TL;DR

This is a Proof of Concept (PoC) of a ACA-py controller for mobile application attestation. It has the following features:

Apple App Attestation - WIP
Android Play Integrity API
Apple Fraud Detection API
AppStore Receipt Checking (iOS <14.0)

Development

While this controller can be run as a controller for any ACA-py instance, it was developed using "Traction" as the front end. Any documentation or references should be considered in that context.

Prerequisites

VSCode
Docker
Traction >= 0.3.2
Suitable tool for exposing localhost to the internet:

How it Works

When run, this program will act as a "controller" to an ACA-py agent. It uses Flux to handle DidComm basic messages, and, when prompted, will use Traction to issue a basic demo Attestation Credential.

Running

Local Development

First, create a .env file in the root of your folder by copying env.sample to .env, populate the values with your own. For Android Attestation you will need a Google OAuth JSON key in /src configured for your app.

APPLE_ATTESTATION_ROOT_CA_URL="https://www.apple.com/certificateauthority/Apple_App_Attestation_Root_CA.pem"
TRACTION_BASE_URL="https://traction-tenant-proxy-dev.apps.silver.devops.gov.bc.ca"
TRACTION_WALLET_ID="b1d5b628-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
TRACTION_WALLET_KEY="286e7818-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
GOOGLE_AUTH_JSON_PATH="path_to_google_oauth_json_key_from_src.json"

You will also need to create a schema and credential definition id in your Traction instance and then add it to fixtures/offer.json, following the format.

For simplicity, this repo comes with a .devContainer to allow developers to get up-and-running quickly. Use VSCode to restart or start the container. Once the container is running, you can start the controller with the following command:

cd src
python controller.py

The output should look something like this:

vscode ➜ /work (main) $ python src/controller.py
 * Serving Flask app 'controller'
 * Debug mode: on
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 107-923-082

Flask will expose port 5000 and this is where you need to point whatever tool you have setup to expose localhost, for example, in the case of ngrok:

npx ngrok http 5000

Finally, whatever public endpoint is provided from, in this case ngrok needs to be provided to Traction as the controller endpoint. This can be done by going to Settings -> Tenant Profile and entering the URL in the WebHook URL field.

OpenShift Cluster

The general command to deploy this to an OpenShift cluster is:

helm template <RELEASE> ./devops/charts/controller
--set-string wallet_id=<WALLET_ID> \
--set-string wallet_key=<WALLET_KEY> \
--set-file google_oauth_key.json=<PATH_TO_GOOGLE_OAUTH_KEY>| \
oc apply -n <NAMESPACE> -f -

And example command to deploy to the e79518-dev namespace is:

helm template bcwallet ./devops/charts/controller
--set-string wallet_id=123-456-789 \
--set-string wallet_key=abc-def-ghi \
--set-file google_oauth_key.json=./google_oauth_key.json| \
oc apply -n e79518-dev -f -

The release name can be anything you want, but it must be unique to the namespace. When deploying to a shared namespace like e79518-dev, it is recommended use the a meaningful release name that will help reason about what the controller is doing.

Notes Below Here

https://developer.android.com/google/play/integrity/verdicts#device-integrity-field. You can then distinguish between MEETS_BASIC_INTEGRITY and MEETS_STRONG_INTEGRITY

Useful Packages

Here are some interesting packages that may be useful:

https://github.com/invertase/react-native-firebase/tree/main#readme https://www.npmjs.com/package/@react-native-firebase/app-check npm i -S @react-native-firebase/app-check

https://github.com/kedros-as/react-native-google-play-integrity https://www.npmjs.com/package/react-native-google-play-integrity npm i -S react-native-google-play-integrity

https://github.com/bpofficial/expo-attestation#readme https://www.npmjs.com/package/expo-attestation npm i -S expo-attestation

Handy Test Commands

jq --arg content "$(cat fixtures/request_issuance.json | base64)" --arg name "jason" '.content |= $content | .name |= $name' fixtures/basic_message.json

jq --arg content "$(cat fixtures/request_issuance.json | base64)" '.content |= $content' fixtures/basic_message.json|curl -v -X POST -H "Content-Type: application/json" -d @- http://localhost:5000/topic/basicmessages/

jq -s '.[0] * .[1]' source.json target.json

jq --arg content "$(jq -s '.[0] * .[1]' fixtures/chalange_response.json attestation.json | base64)" '.content |= $content' fixtures/basic_message.json| curl -v -X POST -H "Content-Type: application/json" -d @- http://localhost:5000/topic/basicmessages/

Apple Verifications Steps

After successfully completing these steps, you can trust the attestation object.

Android Verification Steps

Get Integrity Verdict from Google's server via their python client
Verify the package info matches our app
Verify the device integrity fields
Verify the app integrity fields (left commented out while in development)
Verify the nonce in the verdict payload matches the nonce the controller sent to the device

fullboar/mobile-attestation-vc-controller