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Try SROS2 in MacOS

Install OpenSSL

Install a recent version of OpenSSL (1.0.2g or later)

brew install openssl

You will need to have OpenSSL on your library path to run DDS-Security demos, you can do this by running:

export DYLD_LIBRARY_PATH=`brew --prefix openssl`/lib:$DYLD_LIBRARY_PATH

For convenience you can add this export to your bash_profile.

Install ROS2

Install from binaries

First install ROS2 from binaries following these instructions

Setup your environment:

source . ~/ros2_install/ros2-osx/setup.bash

In the rest of these instructions we assume that every terminal setup the environment as instructed above.

Install from source

For OpenSSL to be found when building code you'll need to define this environment variable:

export OPENSSL_ROOT_DIR=`brew --prefix openssl`

For convenience you can add this export to your bash_profile.

Install ROS2 from source following these instructions

Note: Fast-RTPS requires an additional CMake flag to build the security plugins so the colcon invocation needs to be modified to pass:

colcon build --symlink-install --cmake-args -DSECURITY=ON

Setup your environment:

source ~/ros2_ws/install/setup.bash

In the rest of these instructions we assume that every terminal setup the environment as instructed above.

Additional configuration for RTI Connext

To use DDS-Security with Connext you will need to procure an RTI Licence and install the security plugin. See this page for details on installing the security plugins.

Preparing the environment for the demo

Create a folder for the files required by this demo

We will now create a folder to store all the files necessary for this demo:

mkdir ~/sros2_demo

Generating a keystore, keys and certificates

Generate a keystore

cd ~/sros2_demo
ros2 security create_keystore demo_keys

Generate keys and certificates for the talker and listener nodes

ros2 security create_key demo_keys /talker
ros2 security create_key demo_keys /listener

Define the SROS2 environment variables

export ROS_SECURITY_ROOT_DIRECTORY=$(pwd)/demo_keys
export ROS_SECURITY_ENABLE=true
export ROS_SECURITY_STRATEGY=Enforce

These variables need to be defined in each terminal used for the demo. For convenience you can add it to your bash_profile.

Run the demo

ROS2 allows you to change DDS implementation at runtime. This demo can be run with fastrtps by setting:

export RMW_IMPLEMENTATION=rmw_fastrtps_cpp

And with Connext by setting:

export RMW_IMPLEMENTATION=rmw_connext_cpp

Note that secure communication between vendors is not supported.

Authentication and Encryption

Run the talker demo program:

ros2 run demo_nodes_cpp talker

In another terminal (after preparing the terminal as previously described), we will do the same thing with the listener program:

ros2 run demo_nodes_py listener

These nodes will be communicating using authentication and encryption! If you look at the packet contents on e.g. Wireshark, the messages will be encrypted.

Note: You can switch between the C++ and Python packages arbitrarily.

These nodes are able to communicate because we have created the appropriate keys and certificates for them. However, other nodes will not be able to communicate, e.g. the following invocation will fail to start a node with a name that is not associated with valid keys/certificates:

# This will fail because the node name does not have valid keys/certificates
ros2 run demo_nodes_cpp talker --ros-args -r __node:=not_talker

Access Control

The previous demo used authentication and encryption, but not access control, which means that any authenticated node would be able to publish and subscribe to any data stream (aka topic). To increase the level of security in the system, you can define strict limits, known as access control, which restrict what each node is able to do. For example, one node would be able to publish to a particular topic, and another node might be able to subscribe to that topic. To do this, we will use the sample policy file provided in examples/sample_policy.xml.

First, we will copy this sample policy file into our keystore:

svn checkout https://github.com/ros2/sros2/trunk/sros2/test/policies

And now we will use it to generate the XML permission files expected by the middleware:

ros2 security create_permission demo_keys /talker policies/sample_policy.xml
ros2 security create_permission demo_keys /listener policies/sample_policy.xml

These permission files will be stricter than the ones that were used in the previous demo: the nodes will only be allowed to publish or subscribe to the chatter topic (and some other topics used for parameters).

In one terminal (after preparing the terminal as previously described), run the talker demo program:

ros2 run demo_nodes_cpp talker

In another terminal (after preparing the terminal as previously described), we will do the same thing with the listener program:

ros2 run demo_nodes_py listener

At this point, your talker and listener nodes should be communicating securely, using explicit access control lists! Hooray!

The nodes will not be able to publish/subscribe to topics not listed in the policy. For example, the following attempt for the listener node to subscribe to a topic other than chatter will fail:

# This will fail because the node is not permitted to subscribe to topics other than chatter.
ros2 run demo_nodes_py listener --ros-args -r chatter:=not_chatter