looks like:
