Posts Tagged security

Security blows

I was about to post about how pleased I was with Synergy in helping me tidy up my desktop clutter (by removing a keyboard and mouse from the surface). Ironically, I’m instead posting about a problem with the configuration that will cause me to throw it out and look for something else. Why the title? Because the default configuration of a Linux distribution nowadays has given me no way to fix this ridiculously simple problem without powering off the running PC, VMware guests and all.

The problem is that Synergy and the VMware console don’t play well together (I could have sworn that when I first started using Synergy I had no trouble with it, but there are a few hits around that describe problems like I’ve now hit). The problems people are reporting are that keys like Shift and Ctrl are not passed to the VM (some described here and here).

My problem is slightly different: the screen of my Synergy client (the one that’s running VMware) locked while a VMware guest had focus. Now, the Shift and Ctrl keys are not picked up by gnome-screensaver to unlock the screen. Even the real keyboard attached directly via USB doesn’t work. Big problem, for the following reasons:

* Thanks to password strength rules enforced on the Linux build I use, my password now has a Shift-obtained punctuation character.
* I can’t switch to a virtual console, since that requires Ctrl (e.g. Ctrl-Alt-F1).

Okay, so the keyboard doesn’t work. This client machine just happens to be a tablet PC, and I had hacked gnome-screensaver (to display the onscreen keyboard to allow the screen to be unlocked in tablet mode). I grabbed the pen and tapped out my password, but it *still* didn’t work: even the output of the virtual keyboard gets the Shift modifier dropped. Hmm… Starting to fume now.

Never mind, I’ll connect via the network…

* Fedora does not start SSH by default (okay, yes, and I didn’t make sure it gets started after I’d finished the install).
* There is no remote desktop (VNC server, XDMCP) configured.
* The shiny web-based management interface on VMware Server 2.0 only listens on 127.0.0.1 (or is being blocked by the Fedora firewall).

So with no way to get access to the machine to try and fix it, a power-off is the only solution. Some readers are probably thinking “boo-hoo, diddums had to kill-switch his widdle poota, how tewwible,” but I hate having to do that; not because the system doesn’t recover, but it’s “problem resolution, Windows-style”.

Even though the real problem was between Synergy and VMware, I’m blaming the (perceived) need for security since without that I wouldn’t have a cryptic password that I can’t enter without Shift and a system I can’t administer over the network. Red Hat and Fedora doing everything in their power to ensure I don’t fall prey to nasty Internet fiends (rich analogies to governmental nannying, but that’s probably over-thinking things).

So in summary: Synergy is great, just as long as you’re not using VMware console and have a password with punctuation or uppercase… Remember to have your SSH or other network access enabled before you play!

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Active Directory accounts on Linux

Never thought I could get this excited about something to do with a Windows server!  But there it is — one of my SLES 9 test servers is now supporting logons from a user account stored in Active Directory, with no Samba in sight!

Before you say ANYTHING, this is not an indication that the Crossed Wires campus is switching to the evil side.  Any experienced Linux sysadmin will tell you that working with Windows systems can’t be avoided — and in some cases, welcomed (after all it’s better to have one or two Linux boxes in a sea of Windows than no Linux boxes at all).  My main customer at work is essentially a Windows shop, but their main file servers are Linux on zSeries, which means that me as a Linux guy needs to know more than I thought I would want to know about bringing Linux and Windows together.

So they are doing a migration to Microsoft Active Directory, and the Linux systems need to be integrated into the AD setup.  To our architects, Linux Windows integration equals Samba — they never bothered to look at making use of AD’s LDAP component to create a model that Linux can handle natively, instead of the (to me) less-than-optimal Winbind (don’t get me wrong, Winbind works, it just imposes some operational issues that I’d sooner do without, like SID-[UG]ID mapping, for instance).

So I proposed that the solution be updated to utilise LDAP, through the use of Microsoft’s own Services for Unix (SFU).  I was told “yeah, dunno why it wasn’t designed that way, would be the best way to do it, but no”.  Sigh.

So I decided to stick to my guns and set up something to show that it would work exactly as I said it would.  And I have!  I’ve worked around some inaccurate information on the ‘Net, some incomplete documentation from Microsoft, and some finger-checks on my part, to be able to show The Right Way to anyone who cares…  Yep, sometimes the useless thing is just worth doing.  :)

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Veejoe goes LDAP

We bit the bullet here at the new Ellendale data centre.  LDAP authentication!  Works like a bought one.

Coinciding with the relocation of the prime server from Rubicon DC to Ellendale DC, we’ve implemented LDAP authentication for Linux and Mac OS X clients.  There’s also automounted home directories to boot!  It went quite smoothly, all things considered.

Now will come the dreaded data reorganisation (there’s about 1.5TB of storage across all the Crossed Wires machines).  Also, I’ve been running Samba 3 for a while so there’s probably not much reason to keep putting off integrating the Windows boxes into LDAP as well…

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