Chris Coulson Email & Phone Number

At the start of this period, I moved from security engineering to a security focused role on the Ubuntu Foundations team, as part of Ubuntu engineering, although the scope of my role did not change.Before the move, I began to architect, design and began the integration of TPM protected FDE as part of Ubuntu Core desktop and the Ubuntu hybrid desktop offering. This included extra features such as the ability to add + remote TPM + PIN and TPM + passphrase keys, adding + removing recovery keys, improvements to the boot experience in this space, improvements to the install experience, improvements to repair / reprovision options and the integration of online re-encryption, integration of Landscape for recovery key backup.I also began the architecture of a method to perform firmware updates on Ubuntu Core without the use of recovery keys in the absence of metadata from OEMs where it isn't possible to predict PCR values.I began my long term vision for Ubuntu Core, which I would be expecting to be responsible for architecting. This includes moving to a fully verified and fully attestable runtime (including all code and security relevant configuration), providing appliance developers a way to restrict what apps a device can execute (even if they have valid signatures) or locking a device to a specific model in a way that is protected from the root user, integrity and rollback protection of locally protected data (eg, config, system data, user data), integration of virtualization based security, dynamic launch on CPUs that support DRTM, redesign of the boot stack, no MOKs etc.

I was responsible for architecting, implementing and integrating TPM protected FDE into Ubuntu Core. This involved the creation of an extensive design document, the presentation of this to the CEO and the implementation of this work across several go repositories, including the creation of a native go library for communicating with TPM2 devices, and a library implementing most of the FDE functionality, consumed directly by snapd. The design included the use of sealed objects protected by measured boot against changes to the early boot environment, represented by arbitrarily complex combinations of PCR values (with multiple branches), and prediction of PCR values based on updated boot artefacts and EFI signature database updates in a way that made updates atomic (in order to avoid the need for a recovery key if updates were interrupted). This required some upstream work in shim to fix some bugs.The project is architected to be agnostic of the underlying platform, so it works with Arm based platforms that may rely on other mechanisms to protect keys.I also performed some Linux kernel work, both on AppArmor, and via the development of a DM target that made use of the kernel's blk-crypto functionality (internally called dm-blk-crypto) to make it possible to use full-disk encryption (as opposed to file based encryption) with devices that contain hardware inline crypto engines. I convinced a customer to adopt the solution I proposed instead of the one they developed in house, which made no use of the kernel's existing functionality in this space.We engaged with public clouds to enable confidential computing features, being the first launch partner with AMD SEV-SNP images with TPM-protected full-disk encryption with Azure.I spent time preparing Ubuntu's openssl for FIPS140-3 certification.I was also involved with discovering multiple vulnerabilities in Grub, starting with the initial BootHole round of vulnerabilities.

I joined the security team with the mission to provide a secure, maintainable webview as part of the UI Toolkit for the Ubuntu Phone project. At the time, the Ubuntu archive had various forks of WebKit in it (eg, ones based on GTK and one based on Qt). These upstream projects generally didn't maintain release branches long term, making it hard to provide a secure base for a webview library and leaving us having to backport complex patches for the life of a release from an ever divergent codebase and without being able to keep up-to-date with the evolution of the web platform.We decided to build a new webview library based on the Chromium content API with a QML frontend that could be integrated into the Ubuntu UI toolkit. This project became known as "Oxide" and we provided a stable API that followed the Chromium release schedule, incorporating all of the Chromium security fixes and the changes it adopted as it evolved to changes to the web platform. The project was architected in a way to make it possible to add a future GTK frontend, although this never happened before the project was cancelled. The project made extensive use of C++, QML, Qt, QtQuick and Javascript, with an extensive test suite of the public API based on QtQuick Test and a growing internal unit test suite based on GoogleTest when the project was cancelled.This project was architected and created before qtwebengine, which was a webview library based on Chromium that was part of the Qt project.The project was eventually cancelled in 2017 with the Ubuntu Phone project and Unity 8.As part of my role, I was responsible for security response work (updating software that we shipped when affected by vulnerabilities) and code auditing.I have extensive knowledge of typical security disclosure practices.Amongst bugs I found, included a RCE vulnerability in systemd-resolved due to specially crafted DNS packets and a DoS vulnerability in systemd (PID1) caused by specially crafted dbus payloads.

Responsible for maintaining the Firefox and Thunderbird debian packages in Ubuntu, keeping them up-to-date and quickly providing regular updates as they were released upstream, working closely with upstream developers and our internal security team. Also performed extensive work to integrate both Firefox and Thunderbird with the Unity desktop - particularly the global menubar, and upstream work to integrate them with GNOME3 technologies in general. Worked with Thunderbird developers to provide an extension to integrate Thunderbird with the Unity notifications and launcher bar (to display new message counts on the Thunderbird launcher icon).My role coincided with Mozilla's change to their release schedule, from doing occasional major releases with long periods between each release, to performing regular major updates that introduced new features every few weeks. In order to accommodate enterprise environments, Mozilla introduced a ESM channel with a longer support period, which was adopted by most Linux distributions. I made the decision to adopt the mainline release schedule (not ESM) in Ubuntu because I believed our users would appreciate receiving features faster, and I believed it unfair that our users shouldn't receive these features in a timely fashion because of the additional impedance introduced by our application distribution mechanism (the fact that application distribution depended on Ubuntu developers). In order to be able to release updates in a timely fashion with all of the customizations we maintained, I maintained packaging streams for the various Mozilla release channels (at the time time - beta, Aurora and nightly, although these changed periodically over time), so that our customizations could be developed iteratively alongside Mozilla's development and release schedule.My role involved general desktop packaging work, and extensive understanding of the lower-level parts of the GNOME platform as well.

Redditch, United Kingdom

Haldex supply ABS and electronic braking products to the commercial vehicle sector. I worked within a very small electronics hardware team, responsible for the design and qualification of multiple braking products.My joining this team coincided with the start of the financial downturn, and my employer took this opportunity to close their local manufacturing facility, outsourcing of this work to other facilities. As a consequence, a lot of the work involved the preparation of formal documents that another facility could use to manufacture products.- I was also involved with a component obsolescence problem with a product that was 10 years old. I was responsible for choosing a suitable replacement, implementing the required design changes and performing the required re-validation work.- I was also involved with cost-reduction activities on existing products, including design changes to accommodate lower cost components, assembly of prototypes to perform preliminary validation, and documenting PCB layout requirements to facilitate an external contractor to make the required changes.- I was also involved with the thermal modelling of power components dissipating low continuous power but high pulsed power using dynamic SPICE thermal models.

Solihull, United Kingdom

TRW Automotive were a major supplier to the global automotive industry (now acquired by ZF). I worked within a hardware team responsible for the design and validation of electric power-assisted steering systems. The site I worked at also developed early prototypes of fully electric steering systems.- I was involved with coordinating and performing a design validation program to the requirements of the customer as a response to iterations in hardware design.- I gained a fairly significant understanding of brushless motor control techniques (particularly SVM) and high-power electronics design techniques (in particular, thermal management in applications that consume in excess of 100A).- I was involved with investigating validation test failures.- I was involved with system investigations to determine the cause of intermittent fault codes, working closely with the software team and making use of the Vector suite of tools for interacting with the CAN bus.- I left with an appreciation for how little margin there is in high volume automotive supply chains.

Birmingham, United Kingdom

Goodrich Engine Control Systems were a designer, manufacturer and supplier of FADEC (Full Authority Digital Engine Controls) systems to Rolls Royce engines. The company is now part of Rolls Royce.At the time I worked for them, they developed high-reliability engine-control systems for the aerospace industry. I worked within a hardware design team for small and large engine Electronic Control Systems. I was involved with three different products, working amongst both small and large teams of engineers and at different phases of the product life-cycle.- I was involved with EMC qualification testing of a FADEC system to RTCA/DO-160D.- I was responsible for investigation work performed because of failures during the qualification program. Developed, implemented and tested design changes to meet EMC requirements. Developed problem solving skills and good understanding of EMC design principles.- I investigated and solved a system integration issue at a critical phase of the development programme. Developed and tested hardware changes and recommended software solutions. Verified the affected interfaces over full operating envelope to guarantee in-service robustness - working closely with the customer throughout.- Design of analogue circuit functions and lightning-strike protection used in a large engine electronic controller.- Layout and tracking of a large PCB for a product currently in development. The product did not exhibit any problems related to the PCB layout during any design assurance or qualification tests (including EMC and lightning strike tests by the time I had left the company).