Encryption is vital

June 7th, 2017 by


We refuse to bid for government IT work because we can’t handle the incompetence.

At Mythic Beasts we make use of free secure encryption all the time. Like all powerful tools such as roads, trains, aeroplanes, GPS navigation, computers, kitchen knives, vans and Casio watches; things that are very useful for day to day life are also useful for criminals and terrorists. It’s very popular for our politicians and the Home Office, especially our current prime minister King Canute Theresa May and leader of The Thick Party, to suggest that fully secure encryption should be banned and replaced with a weaker version that will reveal all of your secrets but only to the UK security services.

We disagree and think this is a terrible idea. There’s the basic technical objection that a backdoor is a backdoor and keeping knowledge of the backdoor secret is essentially impossible. There’s a recent practical demonstration of this: the NSA knew of an accidental backdoor in Windows and kept it secret.  It was leaked, resulting in the thankfully not very effective WannaCry virus which disabled substantial fractions of the NHS. The government is very good at scope creep: the Food Standards Agency refused to disclose why it needs the power to demand your entire internet history. We think it fundamentally wrong that MPs excluded themselves from the Investigatory Powers act. Then there’s simple commercial objections: it’s a slight commercial disadvantage if every UK product has an ‘Insecure By Order of The Home Office’ sticker on the front when your foreign competitors products don’t.

However, Mathematics does not care what our politicians wish and refuses to change according to their desires. Strong cryptography is free, available on every computer, and can be given away on the front of a magazine. Taking away secure cryptography is going to involve dragging a playstation out of your teenagers’ hands, quite literally stealing from children. Of course secure communications will still be available to any criminal who can illegally access some dice and a pencil.

It’s a good job you can’t build encryption machines with childrens toys.

At Mythic Beasts we make extensive use of open source free cryptography. OpenSSH protects our administrative access to the servers we run and the customers we manage. OpenSSL protects all our secure web downloads, including last month’s million or so copies of Raspbian ensuring that children with a Raspberry Pi don’t have their computer compromised. We make extensive use of free certificates through Let’s Encrypt and we’ve deployed tens of thousands of upgraded packages to customers which are securely verified by GnuPG.

Without these projects, vast quantities of the internet would be insecure. So we’ve made donations to OpenSSH, GnuPG and Let’s Encrypt to support their ongoing work. We’d like to donate to OpenSSL but we can’t see easily how to pay from a UK bank account.

Save the Black Horse

May 26th, 2017 by

The last pub in Dry Drayton has closed and is under threat of development. As a community, we’re working hard to save it.

It’s Beer Festival week in Cambridge. Suddenly official work takes a back seat compared to the importance of drinking, serving and appreciating fine beer in the sunshine. It’s great that the volunteers behind the bar include friends, colleagues, customers, suppliers and the occasional former MP.

However, for 51 weeks of the year the Cambridge Beer Festival isn’t operating and beer lovers among us have to go to a more humble establishment, the pub. Cambridge City is blessed with multiple excellent pubs, but occasionally it’s nice to take a visit to the outlying villages.

So we were very saddened to hear that the only pub in Dry Drayton, the Black Horse, was due to close. However, a community group has started assembling plans to turn it into a community pub on a similar model to the excellent Dykes End in Reach. They asked us to help with setting up their on-line presence. Mythic Beasts fully support the effort to have lovely pubs within walking and cycling distance so we’ve provided a Managed WordPress site to help their campaigning efforts. Today we’ll share a beer with them in the Beer Festival, and in the near future we hope to take a field trip to their re-opened countryside pub.

Update: They reported last night they’ve had a lot of signups to their newsletter and several interested investors. It looks like we’re going to be part of a successful pub rescue!

 

Cambridge Beer Festival, Raspberry Pi powered Apps for Beer

May 22nd, 2017 by

We drew the architecture diagram for the beer festival on a beer mat.

Today marks the first day of the Cambridge Beer Festival, the longest running CAMRA beer festival, one of the largest beer festivals in the UK and in our obviously correct opinion, by far the best. Not only have we run the web back-end for many Cambridge CAMRA websites for many years, this year we’ve been involved with Cambridge App Solutions who run the iPhone Beer Festival App. They’d been having some trouble with their existing hosting provider for the back-end. In frustration they moved it to their Cloud Raspberry Pi which worked rather better. They then suggested that we keep the production service on the Raspberry Pi, despite it being a beta service.

Preparing for production

We’ve set up all our management services for the hosted Pi in question, including 24/7 monitoring and performance graphing. We then met up with Craig, their director in the pub to discuss the app prior to launch. The Pi 3 is fronted by CloudFlare who provide SSL. However, the connection to the Pi3 from Cloudflare was initially unencrypted. We took Craig through our SSL on a Raspberry Pi hosting guide and about a minute later we had a free Let’s Encrypt certificate to enable full end-to-end data security.

 

 

The iPhone app that runs the Cambridge Beer Festival (also found at Belfast and Leestock)

 

The iPhone Beer Festival App tracks which beers are available and the ratings for how good they are. Availability is officially provided, ratings are crowd sourced.  The app is continuously talking to the back end to keep the in app data up to date. All this data is stored and served from the Raspberry Pi 3 in the cloud.

Proximity

The festival also has some Estimote beacons for proximity sensing which use Bluetooth Low Energy to provide precise location data to the phone. On entry to the beer festival the app wakes up and sends a hello message.

Raspberry Pi Cloud upgrades

May 12th, 2017 by

We’ve made some improvements to our Raspberry Pi Cloud.

  • Upgraded kernel to 4.9.24, which should offer improved performance and a fix for a rare crash in the network card.
  • Minor update to temperature logging to ease load on our monitoring server and allow faster CPU speeds.
  • Upgrade to the NFS fileserver to allow significantly improved IO performance.
  • Recent updates applied to both Debian and Ubuntu images.

Thanks to Gordon Hollingworth, Raspberry Pi Director of Engineering for his assistance.


Upgraded backups

March 31st, 2017 by

Servers need different backup strategies to Vampire Slayers.

Our backup report caught a warning from the backup on our monitoring server:

WARN - [child] mysqldump: Error 2013: Lost connection to MySQL server during query when dumping table `log` at row: 6259042
....
ERROR - mysqldump --all-databases .... exited with 3

We investigated, indeed this is an error and we’ve created a truncated backup. As we think backups are very important we investigated immediately rather than adding it to the end of a very long task list that would be ignored in favour of more user visible changes.

An initial guess was that it might be a mismatch in max_allowed_packet between the server and the dump process, a problem that we’ve seen before. We set max_allowed_packet for mysqldump to the maximum allowed value, reran the backup manually and watched it fail again. Hypothesis disproven and still no consistent backup.

Checking the system log, it quickly became apparent that we were running out of memory. The out of memory killer had kicked in and decided to kill mysqld (an unfortunate choice, really). This was what had caused the dump to terminate early.

Now we understand our problem, one solution is to configure a MySQL slave and back up from the slave, another is to move to a bigger MySQL server, another is to exclude the ephemeral data from the backup. We chose to exclude the ephmeral data and now our backup is complete and we’ve tested the restore.

While working on this, our engineer noticed that there was an easy extra check we could make to ensure the integrity of a MySQL dump. When the dump is complete we run the moral equivalent of:

zcat $dump | tail -1 | grep -q '^-- Dump completed'

to check that we have a success message at the end of the dumped file. This is an additional safety check. Previously we were relying on mysqldump to tell us if it found an error, now we require mysqldump to report success and the written file to pass automated tests for completeness.

We pushed out our updated backup package with the additional check to all managed customers yesterday. On World Backup Day, we’d like to remind the entire Internet to check that your backups work. If that sounds boring, we’ll check your backups for you.

One click HTTPS + HSTS

March 27th, 2017 by

Last year we rolled out one-click HTTPS hosting for our hosting accounts using free Let’s Encrypt certificates.  We’ve been making some further improvements to our control panel so that once you have enabled and tested HTTPS hosting, it’s also easy to redirect all HTTP traffic to your HTTPS site.

We’ve also added an option to enable HTTP Strict Transport Security (HSTS).  This allows you to use HTTPS on your website and commit that you’re not going to stop using it any time soon (we use 14 days by default).  Once a user has visited your site their browser will cache the redirect from HTTP to HTTPS and will automatically redirect any future requests without even visiting the HTTP version of your site.

HSTS makes it harder for an attacker to impersonate your site as even if they can intercept your traffic, they won’t be able to present an non-HTTPS version of your site to any user that has visited your site within the last 14 days.

HTTPS and HSTS control panel settings

We believe that the web should be secure by default, and hope that these latest changes will make it that little bit easier to secure your website.  These features are available on all of our web and email hosting accounts.  We’ll also happily enable this as part of the service for customer of our managed server hosting.

 

PHP7 on Pi 3 in the cloud (take 2)

March 24th, 2017 by

On Wednesday, we showed you how to get PHP7 up and running on one of our Pi 3 servers. Since then, we’ve implemented something that’s been on our to do list for a little while: OS selection. You can now have Ubuntu 16.04 and the click of a button, so getting up and running with PHP7 just got easier:

1. Get yourself a Pi 3 in our cloud.

2. Hit the “Reinstall” button:

3. Select Ubuntu 16.04:

4. Upload your SSH key (more details), turn the server on, SSH in and run:

apt-get install apache2 php7.0 php7.0-curl php7.0-gd php7.0-json \
    php7.0-mcrypt php7.0-mysql php7.0-opcache libapache2-mod-php7.0
echo "<?=phpinfo()? >" >/var/www/html/info.php

Browse to http://www.yourservername.hostedpi.com/info.php and you’re running PHP7:

PHP7 on a Raspberry Pi 3 in the cloud

March 22nd, 2017 by
Rasberry Pi 3

Two Raspberrys PI using PHP7 during the Pi 3 launch.

Last April we moved the main blog for Raspberry Pi to a small cluster of Raspberry Pi 3s. This went so well we made it commercially available and you can now buy your Raspberry Pi 3 in the cloud.

If you’d like to have PHP 7 running on your Raspberry Pi 3 in the cloud, this guide if for you. Click the link, buy a Pi 3 and install your ssh-key and log in. This should take no more than about a minute.

PHP 7 isn’t yet part of the standard Raspbian OS, so we need to get it from somewhere else.

A brief aside about CPU architectures, Raspbian and Debian

Debian provides three versions for ARM processors:

  • armel – 32 bit and ARMv5
  • armhf – 32 bit, ARMv7 and a floating point unit
  • arm64 – 64 bit ARMv8 and a floating point unit

The Raspberry Pi uses three different architectures:

  • Raspberry Pi A, B, Zero & Zero W – 32 bit ARMv6 with floating point
  • Raspberry Pi 2 – 32 bit ARMv7 with floating point
  • Raspberry Pi 3 – 32/64 bit ARMv8 with floating point unit

Raspbian is an unofficial port for 32bit ARMv6 and a floating point unit, which matches the hardware for an original Raspberry Pi model B. Because we’re working here with the Pi 3 – ARM8 and floating point, we can take official debian armhf packages and run them directly on our Pi 3.

Ondřej Surý is the Debian PHP maintainer who also has a private repository with newer versions of PHP built for Debian and Ubuntu. So we can use 32 bit Debian packages for ARM 7 (armhf) and install directly on top of Raspbian.

PHP 7 packages aren’t available for armel, so this won’t work on an original Raspberry Pi, or a Pi Zero/Zero W.

Add the PHP 7 repository

deb.sury.org includes newer PHP packages built for armhf, which we can use directly. Following the instructions here here we can set up the repository:

apt-get install apt-transport-https lsb-release ca-certificates
wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg
echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list
apt-get update

Now we can install everything we need for php7 and apache2.4:

apt-get install apache2 php7.0 php7.0-curl php7.0-gd php7.0-json \
    php7.0-mcrypt php7.0-mysql php7.0-opcache libapache2-mod-php7.0
echo "<?=phpinfo()?>" >/var/www/html/info.php 

Wait a few moments and we have a webserver running PHP7 on our Pi3 in the cloud.

You’ll note we’ve included php7-opcache. This should accelerate our PHP performance by a factor of two or so.

Now for an application…

Try WordPress

WordPress needs a MySQL server & PHP library for accessing MySQL. We need to restart Apache to make PHP 7 pick up the additional library.

apt-get install php7.0-mysql  mysql-server
apache2ctl restart
mysql -u root -p

mysql> create database wordpress;
mysql> grant all privileges on wordpress.* to wordpress identified by 'password';

We strongly recommend you invent a better password.

cd /var/www/html
wget https://wordpress.org/latest.tar.gz
tar -zxvf latest.tar.gz
chown -R www-data:www-data wordpress

Then navigate to http://www.yourpiname.hostedpi.com/wordpress and finish the install through your browser.

Next steps

For information on how to host on your own domain name, and how to enable HTTPS see our previous blog post on hosting a website on a Raspberry Pi.

Hosting a website on an IPv6 Pi part 2: PROXY protocol

March 10th, 2017 by

In our previous post, we configured an SSL website on an IPv6-only Raspberry Pi server, using our IPv4 to IPv6 reverse proxy service.

The one problem with this is that our Pi would see HTTP and HTTPS requests coming from the proxy servers, rather than the actual clients requesting them.

Historically, the solution to this problem is to have the proxy add X-Forwarded-For headers to the HTTP request, but this only works if the request is unencrypted HTTP, or an HTTPS connection that is decrypted by the proxy. One of the nice features of our proxy is that it passes encrypted HTTPS straight to your server: we don’t need your private keys on the proxy server, and we can’t see or interfere with your traffic.

Of course, this means that we can’t add X-Forwarded-For headers to pass on the client IP address. Enter PROXY protocol. With this enabled, our proxies add an extra header before the HTTP or HTTPS request, with details of the real client. This is easy to enable in our control panel:

You also need to configure Apache to understand and make use of the PROXY protocol header. This is a little more involved, as the necessary module isn’t currently packaged as part of the standard Apache distribution (although this is changing), so we need to download and build it ourselves. First some extra packages are needed:

apt-get install apache2-dev git

This will install a good number of packages, and take a few minutes to complete. Once done, you can download, install and build mod_proxy_protocol

git clone https://github.com/roadrunner2/mod-proxy-protocol.git
cd mod-proxy-protocol
make

At this point you should just be able to type make install but at time of writing, there seems to be some problem with the packaging. So instead do this:

cp .libs/mod_proxy_protocol.so /usr/lib/apache2/modules/

Now you can load the module:

echo "LoadModule proxy_protocol_module /usr/lib/apache2/modules/mod_proxy_protocol.so" > /etc/apache2/mods-available/proxy_protocol.load
a2enmod proxy_protocol

You also need to configure Apache to use it. To do this, edit /etc/apache2/sites-enabled/000-default.conf and replace each line that contains CustomLog with the following two lines:

	ProxyProtocol On
	CustomLog ${APACHE_LOG_DIR}/access.log "%a %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""

This tells Apache to use Proxy Protocol, and to use the supplied IP address in its log files. Now restart Apache:

systemctl reload apache2

Visit you website, and if all is working well, you should start seeing actual client IP addresses in the log file, /var/log/apache2/access_log:

93.93.130.44 - - [24/Feb/2017:20:13:25 +0000] "GET / HTTP/1.1" 200 10701 "-" "curl/7.26.0"

Trusting your log files

With the above configuration, we’ve told Apache to use the client IP address supplied by our proxy servers. What we haven’t done is told it that it can’t trust any random server that pitches up talking PROXY protocol. This means that it’s trivial to falsify IP addresses in our log files. To prevent this, let’s set up a firewall, so that only our proxy servers are allowed to connect on the HTTP and HTTPS ports. We use the iptables-persistent package to ensure that our firewall is configured when the server is rebooted.

apt-get install iptables-persistent

ip6tables -A INPUT -s proxy.mythic-beasts.com -p tcp -m tcp --dport 80 -j ACCEPT
ip6tables -A INPUT -s proxy.mythic-beasts.com -p tcp -m tcp --dport 443 -j ACCEPT
ip6tables -A INPUT -p tcp --dport 80 -j REJECT
ip6tables -A INPUT -p tcp --dport 443 -j REJECT

ip6tables-save

And we’re done! Our IPv6-only Raspberry Pi3 is now hosting an HTTPS website, and despite being behind a proxy server, we’re tracking real client IP addresses in our logs.

One-click SPF

March 9th, 2017 by

Sender Policy Framework (SPF) has been around for a while, but recently we’ve seen email providers getting much more active in using it to filter mail. Most notably, Gmail appearing to be flagging mail from all domains without an SPF record as untrusted.

In a nutshell, SPF allows you to publish a DNS record that declares a list of all of the mail servers that may legitimately send mail from your domain. It’s not perfect, but it’s a useful tool in reducing email with a forged sender address.

Getting SPF records right can be a bit tricky, but for domains hosted with Mythic Beasts that send mail exclusively via our mail servers, you can now add the correct SPF record with a single click.

One-click SPF enablement

The SPF settings are available on the domain pages in our control panel.

We’d love to make it even easier and just add the record for you, but we can’t be sure that customers are only using our mail servers to send mail, and if not, adding the record will make things worse, although we are planning to add this record by default for newly hosted domains.

It’s worth noting that SPF does not cause problems when sending mail via mailing lists as all decent mailing list software will use its own sender address rather than yours. You may be aware of a change made by Yahoo! that caused considerable problems for mailing lists, but this was related to another system, DMARC, which builds on top of SPF. SPF on its own works just fine with mailing lists.