Noise IoT Project

Authors

• Jaime Galán Martínez
• Mario Vuksa
• Víctor Aranda López

Noise protocol summary

Noise is a protocol framework for 2 party secure-channel protocols. It provides a simple pattern language and naming scheme for 2-party DH-based cryptographic handshakes, covering the different possibilities for client and/or server authentication, post/pre-specified peers, identity-hiding and 0-RTT encryption. These patterns are easily compiled into linear sequences of cryptographic operations using your favorite ECDH, hash, and cipher functions.

Used by Wireguard and WhatsAPP

Crypto Background

Authenticated key exchange - AKE

Sequence of messages exchanged by 2 parties to authenticate each other and establish a shared secret key. Properties: - forward secrecy - mutual or 1-way authentication - pre-knowledge of identities, identity-hiding - crypto used: DH, certs, signatures

Secure Channel Protocol

All have same structure:

• Handshake phase: Authenticates and establishes shared secret
  • Negotiation (determines type of AKE, parameters of AKE, type of encryption) -> can have fallback options
  • AKE
• Transport phase: Uses shared secret keys to ecrypt data

Noise Framework

Designed to build a protocol for a specific use case, so you want to think in advance which AKE to use and which cryptography to get, to remove complexity. This is very unlike TLS for example where the negotiation happens over which cryptography and key exchange is accepted. This because we want to remove branching, improve testability through:

• runtime decisions are made only when we select the noise protocol
• this selection encupsulates everything in a linear sequence of code(AKE+transport encryption)

Noise protocol brakedown:

• Negotiation layer - 1 transition, if first selection fails go to other, no more than 2 posibilities
• Handshake Pattern(abstract AKE) instantiated by:
  • Public key crypto
  • Symmetric crypto
• Encoding layer: ex. sending over TCP so add length fields, HTTP encoding etc.

Noise protocol are defined by their names.

Python modules

Noise Protocol Framework - Python 3 implementation

We used the following Noise Protocol implementation for our project: https://github.com/plizonczyk/noiseprotocol

noise_prot_interface.py

Python file that has two main classes: NoiseProtocolServer and NoiseProtocolCLient.

mqtt_broker2.py

Opens socket and waits for connection from client, when client connects sends message.

mqtt_cli2.py

When establishes connection to server receives message. It publishes messages about the CPU's temperature to the server.

The communication can be observed on any platform with Wireshark looking at the loopback interface.

Setup

Create python virtual environment with (depending on your system you might have to change python3 to python and pip3 to pip):

    python3 -m venv venv
    source venv/bin/activate
    pip3 install -r requirements.txt

Run server in one terminal and the client in the other. For doing that run the following scripts:

• ./run_broker.sh (python3 mqtt_broker2.py -u iot -p iot)
• ./run_cli.sh (python3 mqtt_cli2.py -u iot -p iot -t cpu_temp -c pub -n 2000)

Read/Watch list

• [1] https://www.youtube.com/watch?v=C-kWVb81tCc
• [2] https://noiseprotocol.org/noise.html
• [3] https://noiseprotocol.org/specs/noisesocket.html