Installing openSUSE Leap 15.1 into a MacBook Pro with encrypted root drive
Thursday, August 15. 2019
I happen to have a spare 3rd generation 15" MBP. It is late 2013 model, used for years but recently just gathering dust. Back in the days, when the laptop was shiny and new, it was a serious piece of hardware and cost north of 2000 €. Even today, a fully working second hand 15" late 2013 would be priced around 25% of the original value. Couple years later Apple started manufacturing MBPs with faulty keyboards, faulty touch bar (the really weird top row) and faulty batteries. I'm in luck, as my unit pre-dates all of those. Yes, there are also some fatures missing which I'd love to have, fingerprint reader, USB-C -port and improved display to mention the most important ones.
Since the dust-gathering, I decided to see how a fresh Linux installation would go. Back in the days, I had a plastic MacBook running Linux. Given 32-bits and not-so-powerful CPU, I recycled it at the point I got tired of waiting for pages to load too long on Firefox. The amount of JavaScript modern web pages run is staggering. All that requires huge amounts of CPU to parse, process and run. Old low-end models simply won't cope making web browsing nearly impossible. So, I didn't have a Linux-Mac for couple years and now I wanted one.
Known facts
This I could figure out before doing any real installing:
- Installation can be done. openSUSE docs describe the process @ https://en.opensuse.org/SDB:Installation_on_a_Mac
- The built-in Broadcom WiFi isn't properly supported by most Linuxes, that includes openSUSE
- Debian Linux wiki @ https://wiki.debian.org/MacBook/Wireless states:
"MacBooks before the late 2008 models use Atheros chipsets, while late 2008 are now using Broadcom 4322 chipset." - StackExchange article @ https://unix.stackexchange.com/a/175813/241396:
"Broadcom 4360 actually comes with either of two distinct chips, 14E4:4360 and 14E4:43A0. There is no driver in Linux for the first one, while wl is an appropriate driver for the second one." - Arc Linux wiki @ https://wiki.archlinux.org/index.php/broadcom_wireless#broadcom-wl only states the fact wl-driver not being open-source.
- It is unclear which exact chipset is in the Mac, but it seems not to be properly supported in Linux.
- Debian Linux wiki @ https://wiki.debian.org/MacBook/Wireless states:
- My MBP doesn't have Ethernet RJ-45 port
- The existing USB-ports or Thunderbolt-ports could be used to host a network adapter, either wired or wireless, but I choose not to go down that path. Having an USB-dongle stick out of the Mac isn't something I'm willing to do.
- There is a good chance, that a Linux-driver for the built-in Broadcom WiFi exists. The existing driver can be downloaded from the net, but require some trickery to install during openSUSE installer.
- In macOS, drives are encrypted. In Windows using BitLocker is a good option to keep your data secure. Linux supports drive encryption as well.
Prerequisites
- A MacBook Pro with SSD full of data you don't care about. Also emptied SSD-drives will do.
- openSUSE Leap 15.1 ISO-image from https://www.opensuse.org/
- I personally will go for the full DVD, but it is not absolutely necessary. Small network installer will work as well.
- Skills to create a bootable USB-stick from the install image
- Your wireless network credentials and skills to connect a new device into it
- Two USB-sticks:
- One to boot openSUSE installer from. This stick will contain installation image and cannot be easily written into and must be attached to the Mac during installation.
- Second to transfer the WiFi-driver files
- Broadcom Linux wl-driver from http://download.opensuse.org/repositories/home:/Sauerland:/hardware/openSUSE_Leap_15.1/x86_64/
- Installer will need file
broadcom-wl-kmp-default-6.30.223.271_k4.12.14_lp151.27-lp151.121.1.x86_64.rpm. - Store the file into the second USB-stick.
- Installer will need file
- Since kernel-default -package has an update, the above RPMs needed for installer won't work in your installed openSUSE. To fix this, you will need also Broadcom Linux wl-driver from http://download.opensuse.org/repositories/home:/Sauerland:/hardware/openSUSE_Leap_15.1_Update/x86_64/
- Your installed openSUSE will need two files
broadcom-wl-6.30.223.271-lp151.121.4.x86_64.rpmandbroadcom-wl-kmp-default-6.30.223.271_k4.12.14_lp151.28.10-lp151.121.4.x86_64.rpm. - Store these files into the second USB-stick.
- Your installed openSUSE will need two files
- To make your life easier, having access to another computer while doing the install will help the process greatly. Especially, if you need to get a newer version of the Broadcom-drivers.
- That's it!
Disclaimer for RPM-files:
Those versions of files are valid at the time of writing. Both the install ISO and installed & updated openSUSE Linux are likely to eventually get updated and the versions of those files WILL change. Keep reading! There are instructions for you on how to compensate for updated versions. However, download locations will not change for openSUSE 15.1. The locations won't be valid for 15.2, but I'm sure you got that already.
Step 1: Prepare openSUSE 15.1 install
As instructed in https://en.opensuse.org/SDB:Installation_on_a_Mac, copy the installer ISO-file to the USB-stick. On macOS and Linux, figuring out the exact output drive can be bit tricky, so be careful with that. On Windows, the best utility for USB-drives is Rufus. You can get it from https://rufus.ie/.
While at it, download the required driver from above URLs pointing to Sauerland repository. Both versions are eventually needed, so just download them.
Note: for installer, only broadcom-wl-kmp-default -package is needed. We can safely ignore any RPM dependencies, as it is not possible to actually install the package. For installed Linux both files are needed, they have a dependency between packages. More about that when you're actually tinkering with the files.
Step 2: Boot the Mac into openSUSE installer
Plug in the installer USB (the other USB isn't needed yet). Power up the Mac. When you hear the boot-sound, press and hold the Alt/option-key. When you see the boot-menu, you can release the key. Displayed on your screen, there is a boot drive selection menu:
Go for the USB UEFI, that will start openSUSE installer.
Old geezers like me will remember the times when Macs required special bootloaders and tons of tinkering just to get the USB-boot to work. For past years, thanks to UEFI, USB-booting a Mac isn't any different than booting a PC.
Step 3: Establish facts
When the graphical installer launches, you'll see the license agreement screen:
On top-right corner of that screen is also keyboard map choice. This is your chance to make sure your keys will work correctly on the GUI. This won't affect the text-console.
Switch to text-mode console
There are two critical pieces of information needing to be confirmed to get the WiFi-driver working. Since the openSUSE installer is running in graphical mode, you need to switch to text-mode. In a Linux, the console can be chosen with Alt-<function key> -combo. When graphical interface is running, key combo is Ctrl-Alt-<function key>. To make things even trickier, in a Mac <function key>s require the actual Fn-key to be pressed, so ultimately you'll need to press and hold Fn-Ctrl-Alt and then tap F2-key to go for a text-console.
Confirm kernel version
On a bash-prompt, check the exact Linux kernel version with a:
cat /proc/version
As a result, my install image will display:
Linux version 4.12.14-lp151.27-default
In Linux, all device modules are stamped with the specific kernel version they'll work with, so it is imperative to get the Broadcom driver for that exact kernel version.
Confirm broadcom WiFi hardware
On a bash-prompt, get a listing for wireless network devices. List PCI-devices with class 280, that's for all network controllers (listing is at https://pci-ids.ucw.cz/read/PD/), as already established, there shouldn't be too many of those:
lspci -d '::280' -vv -n
On my Mac, the response is:
02:00.0 0280: 14e4:43a0 (rev 03)
Remember from above: "Broadcom 4360 actually comes with either of two distinct chips, 14E4:4360 and 14E4:43A0. There is no driver in Linux for the first one, while wl is an appropriate driver for the second one." So, this is the confirmation we needed. wl is the driver needed and we can move forward with installing the driver.
Step 4: Install the Broadcom driver
This screenshot depicts my process:
Now that you know the kernel version (4.12.14_lp151.27 in my installer) and copied the downloaded RPMs into the other USB-stick, plug it in. Remember: the installer USB is needed and cannot be removed.
Determine the correct device and mount it
In the above screenhot, the USB-stick having the drivers is /dev/sdb. First I checked out which storage devices Linux found. There are number of those for: Apple SSD, installer USB and driver USB. Since I knew, my driver USB is a Kingston Datatraveller, displaying the block-device partition table by running parted /dev/sdb print helped to identify the correct drive.
I mounted the USB-stick with a:
mkdir /tmp/usb
mount /dev/sdb1 /tmp/usb
Locate the files from the USB-stick.
Unpack the driver RPM
At this point, the Broadcom RPMs versioned for openSUSE installer kernel need to be popped open. The ones for your running Linux will install as-is, so no need to unpack them. It would be easy & smart to just install the RPM, but given Linux installer, it is not possible. Most of the mounted filesystems in an installer are SquashFS filesystems (more info from https://en.wikipedia.org/wiki/SquashFS) and are read-only. Well... you CAN alter a SquashFS, but it is more complicated than just running couple commands to extract the driver from RPM and injecting it into a running system.
To unpack an RPM, in a temporary directory run following (this is a single-liner, I just wrapped it into two lines for readability):
rpm2cpio broadcom-wl-kmp-default-6.30.223.271_k4.12.14_lp151.27-lp151.121.1.x86_64.rpm \
| cpio -ivd
This will create any subdirectories and files into the current directory where cpio-command is run. That's why a temporary location is suggested.
Install wl-driver
As already established, Broadcom on Linux is a messy business. And this Broadcom chip in your MBP is especially messed up. So beware! Trickery ahead.
The other file you won't be needing during installation, but you will for your running openSUSE would contain a file etc/modprobe.d/50-broadcom-wl-blacklist.conf. This blacklisting mechanism exists in Linux to prevent device-modules from being loaded when a particular device is being used. Now, at the point you're running the commands on your Linux-installer its too late. Your installer already loaded bunch of device drivers you won't be needing. So, they must go. Contents of the file suggests what to remove:
# modules blacklisted for broadcom-wl
blacklist bcm43xx
blacklist ssb
blacklist b43
blacklist ndiswrapper
blacklist brcm80211
blacklist bcma
blacklist brcmsmac
You can run command rmmod for each of those, but I choose to go for a for-loop:
for module in bcm43xx ssb b43 ndiswrapper brcm80211 bcma brcmsmac; do
rmmod $module
done
In my Mac, at least modules b43, ssb and bcma were loaded.
Warning: If you DON'T rmmod conflicting modules, your wl-module will NOT work.
Finally, it's time to go for the good driver. When you unpacked the driver RPM, it contains a subdirectory. My driver is at lib/modules/4.12.14-lp151.27-default/updates. Go there and run:
insmod wl.ko
There is zero feedback for your command. To get an indication of success, run iwconfig. It will display something like:
wlan0 IEEE 802.11 ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=200 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
When you see an existing wlan0, you're golden! Now you're good to go forward with graphical installer.
Step 5: Install openSUSE Leap 15.1
First, go back to graphical installer. The key combination for that is:
Press and hold Fn-Alt and then tap F7-key
Add your Mac's Broadcom to Linux
In the graphical installer, go Next from license screen and witness a blank Network Settings screen. The installer wasn't able to determine any operational network interfaces in your system. Not to worry, now that your Broadcom is on-line, you can add it. Click Add, and add a Wireless device using Kernel module wl:
Moving forward with Wireless Network Card Configuration, a screen to connect to your WiFi will appear:
Scanning for any available networks will provide you a drop-list of found networks. Your own network needs to be in that list. Just add your authentication details to the dialog and you're good to go.
Instruct openSUSE installer to encrypt your root drive
(This is completely optional, you don't NEED to have an encrypted hard-drive. I just love doing stuff like this.) When your installer wizard will reach Suggested Partitioning, that's your cue. Going for encrypted root partition is actually surprisingly easy on openSUSE:
Go to Expert Partitioner using the suggested partition as a baseline for your custom partitioning. The only thing you need to change is to enable encryption on your root partition. Find mount point / and Edit it. Just click Encrypt Device and choose a wise password for your encryption. That's it. Then you can Accept the partition plan and move forward.
Add an user to new Linux
For security reasons, I'll always separate my administrators and regular users. What level of security you're targeting for is completely up to you. I, personally won't use Automatic Login and won't use same passwords for super-user and regular users. The Local Users dialog will look like this:
Hang tight, you're almost there.
Install!
When you reach the Installation Settings, you're about to start destroying any previous data on your Mac and start installing the Linux:
Enabling SSH and drilling a hole for it into firewall is up to you. Also, the choice of tooling for network management is up to you. I do dislike NetworkManager and obviously choose to drop it and go with wicked. If you want to learn more, go read wicked FAQ at https://github.com/openSUSE/wicked/wiki/FAQ.
When you click Install in the Confirm Installation -dialog, the ball starts rolling. If you missed the previous warning, before this point your data is still intact in the drive, after this point it won't be anymore. This is the part where you can go grab a cup of coffee:
At the successful end, your system will automatically reboot. When the installer reboots the computer, you can remove the installer USB. It won't be needed anymore.
Step 6: Reboot into your newly installed Linux
If you went with encrypted partition, GRUB will require the password to decrypt the drive to load Linux kernel:
Hint: If you already didn't, just yank out the installer USB.
The "funny" thing about encrypted root partition is: when your kernel is loaded by GRUB, kernel will need the same password again!
Yes, punch in the same password again to reach login-screen.
Add your Mac's Broadcom to Linux - Again!
Once logged in all the hard work you did with the Broadcom-driver are lost. Your newly installed openSUSE will NOT have the Broadcom-driver installed. What! What! What?
But wait! This time installing is much easier. You actually CAN simply install the RPMs from the other USB-stick. On an installed Linux, the system can be written into.
Confirm the kernel version (again) and notice how it is different. My system has:
Linux version 4.12.14-lp151.28.10-default
Just like before, figure out which one the device is (with a great likelihood, it is not the same device anymore) and mount it. Once mounted, as root you can do something like:
rpm --install -h *.rpm
Installing the RPMs won't make your network operational. In a Linux, there are always ways to avoid rebooting, but in this instance I found it simply easier to go the Windows-way and reboot. You can do that at this point. Alternatively if you don't just yet need a network, you can also remove the second query for encryption password and then reboot to fix two problems on a single reboot.
Remove the 2nd password prompt
This is something I wouldn't do on a shared machine. Since I'm almost certain, nobody else will use my laptop, in this instance I'm willing to add ease of use with cost of potentially losing my security. If a logged-in user can access the encryption key-file, my encryption security is gone! Before allowing a second encryption key to be used, the plain-text password is not stored anywhere. To keep my system still secure, I need to make sure the permissions for the file are correctly set and also keep any malware or unwanted software from stealing my precious key-file.
Process for setting up encrypted root in openSUSE is described well in https://en.opensuse.org/SDB:Encrypted_root_file_system. As instructed there, create a keyfile, add the keyfile as a valid key into LUKS and secure the setup:
For relaxing my system's security, the general idea is to load some random bytes from /dev/urandom and create a random-content key-file. The docs are using 1024 bytes, I went double that for a 2048 byte keyfile. In my sequence, I first create an empty file, then lock all other users out of it and then populate the file with random bytes:
touch /.partition.35d5293d-6fe0-4eaf-987f-4f2eca8ca6d7.key
chmod 600 /.partition.35d5293d-6fe0-4eaf-987f-4f2eca8ca6d7.key
dd if=/dev/urandom \
/.partition.35d5293d-6fe0-4eaf-987f-4f2eca8ca6d7.key \
bs=1024 count=2
Then this newly created filename needs to be added into two places. First /etc/crypttab. After setup, there are only two columns. As instructed in the documentation, a third column needs to be added. Note: This single line having three columns is split into three lines here for readability. If you fail to have this as a single line, your system will fail to reboot:
cr_ata-APPLE_SSD_SM0256F_S1K4NYBF401257-part3
UUID=7e49a147-b626-41cc-bc89-49e8a13b9cb0
/.partition.35d5293d-6fe0-4eaf-987f-4f2eca8ca6d7.key
Second into initRD by creating a new Dracut configuration segment /etc/dracut.conf.d/99-root-key.conf:
echo -e 'install_items+=" /.partition.35d5293d-6fe0-4eaf-987f-4f2eca8ca6d7.key "' \
| sudo tee --append /etc/dracut.conf.d/99-root-key.conf
Yet again, to keep your system secure, make sure nobody else can access your /boot-stuff:
chmod -R go= /boot/
To have this Dracut segment have any effect, you need to run mkinitrd as root. If you want more information about initRDs or Dracut, go to https://dracut.wiki.kernel.org/.
Now, you're ready to reboot the Linux. Both WiFi and password setups are done.
Step 7: Reboot and verify setup
You will need to enter the encryption password for GRUB, no change there. However, your Linux should go directly to login-screen. If it doesn't, you failed somewhere.
Also, after a login, your WiFi should work. To confirm, go to a prompt:
Since installer saved your wireless connection details, now you have network connectivity also in your installed Linux!
Step 8: Finalize
Remember the part where your installer used a different version of Linux kernel than your ready system? Kinda hard to not remember it, right. Now some additional work is needed to keep your system working:
As root, run this in a bash-prompt (again, a single-liner):
zypper addrepo \
https://download.opensuse.org/repositories/home:Sauerland/openSUSE_Leap_15.1_Update/home:Sauerland.repo
The setup information is available at https://software.opensuse.org/download.html?project=home%3ASauerland&package=broadcom-wl.
Finally: Go to YaST2 and use the GUI to inspect all the software repositories your system has. It must have Sauerland's repo enabled for the Broadcom driver to get updates as openSUSE's kernel-default -package does.
Step last: All done
That's it. Now your Mac is successfully running an openSUSE 15.1 Leap Linux.
Enjoy!
Let's Encrypt ISRG's Root - Fedora curl fix, part 2 - Shared System Certificates
Thursday, August 8. 2019
Let's Encrypt ISRG's Root - Fedora curl fix
Wednesday, August 7. 2019
Update 8th Aug 2019:
The information in this blog post is not the entire truth and less accurate, than I'd hope for. Updated information regarding certificate system in a Fedora linux can be found from this blog post.
Now that Let's Encrypt is issuing their certificates from ISRG Root X1 / Let's Encrypt Authority X3 certificate authority, my Fedora is failing to access sites with curl. I have addressed both of these earlier in articles Let's Encrypt Transitioning to ISRG's Root and Fixing curl with Go Daddy Secure Certificate Authority G2 CA root. However, the previous fixing instructions in modern curl won't work. This is because Fedora guys won't build curl with NSS anymore, but have fallen back to standard OpenSSL used by almost everything else in Linux. Since I'm writing about it, they're doing a bad job about it.
If you'll never use curl or anything built with libcurl, you'll never notice anything. Also, if you're running curl/libcurl but are never accessing any sites with Let's Encrypt certificates, again, you won't notice it. Most of us will notice. Curl will keep spewing errors like "curl: (60) SSL certificate problem: unable to get local issuer certificate" making everybody mad.
Unlike earlier, curl run with --verbose will announce following certificate locations:
* successfully set certificate verify locations:
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
It so happens, the new intermediate certificate used by Let's Encrypt isn't in the precious ca-bundle.crt file, your connection attempts will fail on a trust issue. You can run the classic OpenSSL certificate fix -operation:
# cd /etc/pki/tls/certs
# wget https://letsencrypt.org/certs/letsencryptauthorityx3.pem.txt
# mv letsencryptauthorityx3.pem.txt letsencryptauthorityx3.pem
# openssl rehash
... which will fix a lot in your Fedora, but it won't fix curl. Remember: it will only look inside the /etc/pki/tls/certs/ca-bundle.crt, and you did not add it there.
To get the issue solved for realz, you need to delete the symlink pointing to the certificate bundle file, cook up a new & better one. Like this:
# cd /etc/pki/tls/certs
# rm -f ca-bundle.crt
# cat /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem /tmp/letsencryptauthorityx3.pem > ca-bundle.crt
Now your curl will be tamed. But it won't stick. The first time you'll get an update to RPM-package ca-certificates, your changes are gone and you'll need to re-do them. Gee! Thanks for that.
Bug report is at Curl not using CA-path - custom certificates not used. Go add your comments there to let Fedora guys know how much you appreciate their work! 
Zebex Z-3151HS bar code reader - Windows 10 - Unknown USB, USB device not recognized
Thursday, July 11. 2019
Among the number of toys I have, are couple of Zebex bar code readers. Since forever (or 2013), I've had issues with Windows not detecting the newly attached USB-device correctly. See my previous article Windows 7 unable to detect a HID barcode scanner for details. That was on a Zebex Z-3000 to be exact.
During all these years, the problem has not solved itself and all my attempts to fix have been not-so-successful. The reader I've been most recently used is an improved one using a laser to read the data, a Z-3151HS (the HS stands for High Speed). The version query will return a single-line string containing following:
Model Z3151HS S01.01
Ver
01.27
Date
01-18-2019
On a plugin, the USB human-interface-device (or HID, or keyboard) does this:
Nobody loves seeing an USB device not recognized -popup, or Device Descriptor Request Failed on device manager. That's a sign of a major malfunction.
Luckily, in this case without spending too much time, little bit of troubleshooting became fruitful and both problem reason and a fix were found. The bar code reader loves being in a wrong mode. This is an USB-device, but no matter what I try, on plugin the device will be in IBM PC/AT/PS/2 Keyboard emulation mode. That incorrect mode makes the newly plugged in USB-device not respond to a Windows intiated device query. As you might think, your Windows will be pissed about the failure and bark about it. Obviously, the device should be in USB-mode to handshake properly with Windows, that's a no-brainer.
Again, the mode can be changed easily by scanning some bar codes (these are actually in the manual too):
Enter configuration mode, switch to USB-mode and end configuration mode. Poof! Now Windows 10 sees the HID USB-thingie ok and it does work correctly. The obvious problem is, that you really do need to do it EVERY SINGLE TIME you plugin the device to your computer. Not cool! Numerous attempts to fix the mode-select have failed. If you have a suggestion, I'd be happy to try it.
Bonus: Firmware upgrade
My unit had a measly 1.03 firmware when I bought it. Obviously, I've been upgrading firmwares while hoping the problem would be solved somehow. No such joy yet.
New firmwares can be downloaded from Zebex website @ https://www.zebex.com/en/product/index/20/Z-3151HS with appropriate tooling to do the update. Since this is on a computer, nothing will ever work as smoothly as you'd like. On an attempt to run the firmware upgrade tool, this will happen:
In front of your eyes, a failure will occur and a message will state: Make sure the device work under USB-Boot mode. I'm not sure whose English grammar is better, mine or that person who wrote that sentence, but the problem stands. You need to get your device into USB-Boot -mode and you have zero clue on how to do that.
Tons of googling, reading forum posts and manuals will reveal, that such a sequence does exist. You need to scan following bar codes:
Yet again, go for configuration mode, and place the device into USB update -mode. After that, your firmware update will proceed to actual update.
I'll hope these tips will help some poor user trying to get his/hers reader working.
Enjoy scanning!
Weather Station destroyed in hailstorm
Wednesday, July 10. 2019
Over four years ago I wrote about my weather station setup. Well ... It doesn't exist anymore. There was a severe thunderstorm and my gadgets weren't properly fastened to the steel pipe and this happened:
After weather cleared, I realized the lack of readings from my garage roof. The poor temperature unit / CPU was upside down, hanging from some wirings and FULL OF WATER! Ufff! Electronics and water won't mix. At least not well.
My zip-ties didn't like the ping pong -ball sized hail:
The picture from sunroofing is from my friend's place. He has some tinkering to do, to get this deck roofing fixed. That piece of plastic didn't survive chunks of ice plummeting from the sky.
To get my weather properly measured and data-logged, I already put a purchase order for a new unit. This time I'm going for a Davis Vantage Vue. Also, to save money this time I'm attaching it properly!
Weather Station destroyed in hailstorm
Wednesday, July 10. 2019
Over four years ago I wrote about my weather station setup. Well ... It doesn't exist anymore. There was a severe thunderstorm and my gadgets weren't properly fastened to the steel pipe and this happened:
After weather cleared, I realized the lack of readings from my garage roof. The poor temperature unit / CPU was upside down, hanging from some wirings and FULL OF WATER! Ufff! Electronics and water won't mix. At least not well.
My zip-ties didn't like the ping pong -ball sized hail:
The picture from sunroofing is from my friend's place. He has some tinkering to do, to get this deck roofing fixed. That piece of plastic didn't survive chunks of ice plummeting from the sky.
To get my weather properly measured and data-logged, I already put a purchase order for a new unit. This time I'm going for a Davis Vantage Vue. Also, to save money this time I'm attaching it properly using steel hose clamps!
Azure Developer Associate certification
Thursday, June 27. 2019
Yup.
Passed that one yesterday. For those intersted, it was a AZ-203: Developing Solutions for Microsoft Azure exam.
Previous one was 21 years ago:
Notice how they misspelled my name. Argh!
I bet many of you haven't used Windows NT4.0 Workstation for a while (or ever).
Also notice how the certification was issued by Mr. Bill Gates himself!
EBN European Business Number scam - Part 4 - Epic win!!
Tuesday, June 25. 2019
Couple weeks ago, a good friend of this blog, Mr. Gorila approached with his comment (available at https://blog.hqcodeshop.fi/archives/372-comments.html#c2786). He suggested, that our beloved friends at DAD Gmbh were in some sort of financial trouble. I did some digging of my own, but given the huge handicap of me not knowing any German language nor corporate laws or practices of Germany, I found nothing. Today, Mr. Gorila approached me again with proof.
EBN scammers are Bankrupt!
Its obvious, that the people behind the scam went nowhere. They're still there and are cooking up something while trying to maintain the scam from Cyprus. There are comments from people, who received letters from debt collectors operating from Cyprus. The "debt" in question is from EBN scam and is somehow transferred from DAD Gmbh to CLB Solutions Management.
Regardless of these events, my advice is unchanged: Keep your cool and
DO NOT PAY!
There seems to be increasing amounts of proof of malpractice by DAD Gmbh. Their "debts" are completely ficticious and there is no way they can win anybody in a court of law in Germany. They need to sue your ass in Germany court, and that's there they will lose. They already did that and will keep losing. Actually, "they" don't even manage the company anymore. The company is to be dissolved by court order and liquidation is handled by somebody else than the scammers.
Proof
For those wanting to see the proof, go to https://www.bundesanzeiger.de/ and make a search for "DAD Deutscher Adressdienst". You will receive search result page:
The first result will be the official notification of company liquidation. If you click the link, the text simply says the company will be dissolved and all creditors should contact the company.
More interesting is their balance sheet from year 2017 (printed into PDF by me DAD-scam-Bundesanzeiger-DAD-balance-sheet-2017.pdf). That piece of criminal history needs to stay available as long as there is Internet and human life on Earth.
My most important findings are:
- Scammers have almost 1 million € in accounts receivable. That's ficticious "debt" from marks they scammed.
- Its obvious, that majority of that "income" will never land at their bank accounts. DO NOT PAY!
- Company has nearly 250.000 € cash available
- Two options here: Their liquidation hit them as a surprise or they are really bad at crime.
- It makes no sense to leave any easy-to-move assets to the company.
- Besides the 25.000 € initial capital, that's the profit from their crime. I imagined more.
- Their accumulated operating loss is nearly 100.000 €
- I don't think they ever targeted for profit.
- In a company, it is very easy to avoid taxes by never making any profit out of the operation.
- Stated in balance sheet details: There are almost 400.000€ liabilities remaining
- Given the coarse nature of a balance sheet, I cannot deduce much from that besides they owe more money than they have.
- That kinda explains the liquidation.
Future
They're already running a new scam. It's called European Register of Commerence or ERC. The webpage looks like this:
Its simply a spin-off from EBN-scam with a GDPR-twist.
Participate!
Anybody of you can participate in fighting these scammers. I'm maintaining the Finnish Wikipedia page for EBN scam to have a reputable source of information available with a really good Google page rank. Page is at: https://fi.wikipedia.org/wiki/European_Business_Number
You can do the same in your language!
Keep people informed about these scams. That will make the work for those scammers harder and harder. Many readers have shared information in comments of my blog, please keep doing that! There are people including me, who will investigate your clues and raise awareness of these scams and what happens in the scam'osphere.
Thank you!
Trigger Azure CDN to update certificate to custom domain from Key Vault
Tuesday, June 18. 2019
systemd setting overrides
Monday, June 17. 2019
In couple past posts of mine, I've instructed people to do alter systemd service descriptions. Examples from Randomness in computers and Handling /run with systemd. As we all know, systemd is quite a beast. It just keeps on giving complexity as we stumble along trying to grasp all of it.
For example:
To add more command arguments to rngd.service, you can do what I instructed earlier. You can copy /usr/lib/systemd/system/rngd.service to /etc/systemd/system/, edit the file and do a systemctl daemon-reload to update the changes.
If you want to choose more systemd'ic (Python developers always say "pythonic") way, you can do a:
systemctl edit rngd
This command will open a text-editor. The editor is your default one from EDITOR environment variable, or if you haven't picked one, a default will be chosen for you by your favorite Linux distro vendor.
What you should make the text file contain, is following three (3) lines:
[Service]
ExecStart=
ExecStart=/sbin/rngd -f --rng-device=/dev/TrueRNG --fill-watermark=4000
Those lines will re-define service description. First by clearing out the previous value(s) and then defining a new one. On save, this setting will take automatically effect and you don't have to do anything else. Also, this setting is persisted in a file called /etc/systemd/system/rngd.service.d/override.conf. Of course, you can create that particular file yourself, but then the familiar systemctl daemon-reload is needed to make your changes stick.
Nice and easy!
New microphone
Monday, June 10. 2019
It's not that you'd be talking all the time, but quite often a good microphone is needed. It may be (video)conferencing to somebody or just to get your multiplayer game coordinated with the other people you're playing with. Lot of people are happy using the tiny mic in their headphones, but not me. I'd rather invest some real money to a proper piece of hardware to get my sound transmitted over crystal clear.
Since I didn't want to go for ridiculously expensive studio ones, I stayed below 300 € price range and went for a Røde NT-USB (details are at https://www.rode.com/microphones/nt-usb). The microphone would work as a self-standing desk mic, but adding a few options allows me to amp up the experience to a near-studio -quality.
This is what my rig looks like:
As you can see, there is a PSA1 boom arm and a SMR shock mount to keep the sound quality better when I bang the desk in rage.
Mic itself looks like this:
The metal ring used to fasten the microphone to a stand gives you indication of the quality of this product. No messing around here. No flimsy plastic screws. Steel!
Also the acronym USB gives you a hint about how you might connect this lump of metal to a computer, using USB 2.0 interface on the bottom of the microphone. If this would be professional-quality, instead of USB-B connector, you would use for example XLR-connector for cabling. This would leave you to do the analog-to-digital -conversion by yourself. I chose this particular unit for the reason it hooks up to your PC/Mac/Linux/whatever directly. Here no extra stuff needed, but the setup is limited by USB's 5 meter max. cable length. There is plenty of USB-cable in the box, so don't worry about running out.
Shock mount is for reducing any possible noise caused by accidental headbump into desk or microphone. As suggested, the mount absorbs most of the shock and not transmitting really weird noises over. This is how the "cradle" looks like:
There is a windshield reducing any air blowing from me towards the microphone. Again, reducing any weird noises sounding like I was hit by a hurricane to being transmitted over. The shock mount connects to the boom arm using a 5/8" (or 3/8") screw:
As you can see, there is an adapter there allowing you to use pretty much any mic boom of your choice. I chose to go full on with Røde.
Important thing is to note, that manufacturer does NOT recommend using SMR shock-mount with NT-USB microphone. Product details at https://www.rode.com/accessories/smr do NOT list NT-USB as being compatible or related product. The reason is not as dramatical as you might think. The products are compatible, but:
In a scenario, where you would use the USB to transmit sound back to your headphones via 3.5mm jack in the mic, it would be difficult for you to change the headphones volume as the volume knobs aren't that easy to access. You can access them, but not as well as manufacturer would love you to. So, they simply flag the products as "incompatible".
Ultimately, I've been really happy with the product. My sound is heard extremely well on the other side. Helping with this is the boom arm, which lets me place the microphone to almost any location of my choosing while doing my computing, whatever type of computing that might be. The best thing is the very high quality of the product. I don't think I'll be buying a new mic anytime soon.
Vim's comment line leaking fix! Part 3
Wednesday, June 5. 2019
Adding a source of randomness to a Linux
Monday, June 3. 2019
Randomness in computers
You don't need to know much about computers to understand, that computers cannot do random things. Yes, all programming languages and libraries do offer you a rand()-function to emulate randomness. However, the resulting output will follow the carefully crafted programming implementing this "randomness". The most trivial pseudo-random functions will merely provide a sequence of numbers appearing random, but this sequence can be reset to start from beginning making the "randomness" predicatable. That's not really very random, huh!
Improved randomness in computers
To be fair, there does exist improved pseudo-random algorithms which take their initial seed-values from something volatile (time is one such volatile parameter) making the quality of randomness better. Still, even high-quality pseudo-random algorithm is just complex sequence of operations, which will produce duplicate results on same input values. Sometimes its just very tricky to craft a situation where all of the input values would match.
If somebody is capable of doing that, your randomness changes into predictability. Read the story of Dual_EC_DRBG on Wikipedia https://en.wikipedia.org/wiki/Dual_EC_DRBG. When you're generating your precious private keys, you don't want anybody (including NSA) to be able to guess what you have there.
Random source in Linux
Since a proper random source is something every single user, developer and sysadmin would love to have, the problem has been approached on your Linux by authors of the operating system. An excellent description can be found from Wikipedia article https://en.wikipedia.org/wiki//dev/random#Linux. Briefly put, your Linux will collect environmental entropy from number of sources (including human interaction with keyboard and mouse) to a pool, which can then be used to produce naturally random numbers. It actually works very well, the quality of randomness is top-notch.
Obvious problem with this approach is, that you cannot pull too many random numbers out of this source without exhausting it. The fix is to keep typing something while moving your mouse (not a joke!) to generate entropy for the random source. This will eventually help fill the entropy pool and /dev/random will spit couple bytes more.
Those users who have exhausted their /dev/random on an idling rack server without a console keyboard, mouse and video know that it takes painfully long for the entropy pool to fill. A busy server doing something will be able to fill the pool much faster.
A real random source
If you need a real proper random source, which works without human intervention and can provide really good randomness as a stream, there are possibilities on hardware. I know of two good ones, Simtec Electronics Entropy Key and ubld.it TrueRNG Hardware Random Number Generator.
Note: if you consider getting one, get the TrueRNG version 3 (http://ubld.it/truerng_v3). Its just that I have the 1st gen version at hand and haven't found the reason to upgrade.
My TrueRNG looks like this:
It is essentially an USB-stick.
Linux lsusb info essentially identifies it as a Microchip (vendor ID 0x04d8) manufactured USB-device (with ID 0xf5fe) providing RS-232 communications:
Bus 002 Device 009: ID 04d8:f5fe Microchip Technology, Inc.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 2 Communications
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x04d8 Microchip Technology, Inc.
idProduct 0xf5fe
bcdDevice 1.00
iManufacturer 1 ubld.it
iProduct 2 TrueRNG
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0043
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 0
CDC Header:
bcdCDC 1.10
CDC ACM:
bmCapabilities 0x02
line coding and serial state
CDC Union:
bMasterInterface 0
bSlaveInterface 1
CDC Call Management:
bmCapabilities 0x00
bDataInterface 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0001
Self Powered
And by looking at /dev/, there is a /dev/ttyACM0. That's how udevd will populate a CDC-device when it sees one.
How is this a "true" random source?
Oh, that's easy. The device will produce a random 0 or 1 bit constantly when its on. Or to be precise, there is an internal algorithm producing those based on a constant flow of electrons on a transistor PN-surface. The exact phenomenon is called avalance effect or avalance breakdown. For those who can do electronics, there is a good explanation about this in Difference Between Avalanche Breakdown and Zener Breakdown (I borrowed the visualisation pic from above link).
To (over)simplify that, in a carefully constructed electronic circuit, inside a transistor an electron may or may not be emitted on the other side of a semiconducting surface. The occurrence is as random as it can be in nature. Other circuitry will detect this random flow of electrons (or lack of flow) to produce ones and zeros.
What makes this a really good for randomness, as it is well established that this avalance of electrons will happen. Also, it will happen often enough to produce a stream of events. It's just that we don't know exactly WHEN the avalance of electrons will happen. If you time-slice this to slots, a slot can be empty (no avalance) or full (electrons avalanching).
Linux tweaking:
udev
Anybody having multiple devices in their Linuxes knows, that you really cannot control which device name some specific device will get on reboot. To overcome that, udevd can be instructed to do things when it sees a device. My rules for TrueRNG include setting it to highest possible speed and creating a symlink-device so, that I can point to a known source of random. Also, I'm loosening access to that source of randomness to any users belonging to dialout-group. If I wouldn't do that, only root would have access to this fine random-source.
My /etc/udev/rules.d/99-TrueRNG.rules contains:
SUBSYSTEM=="tty", ATTRS{product}=="TrueRNG", SYMLINK+="TrueRNG", RUN+="/bin/stty raw -echo -ixoff -F /dev/%k speed 3000000"
ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="f5fe", ENV{ID_MM_DEVICE_IGNORE}="1", GROUP="dialout", MODE="0664"
If you want to take your random-device for a spin, you can do something like:
dd if=/dev/TrueRNG of=random.bytes bs=64 count=1024
That would create a file of 64 KiB containing very very random bytes. In theory you can just cp data out of the character device, but since it has an infite flow, you'll need to cut it at one point.
rngd
Remember the part I said earlier about Linux using your keypresses and mouse movements as entropy source for randomness. Even with the USB-stick popped into a PC, that still remains the case. What needs to be done next is to offer a helping hand to the Linux kernel and make sure the entropy pool is always full.
My Fedora has package called rng-tools. It is packaged from Mr. Horman's https://github.com/nhorman/rng-tools. What's in there are the tools for pumping those precious truly random bits out of the USB-source to Linux kernel's entropy pool. As default, rngd will use /dev/hwrng as the source for randomness. Some Linuxes don't have that device at all, some Linuxes point that into CPU's random source. What's guaranteed, it will not point to your USB-stick! We need to change that.
Btw. you might be horrified by the fact, that something is fidding with your randomness. The exact bits transferred from USB to entropy pool won't be the actual bits getting out of /dev/random. Your keypresses and many other events are still a factor. Its still a good idea to not run randomness-monitoring malware or spyware in your Linux.
Systemd works so, that I did create a copy of /usr/lib/systemd/system/rngd.service into /etc/systemd/system/rngd.service. The contents of the copy in /etc/systemd/system/ can be freely modified and it has priority over the /usr/lib/systemd/system/ one. The only change I made was to have the ExecStart-line say as:
ExecStart=/sbin/rngd -f --rng-device=/dev/TrueRNG --fill-watermark=4000
When rngd-service would be started, it will use the USB-stick as source and make sure, there are at least 4000 bits of entropy in the pool.
Making sure rngd setup works
At any given point, you can query how many bits are available in the Linux entropy-pool:
cat /proc/sys/kernel/random/entropy_avail
Since my setup is working correctly, it will display a number greater than 4000 and smaller than 4096. The upper limit comes from /proc/sys/kernel/random/poolsize, which is a hard-coded number from Linux kernel source.
Hint: If you do the stupid thing like I did and set the /proc/sys/kernel/random/write_wakeup_threshold (using --fill-watermark) into 4096 (or above), your rngd will keep hogging CPU like there is no tomorrow. It is impossible for the pool to contain maximum number of bits at any given time. Give your system a break and set the threshold bit lower than max.
Finally
It's always nice to know for a fact, that random numbers are random. This fact can be verified and has been verified by number of other people.
Enjoy!
Bacula 9 vchanger: Tape count fix
Sunday, June 2. 2019
One of the first ever blog posts I've written here is about Bacula, the open-source backup software (more at https://www.bacula.org/). I published Fedora 17 binaries for the virtual tape changer running for Bacula 7. The post from year 2013 is here.
Running Bacula in Fedora Linux isn't much of a trick, ready-made binaries are available by the distro and configuring one is covered in Bacula's documentation. Then again, running Bacula with a NAS (see Wikipedia for Network-attached storage) as storage backend is where things get very very tricky. I've written about my Qnap NAS-device's support earlier, see the post about that.
Since its inception, Bacula is baked to require a tape drive (or drives) and a set of tapes (a single tape is supported also). Given modern day computing environment, actual physical tapes aren't used that much. Even I stopped using DLT (Wikipedia Digital Linear Tape) or LTO (Wikipedia Linear Tape-Open) tapes years ago and went for an easy, fast and inexpensive solution for storing my backups on a NAS. So, I really do need to have a concept of a "tape" somehow. That's where the virtual Bacula tape changer steps in. It is a piece of software attaching to Bacula autochanger API emulating a virtual "tape" drive and set of tapes with all the necessary operations, but doing all that on a filesystem. More details about autochangers can be found from Bacula Autochanger Resource page.
The obvious idea is to create a set of files to act as a set of "tapes". For system administration purposes, the tapes are just files in a subdirectory. Smart thing to do is to make that particular subdirectory located on a NAS to store the backups where there is plenty of external capacity outside your system. In my case, I'll access them over an iSCSI-mounted filesystem. More details about iSCSI on a Linux can be found from RedHat Enterprise Linux 7 manual pages at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/online-storage-management#osm-target-setup. For those planning something similar: I chose NOT to go with a NFS. A NFS-connection get stuck very easily and you will be rebooting your stuff a lot. See How-To: Release Stuck NFS Mounts without a Reboot @ Linux Journal for more about that.
When I went to Fedora 29, my Bacula setup got an automatic bump to version 9. My previous setup was for Bacula version 7 and quite soon I realized that I needed to alter my vchanger somehow to get it to support version 9. Bacula-guys did make changes to autochanger-API in their version-bump process. Luckily vchanger author was ahead of me and I got the code from http://sourceforge.net/projects/vchanger/. Soon realized that when I did a simple command of vchanger /etc/qnap.conf LIST, it displayed an extra tape which didn't exist in reality. I was puzzled. Old setup displayed the tape count correctly.
I did some C++ debugging and found out an obvious bug in the code. In src/diskchanger.cpp, DiskChanger-class InitializeVirtSlots()-method calculates the last changer slot numer incorrectly. It is guaranteed to be one-off. After fixing this, I contacted the vchanger author Mr. J. Fisher about my findings, and he agreed, there was a bug in his code.
Unfortunately, couple of months have passed and there is no 1.0.3 release yet, so the fix isn't in the SourceForge git-repo yet. For Fedora-users, my RPMs are available at http://opensource.hqcodeshop.com/Bacula/vchanger for B9/. Go get them there! I've been using those since last December, so I think my fix is correct and doesn't introduce any issues.
Apple iOS device reset - Dismantling an old phone to be sold
Thursday, May 30. 2019
Every one of use will eventually end up in a situation where old mobile device is upgraded to a new one. Most of us can manage getting the new one working without problems. There are backups somewhere in the cloud and the new device will have the intial setup done from the backup and everything in the out-of-the-box experience will go smoothly.
But what about the old one? You might want to sell or give or donate the perfectly functioning piece of hardware to somebody who wants it more. But not without your data, accounts and passwords!
Apple support has this HT201351 article What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch. It instructs you to do a full erase of the device, but doesn't go too much into the details.
Personally, I've struggled with this one a number of times. So, I decided to record the full sequence for me and anybody else needing it. Here goes!
Start with Settings, General. In the bottom of General-menu, there is Reset. That's your choice. For curious ones, you can go see the menus and choices without anything dangerous happening. You WILL get plenty of warning before all your precious data is gone.
In Reset, there are number of levels of reseting to choose from. You want to go all the way. To erase every single bit of your personal data from the device. To get that, go for Erase All Content and Settings.
You will have two separate warnings about your intent to destroy your data. Even if you pass that gateway, there is more. Nothing will be erased until a final blow.
The final thing to do is to inform Apple, that this device won't be associated to your Apple ID anymore. For that, your password will be needed. This is the final call. When you successfully punch in your password, then the big ball starts rolling.
When you see this, you're past point-of-no-return.
It takes a while to erase all data. Wait patiently.
When all the erasing is done, the device will restart and it will go for the out-of-the-box dialog. This is where new user needs to choose the user interface language, network and associate the device with their own Apple ID.
