Kushal Das

FOSS and life. Kushal Das talks here.

2017 blog review

Around December 2016, I decided to work more on my writings. After asking around a few friends, and also after reading the suggestions from the masters, it boiled down to one thing. One has to write more. This is no shortcut.

So, I tried to do that through out 2017. I found early morning was the easiest time for me to read/write as there is not much noise, and most importantly, Py still sleeps :).

The biggest point while starting was about what to write? I tried to write about whatever I found useful to me, or things I am excited about. I wrote using FocusWriter (most of the time), and saved the documents as a plain text file (as I use Markdown format in my blog). I also received help from many of my friends, who were kind enough to review my writings. Having a second pair of eyes for the writings is really important, as they can help to not only find the errors, but also show you better ways to express yourself.

One of my weak point (from the childhood) is a small stock of words to express myself. But, that also means my sentences do not have any words which one has to search to find the meaning.

If I just look at the numbers, I wrote 60 blog posts in 2017, which is only 7 more than of 2016. But, the number of views of the HTML pages is more than doubled.

Did your writing skill improved a lot?

The answer is no. But, now, writing is much more easier than ever. I can sit down with any of my mechanical keyboards, and just typing out the things on my mind.

If you ask me about one single thing to read on this topic, I will suggest On Writing by Stephen King.

One thing still can not do on time is replying to emails. Kind of drowned in too many emails. I am trying to slowly unsubscribe from various lists I have joined over the years. I hope you will find the future blog posts useful in different ways.

Duplicate MAC address error in Qubes VMs

Just after I did the fresh install of Qubes 4.0rc3, I saw one error about sys-net (and sometimes same for other VMs) having a duplicate mac address for NIC. I rebooted the system for a few times, which solved the issue.

Start failed: invalid argument: network device with mac 00:16:3e:5e:6c:00 already exists

But, from the last week I started getting the same error again and again. Even if I use the qvm-prefs command to change the mac address, it is still trying to boot using the old address, I could not find the reason behind it. Rebooted the laptop way too many times with a hope of the error vanishing away, but of no use.

At first I checked the file /var/lib/qubes/qubes.xml for the duplicate record of the MAC address, but I found the right value there (the new one I set using the qvm-prefs command).

So, the next step was to remove the whole sys-net. As I forgot that I can not remove it till I remove all the dependency, my qvm-remove sys-net command will fail. I had to remove all dependencies using the Qubes Global Settings. Next, I removed and recreated the vm/domain and created a new one.

$ qvm-remove sys-net
$ sudo su -
# cd /srv/formulas/base/virtual-machines-formula/
# qubesctl top.enable qvm.sys-net
# qubesctl --targets sys-net state.highstate

I am yet to learn about Salt, I found a nice starting guide in the official Qubes documentation.

Share files securely using OnionShare

Sharing files securely is always a open discussion topic. Somehow the relationship between security/privacy and usability stand in the opposite sides. But, OnionShare managed to create a bridge between them. It is a tool written by Micah Lee which helps to share files of any size securely and anonymously using Tor.

In the rest of the post I will talk about how you can this tool in your daily life.

How to install OnionShare?

OnionShare is a Python application and already packaged for most of the Linux distributions. If you are using Windows or Mac OS X, then visit the homepage of the application, and you can find the download links there.

On Fedora, you can just install it using dnf command.

sudo dnf install onionshare -y

For Ubuntu, use the ppa repository from Micah.

sudo add-apt-repository ppa:micahflee/ppa
sudo apt-get update
sudo apt-get install onionshare

How to use the tool?

When you start the tool, it will first try to connect to the Tor network. After a successful connection, it will have a window open where you can select a number of files, and then click on Start sharing button. The tool will take some time to create a random onion URL, which you can then pass to the person who is going to download the files using the Tor Browser.

You can mark any download to stop after the first download (using the settings menu). Because the tool is using Tor, it can punch through standard NAT. Means you can share files from directly your laptop or home desktop. One can still access the files using the Tor Browser.

Because of the nature of Tor, the whole connection is end to end encrypted. This also makes the sharer and downloader anonymous, but you have to make sure that you are sharing the download URL in a secure way (for example, you can share it using Signal). OnionShare also has a rate-limit so that an attacker can not do many attempts to guess the full download URL.

Qubes OS 4.0rc3 and latest UEFI systems

Last week I received a new laptop, I am going to use it as my primary work station. The first step was to install Qubes OS 4.0rc3 on the system. It is a Thinkpad T470 with 32GB RAM and a SSD drive.

How to install Qubes on the latest UEFI systems?

A few weeks back, a patch was merged to the official Qubes documentation, which explains in clear steps how to create a bootable USB drive on a Fedora system using livecd-tools. Please follow the guide and create a USB drive which will work on these latest machines. Just simply using dd will not help.

First step after installing Qubes

I upgraded the dom0 to the current testing packages using the following command.

$ sudo qubes-dom0-update --enablerepo=qubes-dom0-current-testing
$ sudo qubes-dom0-update qubes-template-fedora-26

I also installed the Fedora 26 template on my system using the next command. One of the important point to remember that Fedora 25 is going to be end of life today. So, better to use updated version of the distribution :)

There was another important thing happened in the last two weeks. I was in the Freedom of the Press Foundation office in San Fransisco. Means not only I managed to meet my amazing team, I also met many of my personal heroes in this trip. I may write a separate blog post about that later. But for now I can say that I managed to sit near to Micah Lee for 2 weeks and learn a ton about various things, including his Qubes workflow. The following two things were the first change I did to my installation (with his guidance) to make things working properly.

How to modify the copy-paste between domains shortcuts?

Generally Ctrl+Shift+c and Ctrl+Shift+v are used to copy-paste securely between different domains. But, those are the shortcuts to copy-paste from the terminal in all the systems. So, modifying them to a different key combination is very helpful for the muscle memory :)

Modify the following lines in the /etc/qubes/guid.conf file in dom0, I did a reboot after that to make sure that I am using this new key combination.

secure_copy_sequence = “Mod-c”;
secure_paste_sequence = “Mod-v”;

The above configuration will modify the copy paste shortcuts to Windows+c and Windows+v in my keyboard layout.

Fixing the wireless driver issue in suspend/resume

I also found that if I suspend the system, after starting it on again, the wireless device was missing from the sys-net domain. Adding the following two module in the /rw/config/suspend-module-blacklist file on the sys-net domain helped me to fix that.

iwlmvm
iwlwifi

The official documentation has a section on the same.

You can follow my posts on Qubes OS here.

Setting up SecureDrop 0.5rc2 in VMs for QA

Next week we have the 0.5 release of SecureDrop. SecureDrop is an open-source whistleblower submission system that media organizations can use to securely accept documents from and communicate with anonymous sources. It was originally created by the late Aaron Swartz and is currently managed by Freedom of the Press Foundation.

In this blog post I am going to tell you how can you set up a production instance of SecureDrop in VM(s) in your computer, and help us to test the system for the new release.

Required software

We provision our VM(s) using Vagrant. You will also need access to a GPG key (along with the private key) to test the whole workflow. The set up is done using Ansible playbooks.

Another important piece is a Tails VM for the administrator/journalist workstation. Download the latest (Tails 3.3) ISO from their website.

You will need at least 8GB RAM in your system so that you can have the 3 VM(s) required to test the full system.

Get the source code

For our test, we will first set up a SecureDrop 0.4.4 production system, and then we will update that to the 0.5rc release.

Clone the SecureDrop repository in a directory in your local computer. And then use the following commands to set up two VM(s). One of the VM is for the application server, and the other VM is the monitor server.

$ vagrant up /prod/ --no-provision

In case you don’t have the right image file for KVM, you can convert the Virtualbox image following this blog post.

Create a Tails VM

Follow this guide to create a virtualized Tails environment.

After the boot, remember to create a Persistence storage, and also setup a administrator password (you will have to provide the administrator password everytime you boot the Tails VM).

For KVM, remember to mark the drive as a removable USB storage and also mark it in the Booting Options section after the installation.

Then, you can mount the SecureDrop git repository inside the Tails VM, I used this guide for the same.

Also remember to change the Virtual Network Interface in the virt-manager to Virtual network ‘securedrop0’: NAT for the Tails VM.

Install SecureDrop 0.4.4 release in the production VM(s).

For the next part of the tutorial, I am assuming that the source code is at the ~/Persistent/securedrop directory.

Move to 0.4.4 tag

$ git checkout 0.4.4

We will also have remove a validation role from the 0.4.4 Ansible playbook, otherwise it will fail on a Tails 3.3 system.

diff --git a/install_files/ansible-base/securedrop-prod.yml b/install_files/ansible-base/securedrop-prod.yml
index 877782ff..37b27c14 100755
--- a/install_files/ansible-base/securedrop-prod.yml
+++ b/install_files/ansible-base/securedrop-prod.yml
@@ -11,8 +11,6 @@
# Don't clobber new vars file with old, just create it.
args:
creates: "{{ playbook_dir }}/group_vars/all/site-specific"
- roles:
- - { role: validate, tags: validate }
- name: Add FPF apt repository and install base packages.
hosts: securedrop

Create the configuration

In the host system make sure that you export your GPG public key to a file in the SecureDrop source directory, for my example I stored it in install_files/ansible-base/kushal.pub. I also have the exported insecure key from Vagrant. You can find that key at ~/.vagrant.d/insecure_private_key in your host system. Make sure to copy that file too in the SecureDrop source directory so that we can later access it from the Tails VM.

Inside of the Tails VM, give the following command to setup the dependencies.

$ ./securedrop-admin setup

Next, we will use the sdconfig command to create the configuration file.

$ ./securedrop-admin sdconfig

The above command will ask you many details, you can use the defaults in most cases. I am pasting my configuration file below, so that you can look at the example values I am using. The IP addresses are the default address for the production Vagrant VM(s). You should keep them the same as mine.

---
### Used by the common role ###
ssh_users: vagrant
dns_server: 8.8.8.8
daily_reboot_time: 4 # An integer between 0 and 23

# TODO Should use ansible to gather this info
monitor_ip: 10.0.1.5
monitor_hostname: mon
app_hostname: app
app_ip: 10.0.1.4

### Used by the app role ###
# The securedrop_header_image has to be in the install_files/ansible-base/ or
# the install_files/ansible-base/roles/app/files/ directory
# Leave set to empty to use the SecureDrop logo.
securedrop_header_image: ""
# The app GPG public key has to be in the install_files/ansible-base/ or
# install_files/ansible-base/roles/app/files/ directory
#
# The format of the app GPG public key can be binary or ASCII-armored,
# the extension also doesn't matter
#
# The format of the app gpg fingerprint needs to be all capital letters
# and zero spaces, e.g. "B89A29DB2128160B8E4B1B4CBADDE0C7FC9F6818"
securedrop_app_gpg_public_key: kushal.pub
securedrop_app_gpg_fingerprint: A85FF376759C994A8A1168D8D8219C8C43F6C5E1

### Used by the mon role ###
# The OSSEC alert GPG public key has to be in the install_files/ansible-base/ or
# install_files/ansible-base/roles/app/files/ directory
#
# The format of the OSSEC alert GPG public key can be binary or
# ASCII-armored, the extension also doesn't matter
#
# The format of the OSSEC alert GPG fingerprint needs to be all capital letters
# and zero spaces, e.g. "B89A29DB2128160B8E4B1B4CBADDE0C7FC9F6818"
ossec_alert_gpg_public_key: kushal.pub
ossec_gpg_fpr: A85FF376759C994A8A1168D8D8219C8C43F6C5E1
ossec_alert_email: kushaldas@gmail.com
smtp_relay: smtp.gmail.com
smtp_relay_port: 587
sasl_username: fakeuser
sasl_domain: gmail.com
sasl_password: fakepassword

### Use for backup restores ###
# If the `restore_file` variable is defined, Ansible will overwrite the state of
# the app server with the state from the restore file, which should have been
# created by a previous invocation of the "backup" role.
# To use uncomment the following line and enter the filename between the quotes.
# e.g. restore_file: "sd-backup-2015-01-15--21-03-32.tar.gz"
#restore_file: ""
securedrop_app_https_on_source_interface: False
securedrop_supported_locales: []

Starting the actual installation

Use the following two commands to start the installation.

$ ssh-add insecure_private_key
$ ./securedrop-admin install

Then wait for a while for the installation to finish.

Configure the Tails VM as a admin workstation

$ ./securedrop-admin tailsconfig

The above command expects that the previous installation step finished without any issue. The addresses for the source and journalist interfaces can be found in the install_files/ansible-base/*ths files at this moment.

After this command, you should see two desktop shortcuts on your Tails desktop, one pointing to the source interface, and one for journalist interface. Double click on the source interface and make sure that you can view the source interface and the SecureDrop version mentioned in the page is 0.4.4.

Now update the systems to the latest SecureDrop rc release

The following commands in the Tails VM will help you to update to the latest RC release.

$ source .venv/bin/activate
$ cd install_files/ansible-base
$ torify wget https://gist.githubusercontent.com/conorsch/e7556624df59b2a0f8b81f7c0c4f9b7d/raw/86535a6a254e4bd72022865612d753042711e260/securedrop-qa.yml`
$ ansible-playbook -vv --diff securedrop-qa.yml

Then we will SSH into both app and mon VM(s), and give the following the command to update to the latest RC.

$ sudo cron-apt -i -s

Note: You can use ssh app and ssh mon to connect to the systems. You can also checkout the release/0.5 branch and rerun the tailsconfig command. That will make sure the desktop shortcuts are trusted by default.

After you update both the systems, if you reopen the source interface in the Tails VM again, you should see version mentioned as a RC release.

Now, if you open up the source interface onion address in the Tor browser on your computer, you should be able to submit documents/messages.

SecureDrop hackathon at EFF office next week

On December 7th from 6PM we are having a SecureDrop hackathon at the EFF office. Please RSVP and come over to start contributing to SecureDrop.

PyConf Hyderabad 2017

In the beginning of October, I attended a new PyCon in India, PyConf Hyderabad (no worries, they are working on the name for the next year). I was super excited about this conference, the main reason is being able to meet more Python developers from India. We are a large country, and we certainly need more local conferences :)

We reached the conference hotel a day before the event starts along with Py. The first day of the conference was workshop day, we reached the venue on time to say hi to everyone. Meet the team at the conference and many old friends. It was good to see that folks traveled from all across the country to volunteer for the conference. Of course, we had a certain number of dgplug folks there :)

In the conference day, Anwesha and /my setup in the PSF booth, and talked to the attendees. During the lighting talk session, Sayan and Anwesha introduced PyCon Pune, and they also opened up the registration during the lighting talk :). I attended Chandan Kumar’s talk about his journey into upstream projects. Have to admit that I feel proud to see all the work he has done.

Btw, I forgot to mention that lunch at PyConf Hyderabad was the best conference food ever. They had some amazing biryani :).

The last talk of the day was my keynote titled Free Software movement & current days. Anwesha and I wrote an article on the history of Free Software a few months back, and that the talk was based on that. This was also the first time I spoke about Freedom of the Press Foundation (attended my first conference as the FPF staff member).

The team behind the conference did some amazing groundwork to make this conference happening. It was a good opportunity to meet the community, and make new friends.