Monthly Archives: October 2010

Verifying an SSL CA certificate

Whilst banging heads with an LDAP server recently, I needed a reliable way to verify that the SSL CA certificate I was using was the correct one for the certificate being returned by the server.

I came across this useful command after a search:

$ openssl s_client -connect ldap.example.com:636 \
    -CAfile /tmp/ca-bundle.crt -showcerts

This command will connect to the specific server and port (could be anything, in my case I’m using a secured LDAP server) and will use the specific certificate authority (/tmp/ca-bundle.crt) for verifying the certifcate returned by the server.

If the connection is established, it’s the correct/valid CA, if it doesn’t, the CA file is wrong and that’s probably why whatever you’re trying to debug is having issues connecting.

The other handy command I came across (thanks to SamatsWiki OpenSSL cheatsheet) is the following command which displays all the information, dates, stats, etc, relating to an ASCII format SSL certificate:

$ openssl x509 -in example.pem -noout -text

This is going to be a very handy command when I want to check when a certificate is going to expire without having to access the service itself to find out.

Day 25- What I would find in your bag

I tend to carry around a lot of stuff with me all the time – those who have met me IRL will know that I *always* have my laptop with me, no matter where I go.

I have managed to cut down on the amount of stuff, I have a separate bag I leave at the office that contains all my tools like SATA/IDE to USB adaptors, screwdrivers, crimping tools, cable ties, etc since I was getting too many to keep carrying about with me.

So the following is my bag – it’s from linux.conf.au 2010 which was held in Wellington – survived about a year of me so far, but will probably need replacing in another 8-12months time since it’s starting to break up in parts.

It’s a pretty good size for fitting in my laptop in one of the pockets as well as all the other bits I carry around, although I to tend to find that things just get jumbled together, more smaller compartments would be nice.

Would be great to have a bag that’s perfectly sized for my 12″ ultra light laptop, most bags I’ve found  are either too small, or designed for larger 15″ monstrosities.

Here’s what I’ve managed to fit into it:

Going from the top left, along, and down:

  • A5 drawing pad – I’m not much of a paper person, but using this a lot more these days for quickly sketching out application diagrams, user interfaces and other ideas as well as using for noting stuff whilst wandering around client sites providing IT support.
  • Vegan Wallet – Like most wallets, it contains money, cards and other junk. I’m not a huge fan of having it in my pocket,since my pockets are occupied with keys and phone.
  • Laptop – My Lenovo Thinkpad X201i 12″ ultralight laptop with extended 9cell long-life battery pack in it’s sexy lyra jumpsuit to keep it snug and protected.
  • Laptop PSU – tend not to use this so much, don’t really need to carry it around (I have one already on my desk at home and work) but the one time I don’t take it will be the time I need to charge my laptop on the go….
  • Three pens – cheap BIC, sharpie and more expensive BIC for sketching since I like the feel and line quality more.
  • CDROMs – sysrescuecd (a linux-based CLI live CD with lots of handy tools) and a Fedora 13 install DVD.
  • Cougar Protection
  • linux.conf.au branded screen wipe. Not that I ever actually clean my laptop screen as so politely pointed out by many people…. :-/
  • Cruddy Nokia mobile – have to carry this for one of my support contracts
  • Amberdms business cards
  • Plantronics Discovery 925 bluetooth headset in it’s docking/charging cradle. LOVE this headset, very crisp/clear, plus the fact it can pair to two phones or a phone and a laptop at the same time is brilliant.
  • USB cable for the headset charging. Which annoyingly is NOT a standard mini-USB cable. >:-(
  • Sunglasses and protective case. Kind of bulky and annoying to carry around, but summer is just starting and I’m allergic to light like any true geek.
  • Random trash
  • CNet USB bluetooth adaptor. I have no clue why I’m carrying this about.
  • ASUS USB 802.11g Wifi adaptor with Ralink chipset. I was carrying it when I was having problems with my laptop’s wifi since it works well with Linux, but not sure why it’s still in my bag now :-/
  • Key in plastic bag – I think this belongs to my mum’s luggage…. why I still have it, is a good question.
  • Spare key for my car on some long key chain.
  • Very cruddy old ethernet cable.
  • USB to serial adaptor, since I sometimes need to plug into networking gear with it and my laptop has no legacy ports anymore. :-(
  • 256MB USB drive on lanyard – use this as a boot drive, so often flash it with any boot image I need to do net/internet based Linux installs onto computers.
  • 4GB ADATA flash drive containing install files when delivering IT support.
  • 2 or 4GB flash drive from linux.conf.au which is used for random junk when I need it.
  • 8GB ADATA flash drive, used for sharing files with others when a network is not handy.
  • PS/2 to AT adaptor. I brought this when I needed it once for an ancient customer box. I’m really not sure why I’m still carrying it about, active machines with AT connectors are pretty damn rare these days.
  • Vodafone USB “vodem” (Huawei 3G modem). I technically don’t need this any more since my laptop now has built in 3G, but trying to splice the windows binary drivers to get it to work is proving to be a real PITA and I haven’t had the time to get the internal 3G to work yet. :-(
  • Lenovo ThinkPad Bluetooth Mouse – love this mouse, thought it might be a bit small originally, but it’s actually a great size, doesn’t suffer from interference/lag like some of the older RF mice, and being bluetooth, doesn’t require any additional adaptors plugged into my laptop wasting USB ports and power.

All together this is pretty much my life/office – when I travel, I add a NZ multiboard to it so I can charge all my devices and sometimes carry the spare 6-cell battery pack for my Lenovo.

Add my stereo or headphones and my model M and it’s pretty much all the assets that I own that I really care about.