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TLS/SSL Test Suite for Mozilla Firefox

Project description

TLS Canary

Status : Archived

This project is no longer maintained and has been archived. No further work will be done on it including security fixes. Feel free to fork the project if you'd like to extend it.


TLS Canary was a TLS/SSL testing framework for the Mozilla Firefox web browser. It was used by developers to run regression and performance tests against a large number of HTTPS-enabled hosts on the Internet.

License PyPI Package version

This project

  • Downloads a test build and a base build of Firefox for comparison.
  • Automatically queries thousands of secure sites with those builds.
  • Diffs the results and presents potential regressions in an report for further diagnosis.
  • Does performance regression testing.
  • Extracts SSL state information.
  • Can also use local Firefox build trees or package files for testing.
  • Can maintain an updated list of HTTPS-enabled top sites.
  • Requires a highly reliable network link. WiFi will give unstable results.


  • Python 3.6+
  • 7zip
  • Go 1.7 or later
  • Rust 1.39 or later
  • OpenSSL-dev
  • libffi-dev

Dependencies for Debian and Ubuntu users

Assuming that you run TLS Canary on a regular graphical desktop machine, these are the packages it requires:

sudo apt-get install python3 python3-dev gcc golang-1.9-go p7zip-full libssl-dev libffi-dev libx11-xcb-dev

In addition, you'll need to install the Rust Cargo toolchain:

curl --proto '=https' --tlsv1.2 -sSf | sh

The script provides bootstrapping for a headless Ubuntu-based EC2 instance which requires installation of a few standard GUI libraries for running Firefox. The script may or may not work for your other favourite Debian-based distribution.

Dependencies for Mac users

Assuming that your're using Homebrew for package management, this should set you up:

brew install openssl libffi python p7zip go

The script provides bootstrapping for Travis CI's Mac OS X instances using homebrew for package management. It may work for your OS X desktop environment as well.

Dependencies for Windows users

Windows support targets PowerShell 5.1 on Windows 10. Windows 7 and 8 are generally able to run TLS Canary, but expect minor unicode encoding issues in terminal logging output.

First, install Chocolatey, then run the following command in an admin PowerShell to install the dependencies:

choco install 7zip.commandline git golang openssh python3

For end users

TLS Canary can be installed as a stable package from PyPI and as experimental package directly from GitHub. The following command will install the latest stable release of TLS Canary to your current Python environment:

pip3 install [--user] --upgrade tlscanary

Whether or not you require the --user flag depends on how your Python environment is set up. Most Linux distributions require it when not installing Python packages as root.

Once it finishes the tlscanary binary is available in your Python environment:

tlscanary --help
tlscanary regression --help
tlscanary log --help

Usage examples

# Run a quick regression test against the first 50000 hosts in the default `top` database
tlscanary regression -l 50000

# Compile a fresh 'top 1000' host database called `mini`
tlscanary srcupdate -s mini -l 1000 -x1

# Show a list of available host databases
tlscanary srcupdate -s list

# Use your fresh `mini` database for a quick regession test and see lots of things happening
tlscanary --debug regression -s mini

Please refer to the complete argument and mode references below.

Run log and reporting

TLS Canary collects all run log data in ~/.tlscanary/log. The format is somewhat JSONny, but heavily compressed to save disk space. Canary logs can get very big very fast when a run returns many results.

Here are some usage examples how to interact with TLS Canary's run log database:

# List all logs in database, including incomplete ones marked with (*)
tlscanary log

# List and then delete incomplete logs
tlscanary log -i incomplete
tlscanary log -i incomplete -a delete  # just a dry-run
tlscanary log -i incomplete -a delete --really

# Print complete regression logs as JSON array to terminal
tlscanary log -i regression -e incomplete -a json

# Print JSON report of the last two runs to terminal
tlscanary log -i 2 -a json

# Create an HTML report in /tmp/report for completed regression runs
tlscanary log -i regression -e incomplete -a htmlreport -o /tmp/report

Canary run modes

Run modes are specified via the mandatory positional mode parameter. See tlscanary <mode> --help for mode-specific arguments.

Mode Description
log Performs various actions on run logs collected by performance, regression, and scan runs. See tlscanary log --help.
performance Runs a performance analysis against the hosts in the test set. Use --scans to specify how often each host is tested.
regression Runs a TLS regression test, comparing the 'test' candidate against the 'baseline' candidate. Only reports errors that are new to the test candidate. No error generated by baseline can make it to the report.
scan This mode only collects connection state information for every host in the test set.
srcupdate Compile a fresh set of TLS-enabled 'top' sites from the Umbrella Top 1M list. Use -l to override the default target size of 500k hosts. Use -x to adjust the number of passes for errors. Use -x1 for a factor two speed improvement with slightly less stable results. Use -b to change the Firefox version used for filtering. You can use -s to create a new database, but you can't make it the default. Databases are written to ~/.tlscanary/sources/.

Command line arguments for test runs

The run modes performance, regression, and scan share a common set command line arguments:

Argument Choices / default Description
-b --base release, nightly, beta, aurora, esr, build tree, package file Baseline test candidate to test against. Only used by comparative test modes.
-c --cache false Enable content caching in profiles
-d --debug Enable verbose debug logging to the terminal
-f --filter 0, 1 The default filter level 1 removes network timeouts from reports which may appear spuriously. Filter level 0 applies no filtering.
-h --help Longer usage information
-j --parallel 4 Number of parallel firefox worker instances the host set will be distributed among
-l --limit 100000 The number of hosts in the test set is limited to the given number. Default is 100000 hosts. You can increase the limit, but such runs will require LOTS of memory (90 GBytes and more) and can cause instability.
-m --timeout 10 Request timeout in seconds. Running more requests in parallel increases network latency and results in more timeouts.
-n --requestsperworker 50 Chunk size of hosts that a worker will query in parallel.
-o --onecrl production, stage, custom OneCRL revocation list to install to the test profiles. custom uses a pre-configured, static list.
-s --source top, list, ... Set of hosts to run the test against. Pass list to get info on available test sets.
-t --test release, nightly, beta, aurora, esr, build tree, package file Specify the main test candidate. Used by every run mode.
-u --max_timeout 20 Maximum request timeout in seconds. Each scan increases the timeout, up to this value
-w --workdir ~/.tlscanary Directory where cached files and other state is stored
-x --scans 3 Number of scans to run against each host during performance or regression mode.
MODE performance, regression, scan, srcupdate Test mode to run, given as positional parameter. This is a mandatory argument.

For developers

For development you will additionally need to install:

  • git
  • virtualenv (highly recommended)

git can be installed with your favourite package manager. virtualenv comes with a simple pip install [--user] virtualenv.

Developing on Linux or Mac

These are the commands that set you up for TLS Canary development work:

git clone
cd tls-canary
virtualenv -p python3 venv
source venv/bin/activate
pip install -e .[dev]

The latter command should be used regularly to install new Python dependencies that a TLS Canary update might require.

Developing on Windows

Developing TLS Canary on Windows is not something we practice regularly. If you encounter quirks along the way, please do not hesitate to open an issue here on GitHub. The following commands, executed in a PowerShell session with user privileges, should set you up for TLS Canary development:

git clone
cd tls-canary
virtualenv -p c:\python36\python.exe venv
pip install -e .[dev]

Building and running tls-canary

python build
python install

Running tests

There are two ways to run the test suite:

python test
nosetests -v

They are largely equivalent, but the former takes care of missing test dependencies, while running nosetests directly offers more control. To get test coverage, for example, use

nosetests -v --with-coverage --cover-erase --cover-package=tlscanary

Installing the pre-commit hook for git

There's a pre-commit hook for git that you can use for automated PEP 8 violations checking. You can install it by running

ln -sf ../../hooks/pre-commit .git/hooks/

in the top-level project directory. By using a symbolic link, you will automatically get updates once the hook in the repo changes. This is highly recommended. You can also copy the script manually, but then you have to take care of updates yourself.

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