Ralf’s Blog

I’m now using Mac OS X since 1,5 years, and something that I always wanted to be able to do is to quickly open another Finder window that shows the same path as another one.

Today I discovered how to do this (not exactly obvious, if you ask me!), and here’s how…

Press Cmd-N to open a new window. With the new window being active, click Cmd-Shift-G to open the “Go to the folder” prompt. Press BkSpc to clear the prefilled content. Now activate the window that you would like to “clone.” Click-drag the Folder symbol in the title bar and drag it into the “Go to the folder” prompt. Click “Go” or press Return.

Presto! You cloned your original Finder window.

If you know more hints like this, please do post them here!

Two months or so I ordered the Snow Leopard DVD for my Macbook Pro. Finally I had the time to perform the upgrade from Leopard. Before actually doing so, I tried to create a disk image of my current Leopard installation. So I booted the Snow Leopard DVD and ran “Disk Utility” from it. Because the target of that disk image was an external hard drive shared by my team, I wanted to create an encrypted image.

Regardless of whether I selected “128-Bit AES” or “256-Bit AES” as an encryption method, I immediately received the following error message on screen:

Unable to create "Macintosh HD.dmg" (Cannot allocate memory)

What is this trying to tell me? No space on hard drive? Impossible, since the external hard drive is a 2 TB empty drive. Moreover, “memory” usually refers to “main memory”, or “RAM.” So is Disk Utility actually trying to read the whole 200 GB hard drive into the RAM, then encrypting it, and then creating the disk image from it?! I can’t believe that anyone would be that stupid to design a disk imaging program like this…

I finally changed the image format to “Compressed”, and presto, it worked!

Anyway, why, oh why is it so hard to generate “user friendly” error messages? And why does this happen under Mac OS X of all operating systems, supposedly being the “user friendliest” OS in the universe?

This is not the first time I receive such useless error messages in OS X. Hey Apple, care to finally make your homework???

I recently stumbled across a problem with Mac OS X Leopard’s “svn” (Subversion) client which doesn’t know about common root CAs (such as Thawte in my case,) even tho they are in the system keychain (which you can view using “Keychain Access.”)

It turned out that it only uses the certificates it find in /System/Library/OpenSSL/certs.

The strange thing is that the Thawte certificate in fact is already present on Mac OS, but it’s inside /usr/share/curl/curl-ca-bundle.crt, which svn doesn’t know about. So what I did to make it work is the following:

I extracted the certificate from /usr/share/curl/curl-ca-bundle.crt and copied it to /tmp/thawte.pem. I then determined the hash of the certificate as follows and created a link to the original certificate bundle (as superuser!):

#openssl x509 -in /tmp/thawte.pem -noout -hash
ddc328ff
#ln -s /usr/share/curl/curl-ca-bundle.crt /System/Library/OpenSSL/certs/ddc328ff.0

Voilà! Now I could connect to our Subversion repository without receiving a warning like the following:

Error validating server certificate for 'https://our.repos.de:443':
- The certificate is not issued by a trusted authority. Use the
fingerprint to validate the certificate manually!

I just had another annoying problem with my MacBook Pro 4.1, running Mac OS X 10.5.6.

I left the machine unattended for like 10 minutes or so, and when I came back the screensaver was active. Sliding a finger over the trackpad wouldn’t produce the log-on dialog, nor would pressing keys on the internal keyboard. The machine was not crashed, however, since the screensaver animation was still running. What was even more strange is that the “Power on/off” button would work — when I shortly pressed it, the log-on prompt would appear.

Fortunately my view fell upon an external USB mouse, which I immediately tried. Voilà! I could move the mouse pointer with the external mouse, but the trackpad and internal keyboard were still dead.

I then attached an external keyboard, and that one also worked.

Back in Mac OS X I stopped all running applications, and restarted the MBP. Afterwards, all was fine again.

What the heck is this??? I thought Mac OS X was famous for its stability and reliability?! Is that what makes it “superior to Windoze” (according to a considerable fraction of Mac users)???

I had a VIDEO_TS folder with VOB files that I wanted to burn to a DVD in order to be able to play it on our DVD player.

The first step was to create an ISO image. This can be done with a tool that comes with MacOS. Open a terminal and enter the following:

hdiutil makehybrid -udf -udf-volume-name "<volume name>" -o /target/image.iso \
    /path/to/parent/folder/

Make sure you specify the folder that contains the VIDEO_TS folder as the source folder in the above command line. Parallel to the VIDEO_TS folder you should also have an (empty) AUDIO_TS folder. Also make sure that there is no .DS_Store file (remove from terminal if present.) And note that the above is one logical line (the \ is a line break).

So, how do you write the ISO file to a DVD? (more…)

I suddenly had a problem on my Mac that I couldn’t start the VPN client anymore — “Error 51″ was the only thing I received.

Google pointed me to this site where I found some very helpful advice.

Thanks!

As a new Mac user I find it very annoying that the Finder leaves its traces everywhere you go — even on USB sticks.

The finder will create hidden .DS_Store and .Trashes folders (used by SpotLight and the Trashcan) all over the place.

I’ve not yet found a way of disabling this unwanted behavior.

If you know of a way to do so, I definitely want to hear from you. So, please step ahead and leave a comment!

Mac OS normally doesn’t allow you to use network shares as targets for TimeMachine backups. This can be worked around, tho.

First you need to tweak Mac OS to accept network shares by entering the following command in a Terminal session:

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

That would already allow you to store your backups on a network share. But do you really want to trust your valuable data to a network share that can potentially be accessed by untrusted users, such as your favorite bastard admin from hell?!

Here’s when the following comes in:

You will create an encrypted sparse bundle and use it as a target for the backup.

(more…)

I was pointed by a colleague that ARDAgent can be exploited locally to gain “root” privileges under MacOS 10.4 and 10.5. A quick search on Google turned up this post on Macworld that gives some details about this issue.

To check whether you’re vulnerable type the following in a Terminal window:

osascript -e 'tell app "ARDAgent" to do shell script "whoami"';

And if it says root you are vulnerable. To quickly protect you type the following:

sudo chmod u-s /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAgent

I was very happy to see that there’s TrueCrypt for the Mac, a disk encryption tool I really like and use since a long time on my Windoze PC.

Quickly I installed it. The installation went smoothly, and a quick test was successful. However, when I played some more with it, I found a strange oddity which I couldn’t clarify myself. I doubt that it’s because I’m a new Mac user, but I rather think it’s a quirk in TrueCrypt. Let’s see whether anyone can reproduce the issue, and whether it will be fixed (shortly).

Anyway, this is a tool that you should definitely use when you have confidential data on your laptop.