ChasR is an open-source end-to-end encrypted GPS tracking system. It can be used directly as service or hosted by oneself. The goal of ChasR is to offer a privacy protecting GPS tracking service by using end-to-end encryption. This means that the sensitive location data of a user is directly encrypted on the device before it is sent to the server. Since the server does not know the key for the encryption, it cannot see the location data. The stored location data can be accessed either via Android App or web interface. Again, the location data is decrypted on the device and hence the server has no way of knowing the location of the user. All you need to use ChasR is a free account and ChasR logging application.

A diagram showing the ChasR architecture (a logger device for collecting the location data, the server that stores the encrypted data, and the map device showing the location data) looks like the following:

The ChasR GPS Tracking System is separated into multiple components:

Logger

• ChasR Android Logger (Github | Google Play)
• ChasR Linux Logger (Github)

Map

• ChasR Android Map (Github | Google Play)

Server

• ChasR Server (Github | Service)

Additionally, the ChasR GPS Tracking System can be used as part of the AlertR Alarm and Monitoring System (for example as a car alarm system).

This is the server component of the ChasR GPS Tracking System. Its task is to store the encrypted GPS data, providing access to it via a well defined API and to give the user access to the data via a map view. The server uses a MySQL database as backend to store the GPS data and OpenLayer with OpenStreetMap to provide a map view.

Installing the server is rather simple. It needs a MySQL server, a web server and PHP 7. You have to create a MySQL user for the server and a database for it. Place the project into your web root directory. Rename the configuration template file config/config.php.template to config/config.php and insert the needed information into it. Afterwards, browse to config/install.php to create the needed database layout.

To create a user you can use the config/add_user.php file. You have to set the values in this file to create the corresponding user.

All clients are written to use HTTPS for security reasons. Therefore, if you want to host the server yourself you have to configure your web server to serve HTTPS with a valid certificate.

You can create a docker image from the repository executing the command:

docker build -t chasr-server .

The docker image created is named chasr-server. The service can then be configured using environment variables. Available environment variables are:

• MYSQL_SERVER
• MYSQL_USERNAME
• MYSQL_PASSWORD
• MYSQL_DATABASE
• MYSQL_PORT
• SESSION_EXPIRE
• NUM_MIN_DEVICES
• NUM_MID_DEVICES
• NUM_MAX_DEVICES

Please refer to the configuration template file config/config.php.template for a description of these variables. After you started the container, browse to config/install.php to create the needed database layout.

If you like this project you can help to support it by contributing to it. You can contribute by writing tutorials, creating and documenting exciting new ideas to use ChasR (for example on the AlertR subreddit), writing code for it, and so on.

If you do not know how to do any of it or do not have the time, you can support the project by donating or support me on Patreon. Since the service has a monthly upkeep, the donation helps to keep these services free for everyone.