2FA and User Session Management in IXP Manager

We’ve just released IXP Manager v5.3.0. The headline feature in this release is two-factor authentication (2fa) and user session management. This blog post overviews the PHP elements on how we did that.

While IXP Manager is a Laravel framework application, it uses Doctrine ORM as its database layer via the Laravel Doctrine bridge. For those curious, this really is a carry over from when IXP Manager was a Zend Framework application. For the migration, we concentrated on the controller and view elements of the MVC stack leaving the model layer on Doctrine. Over time we’ll probably migrate the model layer over to Laravel’s Eloquent.

Before reading on, it would be useful to first read the official documentation we have written aroud 2fa and user session management:

Hopefully the how we did this will be useful for anyone else in the same boat or even just trying to understand the Laravel authentication stack.

Two factor authentication (2fa) strengthens access security by
requiring two methods (also referred to as factors) to verify your
identity. Two factor authentication protects against phishing, social
engineering and password brute force attacks and secures your logins
from attackers exploiting weak or stolen credentials.

User session management allows a user to be logged in and remembered from multiple browsers / devices and to manage those sessions from within IXP Manager.

For 2fa, we used the antonioribeiro/google2fa-laravel package which is built on antonioribeiro/google2fa. If we were 100% in Laravel’s eco-system the would have been easier but because we use Doctrine, we needed to override a number of classes.

Structurally we need a database table to indicate if a user has 2fa enabled and to hold their 2fa secret – for this we created Entities\User2FA. Similarly, we have a controller to handle the UI interaction of enabling, configuring and disabling 2fa: User2FAController – this also includes generating QR codes for the typical 2fa activation process.

On the user session management side, we created Entities\UserRememberToken to hold multiple tokens per user (rather than Laravel’s default single token in a column in the user’s user database entry. For the frontend UI, UserRememberTokenController allows a user to view their active sessions and invalidate (delete) them if required.

The actual mechanism of enforcing 2fa is via middleware: IXP\Http\Middleware\Google2FA. This is added, as appropriate, to web routes via the RouteServiceProvider. This will check the user’s session and if 2fa is enabled but has not been completed, then the middleware will enforce 2fa before granting access to any routes covered by it.

Note that because we also implemented user session management via long-lived cookies and because the fact that a user has passed 2fa or not is held in the session, we need to persistently store the fact in the user’s specific remember token database entry. This is done via the Google2FALoginSucceeded listener. This is then later checked in the SessionGuard – where, if we log a user in via the long-lived cookie, we also make them as having passed 2fa if so set.

Speaking of the SessionGuard, this was one of the bigger changes we had to make – we overrode the Illuminate\Auth\SessionGuard as we needed to replace a few functions to make 2fa and user session management work. We have kept these to a minimum:

  1. The user() function – Laravel’s long lived session uses a single token but we require a token per device / browser. We also need to side-step 2fa for existing sessions as discussed above and allow for features such as allowing a user to delete other long-lived sessions and to provide functionality to allow these sessions to expire.
  2. The ensureRememberTokenIsSet() to actually create per-browser tokens (and to expire old ones).
  3. The queueRecallerCookie() so we can insert our own token rather than the default Laravel version.
  4. The cycleRememberToken() which is actually used to invalidae a token by changing it in Laravel. We override to delete the token.

Similarly we have to override the DoctrineUserProvider class to:

  1. Change retrieveByToken() to use our new database in which a user may have multiple sessions across different browsers / devices.
  2. Add addRememberToken() and purgeExpiredRememberTokens() to add and remove tokens.

We of course had to ammend the AuthServiceProvider to use our new overridden classes.

The above constitutes a bulk to the changes. Because 2fa can be enforced via middleware, it doesn’t really touch the core Laravel authentication process. The user session management was more invasive and responsible for the bulk of the changes required in the DoctrineUserProvider and SessionGuard.

What’s not mentioned above is the views – these are mainly covered in the views/user-remember-token (with a lot of inheritence from views/frontend) and the views/user/2fa directories.

While there are a lot more changes between v5.2.0 and v5.3.0 than 2fa and user session management, you can see the complete set of changes here.

Upgrading to PHP 7.3 on Ubuntu Bionic 18.04 LTS

Ubuntu 18.04 ships with PHP 7.2 by default but there are various reasons why you may wish to upgrade to newer versions. For example, active support for it ends later this year – far sooner than the 2023 support window for the OS.

In addition, applications will be released that will require newer versions in that 2018 – 2023 window. For IXP Manager, we are releasing v5 this month and mandating PHP 7.3 support. We do this to stay current and to prevent developer apathy – insisting on legacy frameworks and packages that have been EOL’d provides a major stumbling block for bringing on new developers and contributors. There’s also a real opportunity cost – I have a couple free hours, will I work on project A or project B? If project A uses an old stale toolchain where everything is that much more awkward that project B then which would you choose?

So, from a typical LAMP stack install of Ubuntu 18.04, you’ll find something like the following packages for PHP:

root@ubuntu:/var/www/html# dpkg -l | grep php | cut - -b 1-65
 ii  libapache2-mod-php                    1:7.2+60ubuntu1
 ii  libapache2-mod-php7.2                 7.2.17-0ubuntu0.18.04.1
 ii  php-common                            1:60ubuntu1
 ii  php-mysql                             1:7.2+60ubuntu1
 ii  php7.2-cli                            7.2.17-0ubuntu0.18.04.1
 ii  php7.2-common                         7.2.17-0ubuntu0.18.04.1
 ii  php7.2-json                           7.2.17-0ubuntu0.18.04.1
 ii  php7.2-mysql                          7.2.17-0ubuntu0.18.04.1
 ii  php7.2-opcache                        7.2.17-0ubuntu0.18.04.1
 ii  php7.2-readline                       7.2.17-0ubuntu0.18.04.1

Obviously your exact list will vary depending on what you installed. I find the easiest way to upgrade is to start by removing all installed PHP packages. Based on the above:

dpkg -r libapache2-mod-php libapache2-mod-php7.2 php-common   \
  php-mysql php7.2-cli php7.2-common php7.2-json php7.2-mysql \
  php7.2-opcache php7.2-readline

The goto place for current versions of PHP on Ubuntu is Ondřej Surý’s PPA (Personal Package Archive). Ondřej maintains this in his own time so don’t be afraid to tip him here.

It’s easy to add this to 18.04 as follows:

add-apt-repository ppa:ondrej/php
apt-get update

Then install the PHP 7.3 packages you want / need. For example we can just take the package removal line above and install the 7.3 equivalents with:

apt install libapache2-mod-php libapache2-mod-php7.3 php-common \
    php-mysql php7.3-cli php7.3-common php7.3-json php7.3-mysql \
    php7.3-opcache php7.3-readline

And voilà:

php -v
 PHP 7.3.5-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: May  3 2019 10:00:24) ( NTS )

One post-installation check is to replicate and custom php.ini changes you may have made (max upload size, max post size, max memory usage, etc.).

Evaluating zsh

I’ve always been a bash user but I’ve recently decided to give zsh a while. It has some pretty useful features such as path expansion and replacement (see this slideshare). And yes, I’m well aware of bash-completion thank you very much.

It also has a nice eco system of expansions including oh-my-zsh with which I’m using plugins for git, composer (php), laravel5, brew, bower, vagrant, node and npm. I went with the agnoster theme and for iTerm2 (my terminal application of choice) I installed the Solarized Dark and Light themes. Both work well with the agnoster theme. I also installed and use the Meslo font.

One issue I did find immediately is things like file type colourisation with ls were not as good as bash. To resolve this, I installed the warhol plugin (as well as brew install zsh-syntax-highlighting grc). Now I find my ls’, ping’s, traceroute’s etc all nicely coloured.

We use Dropbox with work and to keep my work and home office laptops in sync, I moved the configs into Dropbox and symlinked to them:

cd ~
mv .oh-my-zsh Dropbox/ 
mv .zshrc Dropbox
ln -s Dropbox/.og-my-zsh
ln -s Dropbox/.zshrc

This all works really well. My bash aliases are fully compatible so I just pull them in at the end of .zshrc (source ~/.bash_aliases). Lastly – to prevent the prompt including my username and hostname on my local laptop, I set the following in .zshrc:

export DEFAULT_USER=barryo

So far, so happy.

PhpStorm and Xdebug – macOS / Homebrew

After many years of Sublime Text and, latterly, Atom, I’ve decided to give an integrated IDE another look – this time PhpStorm. I’ve always dropped them in the past as they tended to crash (hello Zend Studio) and were slow as hell (hello again Zend Studio). But so far so good – I’m only a couple days into an evaluation license but it’s fast (admittedly I have fast laptops – Intel i7’s with four cores, PCI SSD and 16GB RAM) and it’s yet to crash.

One of the key advantages of IDE’s is integrated debugging. This was ridiculously easy with PhpStorm. I use Homebrew for PHP:

$ brew ls --full-name

I’ve then configured xdebug as follows:

$ cat /usr/local/etc/php/7.1/conf.d/ext-xdebug.ini

If you’re not using Laravel’s Valet for local development then you should check it out immediately: https://laravel.com/docs/5.3/valet. If you are using it, issue a valet restart.

Port 9001 was chosen above as Valet tends to use 9000 also. We now need to reconfigure PhpStorm to list on this port. Open preferences and type xdebug into the search box. Then find Languages & Frameworks -> PHP -> Debug on the left hand navigation pane and change the port to 9001.

That’s pretty much it for PhpStorm. They really mean zero-configuration debugging. When editing a project in the IDE, there’s a Start Listening for PHP Debug Connections toggle icon in the top left – it looks like a phone. Just turn it on.

The last thing we need to do is have an easy way to enable Xdebug when we want it when testing our applications in the browser. Chrome has a very useful plugin for this: Xdebug-helper. Just install it and edit its options and change the IDE form Eclipse to PhpStorm. You can now use this to start a debug session from within Chrome to your listening PhpStorm IDE.

Oh, just found this useful resource also covering similar topics with a CGI/CLI xdebug split.

Linux (Ubuntu 16.04), PHP and MS SQL

In the many years I’ve been using the traditional LAMP stack, I’ve successfully managed to avoid having anything to do with MS SQL server. Until 2016. This year I’ve had to work quiet a bit with it – administration, backups and, now, scripted queries from Linux with PHP.

I suspect I’m (a) lucky I haven’t had to do this before now; and (b) that Azure seems to have pushed Microsoft into greater Linux based support for MS SQL. The evidence? This open source Mircosoft repository with a MS SQL PHP binary driver for Linux released just a few months ago.

NB: installing the Microsoft PHP driver is different to installing the Microsoft ODBC driver for SQL Server on Linux. These may even be incompatible.

For me, I just took a standard Ubuntu 16.04 install (64bit obviously) with PHP 7.0 and downloaded the latest MS PHP SQL extension (for me, at time of writing, this was 4.0.6. When you untar the Ubuntu16.tar file, copy the .so files to /usr/lib/php/20151012/ and then create a /etc/php/7.0/mods-available/msphpsql.ini file with contents:


Note that the tar also contains two ‘ts’ versions of these files. Trying to use those resulted in errors. Link this for Apache2 / CLI as required. E.g. for PHP CLI:

cd /etc/php/7.0/cli/conf.d/
ln -s ../../mods-available/msphpsql.ini 20-msphpsql.ini

You can confirm it’s working via:

$ php -i | grep sqlsrv
Registered PHP Streams => https, ftps, compress.zlib, php, file, glob, data, http, ftp, sqlsrv, phar
PDO drivers => sqlsrv
pdo_sqlsrv support => enabled
pdo_sqlsrv.client_buffer_max_kb_size => 10240 => 10240
pdo_sqlsrv.log_severity => 0 => 0
sqlsrv support => enabled
sqlsrv.ClientBufferMaxKBSize => 10240 => 10240
sqlsrv.LogSeverity => 0 => 0
sqlsrv.LogSubsystems => 0 => 0
sqlsrv.WarningsReturnAsErrors => On => On

And, finally, for using it, following the the sample scripts from the repository worked a charm.