Tag Archives: debian

OpenPGP smartcard with GNOME on Debian 11 Bullseye

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The Debian operating system is what I have been using on my main computer for what is probably around 20 years. I am now in the process of installing the hopefully soon released Debian 11 “bullseye” on my Lenovo X201 laptop. Getting a OpenPGP smartcard to work has almost always required some additional effort, but it has been reliable enough to use exclusively for my daily GnuPG and SSH operations since 2006. In the early days, the issues with smartcards were not related to GNOME, see my smartcard notes for Debian 4 Etch for example. I believe with Debian 5 Lenny, Debian 6 Squeeze, and Debian 7 Stretch things just worked without workarounds, even with GNOME. Those were the golden days! Back in 2015, with Debian 8 Jessie I noticed a regression and came up with a workaround. The problems in GNOME were not fixed, and I wrote about how to work around this for Debian 9 Stretch and the slightly different workaround needed for Debian 10 Buster. What will Bullseye be like?

The first impression of working with GnuPG and a smartcard is still the same. After inserting the GNUK that holds my private keys into my laptop, nothing happens by default and attempting to access the smartcard results in the following.

jas@latte:~$ gpg --card-status
gpg: error getting version from 'scdaemon': No SmartCard daemon
gpg: OpenPGP card not available: No SmartCard daemon
jas@latte:~$

The solution is to install the scdaemon package. My opinion is that either something should offer to install it when the device is inserted (wasn’t there a framework for discovering hardware and installing the right packages?) or this package should always be installed for a desktop system. Anyway, the following solves the problem.

jas@latte:~$ sudo apt install scdaemon
...
jas@latte:~$ gpg --card-status
 Reader ………..: 234B:0000:FSIJ-1.2.14-67252015:0
 Application ID …: D276000124010200FFFE672520150000
...
 URL of public key : https://josefsson.org/key-20190320.txt
...

Before the private key in the smartcard can be used, the public key must be imported into GnuPG. I now believe the best way to do this (see earlier posts for alternatives) is to configure the smartcard with a public key URL and retrieve it as follows.

jas@latte:~$ gpg --card-edit
 Reader ………..: 234B:0000:FSIJ-1.2.14-67252015:0
...
 gpg/card> fetch
 gpg: requesting key from 'https://josefsson.org/key-20190320.txt'
 gpg: key D73CF638C53C06BE: public key "Simon Josefsson simon@josefsson.org" imported
 gpg: Total number processed: 1
 gpg:               imported: 1
 gpg/card> quit
jas@latte:~$ gpg -K
 /home/jas/.gnupg/pubring.kbx
 sec#  ed25519 2019-03-20 [SC] [expires: 2021-08-21]
       B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
 uid           [ unknown] Simon Josefsson simon@josefsson.org
 ssb>  ed25519 2019-03-20 [A] [expires: 2021-08-21]
 ssb>  ed25519 2019-03-20 [S] [expires: 2021-08-21]
 ssb>  cv25519 2019-03-20 [E] [expires: 2021-08-21]
jas@latte:~$

The next step is to mark your own key as ultimately trusted, use the fingerprint shown above together with gpg --import-ownertrust. Warning! This is not the general way to remove the warning about untrusted keys, this method should only be used for your own keys.

jas@latte:~$ echo "B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE:6:" | gpg --import-ownertrust
gpg: inserting ownertrust of 6
jas@latte:~$ gpg -K
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: next trustdb check due at 2021-08-21
 /home/jas/.gnupg/pubring.kbx
sec#  ed25519 2019-03-20 [SC] [expires: 2021-08-21]
       B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid           [ultimate] Simon Josefsson simon@josefsson.org
ssb>  cv25519 2019-03-20 [E] [expires: 2021-08-21]
ssb>  ed25519 2019-03-20 [A] [expires: 2021-08-21]
ssb>  ed25519 2019-03-20 [S] [expires: 2021-08-21]
jas@latte:~$

Now GnuPG is able to both sign, encrypt, and decrypt data:

jas@latte:~$ echo foo|gpg -a --sign|gpg --verify
 gpg: Signature made Sat May  1 16:02:49 2021 CEST
 gpg:                using EDDSA key A3CC9C870B9D310ABAD4CF2F51722B08FE4745A2
 gpg: Good signature from "Simon Josefsson simon@josefsson.org" [ultimate]
 jas@latte:~$ echo foo|gpg -a --encrypt -r simon@josefsson.org|gpg --decrypt
 gpg: encrypted with 256-bit ECDH key, ID 02923D7EE76EBD60, created 2019-03-20
       "Simon Josefsson simon@josefsson.org"
 foo
jas@latte:~$

To make SSH work with the smartcard, the following is the GNOME-related workaround that is still required. The problem is that the GNOME keyring enables its own incomplete SSH-agent implementation. It is lacking the smartcard support that the GnuPG agent can provide, and even set the SSH_AUTH_SOCK environment variable if the enable-ssh-support parameter is provided.

jas@latte:~$ ssh-add -L
 The agent has no identities.
jas@latte:~$ echo $SSH_AUTH_SOCK 
 /run/user/1000/keyring/ssh
jas@latte:~$ mkdir -p ~/.config/autostart
jas@latte:~$ cp /etc/xdg/autostart/gnome-keyring-ssh.desktop ~/.config/autostart/
jas@latte:~$ echo 'Hidden=true' >> .config/autostart/gnome-keyring-ssh.desktop 
jas@latte:~$ echo enable-ssh-support >> ~/.gnupg/gpg-agent.conf

For some reason, it does not seem sufficient to log out of GNOME and then login again. Most likely some daemon is still running, that has to be restarted. At this point, I reboot my laptop and then log into GNOME again. Finally it looks correct:

jas@latte:~$ echo $SSH_AUTH_SOCK 
 /run/user/1000/gnupg/S.gpg-agent.ssh
jas@latte:~$ ssh-add -L
 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILzCFcHHrKzVSPDDarZPYqn89H5TPaxwcORgRg+4DagE cardno:FFFE67252015
jas@latte:~$

Please discuss in small groups the following topics:

  • How should the scdaemon package be installed more automatically?
  • Should there a simple command to retrieve the public key for a smartcard and set it as ultimately trusted? The two step --card-edit and --import-ownertrust steps is a bad user interface and is not intuitive in my opinion.
  • Why is GNOME keyring used for SSH keys instead of ssh-agent/gpg-agent?
  • Should gpg-agent have enable-ssh-support on by default?

After these years, I would probably feel a bit of sadness if the problems were fixed, since then I wouldn’t be able to rant about this problem and celebrate installing Debian 12 Bookworm the same way I have done for the some past releases.

Thanks for reading and happy hacking!

Passive Icinga Checks: icinga-pusher

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I use Icinga to monitor the availability of my Debian/OpenWRT/etc machines. I have relied on server-side checks on the Icinga system that monitor the externally visible operations of the services that I care about. In theory, monitoring externally visible properties should be good enough. Recently I had one strange incident that was due to an out of disk space on one system. This prompted me to revisit my thinking, and to start monitor internal factors as well. This would allow me to detect problems before they happen, such as an out of disk space condition.

Another reason that I only had server-side checks was that I didn’t like the complexity of the Icinga agent nor wanted to open up for incoming SSH connections from the Icinga server on my other servers. Complexity and machine-based authorization tend to lead to security problems so I prefer to avoid them. The manual mentions agents that use the REST API which was that start of my journey into something better.

What I would prefer is for the hosts to push their self-test results to the central Icinga server. Fortunately, there is a Icinga REST API in modern versions of Icinga (including version 2.10 that I use). The process-check-result API can be used to submit passive check results. Getting this up and running required a bit more research and creativity than I would have hoped for, so I thought it was material enough for a blog post. My main requirement was to keep complexity down, hence I ended up with a simple shell script that is run from cron. None of the existing API clients mentioned in the manual appealed to me.

Prepare the Icinga server with some configuration changes to support the push clients (replace blahonga with a fresh long random password). 

icinga# cat > /etc/icinga2/conf.d/api-users.conf
object ApiUser "pusher" {
  password = "blahonga"
  permissions = [ "actions/process-check-result" ]
}
^D
icinga# icinga2 feature enable api && systemctl reload icinga2

Then add some Service definitions and assign it to some hosts, to /etc/icinga2/conf.d/services.conf: 

apply Service "passive-disk" {
  import "generic-service"
  check_command = "passive"
  check_interval = 2h
  assign where host.vars.os == "Debian"
}
apply Service "passive-apt" {
  import "generic-service"
  check_command = "passive"
  check_interval = 2h
  assign where host.vars.os == "Debian"
 }

I’m using a relaxed check interval of 2 hours because I will submit results from a cron job that is run every hour. The next step is to setup the machines to submit the results. Create a /etc/cron.d/icinga-pusher with the content below. Note that % characters needs to be escaped in crontab files. I’m running this as the munin user which is a non-privileged account that exists on all of my machines, but you may want to modify this. The check_disk command comes from the monitoring-plugins-basic Debian package, which includes other useful plugins like check_apt that I recommend. 

30 * * * * munin /usr/local/bin/icinga-pusher `hostname -f` passive-apt /usr/lib/nagios/plugins/check_apt

40 * * * * munin /usr/local/bin/icinga-pusher `hostname -f` passive-disk "/usr/lib/nagios/plugins/check_disk -w 20\% -c 5\% -X tmpfs -X devtmpfs"

My icinga-pusher script requires a configuration file with some information about the Icinga setup. Put the following content in /etc/default/icinga-pusher (again replacing blahonga with your password): 

ICINGA_PUSHER_CREDS="-u pusher:blahonga"
ICINGA_PUSHER_URL="https://icinga.yoursite.com:5665"
ICINGA_PUSHER_CA="-k"

The parameters above are used by the icinga-pusher script. The ICINGA_PUSHER_CREDS contain the api user credentials, either a simple "-u user:password" combination or it could be "--cert /etc/ssl/yourclient.crt --key /etc/ssl/yourclient.key". The ICINGA_PUSHER_URL is the base URL of your Icinga setup, for the API port which is usually 5665. The ICINGA_PUSHER_CA is "--cacert /etc/ssl/icingaca.crt" or "-k" to not use any CA verification (not recommended!).

Below is the script icinga-pusher itself. Some error handling has been removed for brevity — I have put the script in a separate “icinga-pusher” git repository which will be where I make any updates to this project in the future. 

#!/bin/sh

# Copyright (C) 2019 Simon Josefsson.
# Released under the GPLv3+ license.

. /etc/default/icinga-pusher

HOST="$1"
SERVICE="$2"
CMD="$3"

OUT=$($CMD)
RC=$?

oIFS="$IFS"
IFS='|'
set -- $OUT
IFS="$oIFS"

OUTPUT="$1"
PERFORMANCE="$2"

data='{ "type": "Service", "filter": "host.name==\"'$HOST'\" && service.name==\"'$SERVICE'\"", "exit_status": '$RC', "plugin_output": "'$OUTPUT'", "performance_data": "'$PERFORMANCE'" }'

curl $ICINGA_PUSHER_CA $ICINGA_PUSHER_CREDS \
     -s -H 'Accept: application/json' -X POST \
     "$ICINGA_PUSHER_URL/v1/actions/process-check-result" \
     -d "$data"

exit 0

What do you think? Is there a simpler way of achieving what I want? Thanks for reading.

OpenPGP smartcard under GNOME on Debian 10 Buster

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Debian buster is almost released, and today I celebrate midsummer by installing (a pre-release) of it on my Lenovo X201 laptop. Everything went smooth, except for the usual issues with smartcards under GNOME. I use a FST-01G running Gnuk, but the same issue apply to all OpenPGP cards including YubiKeys. I wrote about this problem for earlier releases, read Smartcards on Debian 9 Stretch and Smartcards on Debian 8 Jessie. Some things have changed – now GnuPG‘s internal ccid support works, and dirmngr is installed by default when you install Debian with GNOME. I thought I’d write a new post for the new release.

After installing Debian and logging into GNOME, I start a terminal and attempt to use the smartcard as follows.

jas@latte:~$ gpg --card-status
gpg: error getting version from 'scdaemon': No SmartCard daemon
gpg: OpenPGP card not available: No SmartCard daemon
jas@latte:~$

The reason is that the scdaemon package is not installed. Install it as follows.

jas@latte:~$ sudo apt-get install scdaemon

After this, gpg --card-status works. It is now using GnuPG’s internal CCID library, which appears to be working. The pcscd package is not required to get things working any more — however installing it also works, and you might need pcscd if you use other applications that talks to the smartcard.

jas@latte:~$ gpg --card-status
Reader ...........: Free Software Initiative of Japan Gnuk (FSIJ-1.2.14-67252015) 00 00
Application ID ...: D276000124010200FFFE672520150000
Version ..........: 2.0
Manufacturer .....: unmanaged S/N range
Serial number ....: 67252015
Name of cardholder: Simon Josefsson
Language prefs ...: sv
Sex ..............: man
URL of public key : https://josefsson.org/key-20190320.txt
Login data .......: jas
Signature PIN ....: inte tvingad
Key attributes ...: ed25519 cv25519 ed25519
Max. PIN lengths .: 127 127 127
PIN retry counter : 3 3 3
Signature counter : 710
KDF setting ......: off
Signature key ....: A3CC 9C87 0B9D 310A BAD4  CF2F 5172 2B08 FE47 45A2
      created ....: 2019-03-20 23:40:49
Encryption key....: A9EC 8F4D 7F1E 50ED 3DEF  49A9 0292 3D7E E76E BD60
      created ....: 2019-03-20 23:40:26
Authentication key: CA7E 3716 4342 DF31 33DF  3497 8026 0EE8 A9B9 2B2B
      created ....: 2019-03-20 23:40:37
General key info..: [none]
jas@latte:~$

As before, using the key does not work right away:

jas@latte:~$ echo foo|gpg -a --sign
gpg: no default secret key: No public key
gpg: signing failed: No public key
jas@latte:~$

This is because GnuPG does not have the public key that correspond to the private key inside the smartcard.

jas@latte:~$ gpg --list-keys
jas@latte:~$ gpg --list-secret-keys
jas@latte:~$

You may retrieve your public key from the clouds as follows. With Debian Buster, the dirmngr package is installed by default so there is no need to install it. Alternatively, if you configured your smartcard with a public key URL that works, you may type “retrieve” into the gpg --card-edit interactive interface. This could be considered slightly more reliable (at least from a self-hosting point of view), because it uses your configured URL for retrieving the public key rather than trusting clouds.

jas@latte:~$ gpg --recv-keys "A3CC 9C87 0B9D 310A BAD4  CF2F 5172 2B08 FE47 45A2"
gpg: key D73CF638C53C06BE: public key "Simon Josefsson <simon@josefsson.org>" imported
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   2  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: next trustdb check due at 2019-10-22
gpg: Total number processed: 1
gpg:               imported: 1
jas@latte:~$

Now signing with the smart card works! Yay! Btw: compare the output size with the output size in the previous post to understand the size advantage with Ed25519 over RSA.

jas@latte:~$ echo foo|gpg -a --sign
-----BEGIN PGP MESSAGE-----

owGbwMvMwCEWWKTN8c/ddRHjaa4khlieP//S8vO5OkpZGMQ4GGTFFFkWn5nTzj3X
kGvXlfP6MLWsTCCFDFycAjARscUM/5MnXTF9aSG4ScVa3sDiB2//nPSVz13Mkpbo
nlzSezowRZrhn+Ky7/O6M7XljzzJvtJhfPvOyS+rpyqJlD+buumL+/eOPywA
=+WN7
-----END PGP MESSAGE-----

As before, encrypting to myself does not work smoothly because of the trust setting on the public key. Witness the problem here:

jas@latte:~$ echo foo|gpg -a --encrypt -r simon@josefsson.org
gpg: 02923D7EE76EBD60: There is no assurance this key belongs to the named user

sub  cv25519/02923D7EE76EBD60 2019-03-20 Simon Josefsson <simon@josefsson.org>
 Primary key fingerprint: B1D2 BD13 75BE CB78 4CF4  F8C4 D73C F638 C53C 06BE
      Subkey fingerprint: A9EC 8F4D 7F1E 50ED 3DEF  49A9 0292 3D7E E76E BD60

It is NOT certain that the key belongs to the person named
in the user ID.  If you *really* know what you are doing,
you may answer the next question with yes.

Use this key anyway? (y/N) 
gpg: signal Interrupt caught ... exiting

jas@latte:~$

You update the trust setting with the gpg --edit-key command. Take note that this is not the general way of getting rid of the “There is no assurance this key belongs to the named user” warning — using a ultimate trust setting is normally only relevant for your own keys, which is the case here.

jas@latte:~$ gpg --edit-key simon@josefsson.org
gpg (GnuPG) 2.2.12; Copyright (C) 2018 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Secret subkeys are available.

pub  ed25519/D73CF638C53C06BE
     created: 2019-03-20  expires: 2019-10-22  usage: SC  
     trust: unknown       validity: unknown
ssb  cv25519/02923D7EE76EBD60
     created: 2019-03-20  expires: 2019-10-22  usage: E   
     card-no: FFFE 67252015
ssb  ed25519/80260EE8A9B92B2B
     created: 2019-03-20  expires: 2019-10-22  usage: A   
     card-no: FFFE 67252015
ssb  ed25519/51722B08FE4745A2
     created: 2019-03-20  expires: 2019-10-22  usage: S   
     card-no: FFFE 67252015
[ unknown] (1). Simon Josefsson <simon@josefsson.org>

gpg> trust
pub  ed25519/D73CF638C53C06BE
     created: 2019-03-20  expires: 2019-10-22  usage: SC  
     trust: unknown       validity: unknown
ssb  cv25519/02923D7EE76EBD60
     created: 2019-03-20  expires: 2019-10-22  usage: E   
     card-no: FFFE 67252015
ssb  ed25519/80260EE8A9B92B2B
     created: 2019-03-20  expires: 2019-10-22  usage: A   
     card-no: FFFE 67252015
ssb  ed25519/51722B08FE4745A2
     created: 2019-03-20  expires: 2019-10-22  usage: S   
     card-no: FFFE 67252015
[ unknown] (1). Simon Josefsson <simon@josefsson.org>

Please decide how far you trust this user to correctly verify other users' keys
(by looking at passports, checking fingerprints from different sources, etc.)

  1 = I don't know or won't say
  2 = I do NOT trust
  3 = I trust marginally
  4 = I trust fully
  5 = I trust ultimately
  m = back to the main menu

Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y

pub  ed25519/D73CF638C53C06BE
     created: 2019-03-20  expires: 2019-10-22  usage: SC  
     trust: ultimate      validity: unknown
ssb  cv25519/02923D7EE76EBD60
     created: 2019-03-20  expires: 2019-10-22  usage: E   
     card-no: FFFE 67252015
ssb  ed25519/80260EE8A9B92B2B
     created: 2019-03-20  expires: 2019-10-22  usage: A   
     card-no: FFFE 67252015
ssb  ed25519/51722B08FE4745A2
     created: 2019-03-20  expires: 2019-10-22  usage: S   
     card-no: FFFE 67252015
[ unknown] (1). Simon Josefsson <simon@josefsson.org>
Please note that the shown key validity is not necessarily correct
unless you restart the program.

gpg> quit
jas@latte:~$

Confirm gpg --list-keys indicate that the key is now trusted, and encrypting to yourself should work.

jas@latte:~$ gpg --list-keys
/home/jas/.gnupg/pubring.kbx
----------------------------
pub   ed25519 2019-03-20 [SC] [expires: 2019-10-22]
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid           [ultimate] Simon Josefsson <simon@josefsson.org>
sub   ed25519 2019-03-20 [A] [expires: 2019-10-22]
sub   ed25519 2019-03-20 [S] [expires: 2019-10-22]
sub   cv25519 2019-03-20 [E] [expires: 2019-10-22]

jas@latte:~$ gpg --list-secret-keys
/home/jas/.gnupg/pubring.kbx
----------------------------
sec#  ed25519 2019-03-20 [SC] [expires: 2019-10-22]
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid           [ultimate] Simon Josefsson <simon@josefsson.org>
ssb>  ed25519 2019-03-20 [A] [expires: 2019-10-22]
ssb>  ed25519 2019-03-20 [S] [expires: 2019-10-22]
ssb>  cv25519 2019-03-20 [E] [expires: 2019-10-22]

jas@latte:~$ echo foo|gpg -a --encrypt -r simon@josefsson.org
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: next trustdb check due at 2019-10-22
-----BEGIN PGP MESSAGE-----

hF4DApI9fuduvWASAQdA4FIwM27EFqNK1I5eZERaZVDAXJDmYLZQHjZD8TexT3gw
7SDaeTLm7s0QSyKtsRugRpex6eSVhfA3WG8fUOyzbNv4o7AC/TQdhZ2TDtXZGFtY
0j8BRYIjVDbYOIp1NM3kHnMGHWEJRsTbtLCitMWmLdp4C98DE/uVkwjw98xEJauR
/9ZNmmvzuWpaHuEJNiFjORA=
=tAXh
-----END PGP MESSAGE-----
jas@latte:~$

The issue with OpenSSH and GNOME Keyring still exists as in previous releases.

jas@latte:~$ ssh-add -L
The agent has no identities.
jas@latte:~$ echo $SSH_AUTH_SOCK 
/run/user/1000/keyring/ssh
jas@latte:~$

The trick we used last time still works, and as far as I can tell, it is still the only recommended method to disable the gnome-keyring ssh component. Notice how we also configure GnuPG’s gpg-agent to enable SSH daemon support.

jas@latte:~$ mkdir ~/.config/autostart
jas@latte:~$ cp /etc/xdg/autostart/gnome-keyring-ssh.desktop ~/.config/autostart/
jas@latte:~$ echo 'Hidden=true' >> ~/.config/autostart/gnome-keyring-ssh.desktop 
jas@latte:~$ echo enable-ssh-support >> ~/.gnupg/gpg-agent.conf

Log out of GNOME and log in again. Now the environment variable points to gpg-agent’s socket, and SSH authentication using the smartcard works.

jas@latte:~$ echo $SSH_AUTH_SOCK 
/run/user/1000/gnupg/S.gpg-agent.ssh
jas@latte:~$ ssh-add -L
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILzCFcHHrKzVSPDDarZPYqn89H5TPaxwcORgRg+4DagE cardno:FFFE67252015
jas@latte:~$

Topics for further discussion and research this time around includes:

  1. Should scdaemon (and possibly pcscd) be pre-installed on Debian desktop systems?
  2. Could gpg --card-status attempt to import the public key and secret key stub automatically? Alternatively, some new command that automate the bootstrapping of a new smartcard.
  3. Should GNOME keyring support smartcards?
  4. Why is GNOME keyring used by default for SSH rather than gpg-agent?
  5. Should gpg-agent default to enable the SSH daemon?
  6. What could be done to automatically infer the trust setting for a smartcard based private key?

Thanks for reading and happy smartcarding!

Offline Ed25519 OpenPGP key with subkeys on FST-01G running Gnuk

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Below I describe how to generate an OpenPGP key and import its subkeys to a FST-01G device running Gnuk. See my earlier post on planning for my new OpenPGP key and the post on preparing the FST-01G to run Gnuk. For comparison with a RSA/YubiKey based approach, you can read about my setup from 2014.

Most of the steps below are covered by the Gnuk manual. The primary complication for me is the use of a offline machine and storing GnuPG directory stored on a USB memory device.

Offline machine

I use a laptop that is not connected to the Internet and boot it from a read-only USB memory stick. Finding a live CD that contains the necessary tools for using GnuPG with smartcards (gpg-agent, scdaemon, pcscd) is significantly harder than it should be. Using a rarely audited image begs the question of whether you can trust it. A patched kernel/gpg to generate poor randomness would be an easy and hard to notice hack. I’m using the PGP/PKI Clean Room Live CD. Recommendations on more widely used and audited alternatives would be appreciated. Select “Advanced Options” and “Run Shell” to escape the menus. Insert a new USB memory device, and prepare it as follows: 

pgp@pgplive:/home/pgp$ sudo wipefs -a /dev/sdX
pgp@pgplive:/home/pgp$ sudo fdisk /dev/sdX
# create a primary partition of Linux type
pgp@pgplive:/home/pgp$ sudo mkfs.ext4 /dev/sdX1
pgp@pgplive:/home/pgp$ sudo mount /dev/sdX1 /mnt
pgp@pgplive:/home/pgp$ sudo mkdir /mnt/gnupghome
pgp@pgplive:/home/pgp$ sudo chown pgp.pgp /mnt/gnupghome
pgp@pgplive:/home/pgp$ sudo chmod go-rwx /mnt/gnupghome

GnuPG configuration

Set your GnuPG home directory to point to the gnupghome directory on the USB memory device. You will need to do this in every terminal windows you open that you want to use GnuPG in. 

pgp@pgplive:/home/pgp$ export GNUPGHOME=/mnt/gnupghome
pgp@pgplive:/home/pgp$

At this point, you should be able to run gpg --card-status and get output from the smartcard.

Create master key

Create a master key and make a backup copy of the GnuPG home directory with it, together with an export ASCII version. 

pgp@pgplive:/home/pgp$ gpg --quick-gen-key "Simon Josefsson <simon@josefsson.org>" ed25519 sign 216d
gpg: keybox '/mnt/gnupghome/pubring.kbx' created
gpg: /mnt/gnupghome/trustdb.gpg: trustdb created
gpg: key D73CF638C53C06BE marked as ultimately trusted
gpg: directory '/mnt/gnupghome/openpgp-revocs.d' created
gpg: revocation certificate stored as '/mnt/gnupghome/openpgp-revocs.d/B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE.rev'
pub   ed25519 2019-03-20 [SC] [expires: 2019-10-22]
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid                      Simon Josefsson <simon@josefsson.org>

pgp@pgplive:/home/pgp$ gpg -a --export-secret-keys B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/masterkey.txt
pgp@pgplive:/home/pgp$ sudo cp -a $GNUPGHOME $GNUPGHOME-backup-masterkey
pgp@pgplive:/home/pgp$

Create subkeys

Create subkeys and make a backup of them too, as follows.

pgp@pgplive:/home/pgp$ gpg --quick-add-key B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE cv25519 encr 216d
pgp@pgplive:/home/pgp$ gpg --quick-add-key B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE ed25519 auth 216d
pgp@pgplive:/home/pgp$ gpg --quick-add-key B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE ed25519 sign 216d
pgp@pgplive:/home/pgp$ gpg -a --export-secret-keys B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/mastersubkeys.txt
pgp@pgplive:/home/pgp$ gpg -a --export-secret-subkeys B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/subkeys.txt
pgp@pgplive:/home/pgp$ sudo cp -a $GNUPGHOME $GNUPGHOME-backup-mastersubkeys
pgp@pgplive:/home/pgp$

Move keys to card

Prepare the card by setting Admin PIN, PIN, your full name, sex, login account, and key URL as you prefer, following the Gnuk manual on card personalization.

Move the subkeys from your GnuPG keyring to the FST01G using the keytocard command.

Take a final backup — because moving the subkeys to the card modifes the local GnuPG keyring — and create a ASCII armored version of the public key, to be transferred to your daily machine. 

pgp@pgplive:/home/pgp$ gpg --list-secret-keys
/mnt/gnupghome/pubring.kbx
--------------------------
sec   ed25519 2019-03-20 [SC] [expires: 2019-10-22]
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid           [ultimate] Simon Josefsson <simon@josefsson.org>
ssb>  cv25519 2019-03-20 [E] [expires: 2019-10-22]
ssb>  ed25519 2019-03-20 [A] [expires: 2019-10-22]
ssb>  ed25519 2019-03-20 [S] [expires: 2019-10-22]

pgp@pgplive:/home/pgp$ gpg -a --export-secret-keys B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/masterstubs.txt
pgp@pgplive:/home/pgp$ gpg -a --export-secret-subkeys B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/subkeysstubs.txt
pgp@pgplive:/home/pgp$ gpg -a --export B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE > $GNUPGHOME/publickey.txt
pgp@pgplive:/home/pgp$ cp -a $GNUPGHOME $GNUPGHOME-backup-masterstubs
pgp@pgplive:/home/pgp$

Transfer to daily machine

Copy publickey.txt to your day-to-day laptop and import it and create stubs using --card-status. 

jas@latte:~$ gpg --import < publickey.txt 
gpg: key D73CF638C53C06BE: public key "Simon Josefsson <simon@josefsson.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1
jas@latte:~$ gpg --card-status

Reader ...........: Free Software Initiative of Japan Gnuk (FSIJ-1.2.14-67252015) 00 00
Application ID ...: D276000124010200FFFE672520150000
Version ..........: 2.0
Manufacturer .....: unmanaged S/N range
Serial number ....: 67252015
Name of cardholder: Simon Josefsson
Language prefs ...: sv
Sex ..............: male
URL of public key : https://josefsson.org/key-20190320.txt
Login data .......: jas
Signature PIN ....: not forced
Key attributes ...: ed25519 cv25519 ed25519
Max. PIN lengths .: 127 127 127
PIN retry counter : 3 3 3
Signature counter : 0
Signature key ....: A3CC 9C87 0B9D 310A BAD4  CF2F 5172 2B08 FE47 45A2
      created ....: 2019-03-20 23:40:49
Encryption key....: A9EC 8F4D 7F1E 50ED 3DEF  49A9 0292 3D7E E76E BD60
      created ....: 2019-03-20 23:40:26
Authentication key: CA7E 3716 4342 DF31 33DF  3497 8026 0EE8 A9B9 2B2B
      created ....: 2019-03-20 23:40:37
General key info..: sub  ed25519/51722B08FE4745A2 2019-03-20 Simon Josefsson <simon@josefsson.org>
sec   ed25519/D73CF638C53C06BE  created: 2019-03-20  expires: 2019-10-22
ssb>  cv25519/02923D7EE76EBD60  created: 2019-03-20  expires: 2019-10-22
                                card-no: FFFE 67252015
ssb>  ed25519/80260EE8A9B92B2B  created: 2019-03-20  expires: 2019-10-22
                                card-no: FFFE 67252015
ssb>  ed25519/51722B08FE4745A2  created: 2019-03-20  expires: 2019-10-22
                                card-no: FFFE 67252015
jas@latte:~$

Before the key can be used after the import, you must update the trust database for the secret key.

Now you should have a offline master key with subkey stubs. Note in the output below that the master key is not available (sec#) and the subkeys are stubs for smartcard keys (ssb>). 

jas@latte:~$ gpg --list-secret-keys
sec#  ed25519 2019-03-20 [SC] [expires: 2019-10-22]
      B1D2BD1375BECB784CF4F8C4D73CF638C53C06BE
uid           [ultimate] Simon Josefsson <simon@josefsson.org>
ssb>  cv25519 2019-03-20 [E] [expires: 2019-10-22]
ssb>  ed25519 2019-03-20 [A] [expires: 2019-10-22]
ssb>  ed25519 2019-03-20 [S] [expires: 2019-10-22]

jas@latte:~$

If your environment variables are setup correctly, SSH should find the authentication key automatically. 

jas@latte:~$ ssh-add -L
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILzCFcHHrKzVSPDDarZPYqn89H5TPaxwcORgRg+4DagE cardno:FFFE67252015
jas@latte:~$

GnuPG and SSH are now ready to be used with the new key. Thanks for reading!

Vikings D16 server first impressions

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I have bought a 1U server to use as a virtualization platform to host my personal online services (mail, web, DNS, nextCloud, Icinga, Munin etc). This is the first time I have used a high-end libre hardware device that has been certified with the Respects Your Freedom certification, by the Free Software Foundation. To inspire others to buy a similar machine, I have written about my experience with the machine.

The machine I bought has a ASUS KGPE D16 mainboard with modified (liberated) BIOS. I bought it from Vikings.net. Ordering the server was uneventful. I ordered it with two AMD 6278 processors (the Wikipedia AMD Opteron page contains useful CPU information), 128GB of ECC RAM, and a PIKE 2008/IMR RAID controller to improve SATA speed (to be verified). I intend to use it with two 1TB Samsung 850 SSDs and two 5TB Seagate ST5000, configured in RAID1 mode. I was worried that the SATA controller(s) would not be able handle >2TB devices, which is something I have had bad experiences with older Dell RAID controllers before. The manufacturer wasn’t able to confirm that they would work, but I took the risk and went ahead with the order anyway.

One of the order configuration choices was which BIOS to use. I chose their recommended “Petitboot & Coreboot (de-blobbed)” option. The other choices were “Coreboot (de-blobbed)” and “Libreboot”. I am still learning about the BIOS alternatives, and my goal is to compare the various alternatives and eventually compile my own preferred choice. The choice of BIOS still leaves me with a desire to understand more. Petitboot appears more advanced, and has an embedded real Linux kernel and small rescue system on it (hence it requires a larger 16MB BIOS chip). Coreboot is a well known project, but it appears it does not have a strict FOSS policy so there is non-free code in it. Libreboot is a de-blobbed coreboot, and appears to fit the bill for me, but it does not appear to have a large community around it and might not be as updated as coreboot.

The PIKE2008 controll card did not fit with the 1U case that Vikings.net had found for me, so someone on their side must have had a nice day of hardware hacking. The cooler for one chip had a dent in it, which could imply damage to the chip or mainboard. The chip is close to the RAID controller where they modified the 1U case, so I was worried that some physical force had been applied there.

First impressions of using the machine for a couple of days:

  • The graphical installation of Debian 9.x stretch does not start. There is a X11 stack backtrace on booting the ISO netinst image, and I don’t know how to turn the installer into text mode from within the Petitboot boot menu.
  • Petitboot does not appear to detect a bootable system inside a RAID partition, which I have reported. I am now using a raw ext4 /boot partition on one of the SSDs to boot.
  • Debian 8.x jessie installs fine, since it uses text-mode. See my jessie installation report.
  • The graphical part of GRUB in debian 8.x makes graphics not work anymore, so I can’t see the GRUB screen or interact with the booted Debian installation.
  • Reboot time is around 2 minutes and 20 seconds between rsyslogd shuts down and until it starts again.
  • On every other boot (it is fairly stable at 50%) I get the following kernel log message every other second. The 00:14.0 device is the SBx00 SMBus Controller according to lspci, but what this means is a mystery to me. 
    AMD-Vi: Event logged [IO_PAGE_FAULT device=00:14.0 domain=0x000a address=0x000000fdf9103300 flags=0x0030]

That’s it for now! My goal is to get Debian 9.x stretch installed on the machine and perform some heavy duty load testing of the machine before putting it into production. Expect an update if I discover something interesting!