CBC/Radio-Canada C2PA Dash Demo

requirements

• docker
• python3
• pyinstaller
• c2patool
• aws key configuration

Run

docker compose up

http://localhost:81/

instructions

1. Certificates

a. Use a self-signed certificate

Nothing to do, we'll clone a test one with c2patool

b. Build a signer

#Update key information in the signer
pyinstaller --onefile signer.py

#test the signer
echo "votre_message" | ./dist/test

# copy your ps256.pub file in asset/sample/

2. Encode the mp4 into a Dash fmp4

cd asset
cp -r ../dist .
wget https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/360/Big_Buck_Bunny_360_10s_1MB.mp4
MP4Box Big_Buck_Bunny_360_10s_1MB.mp4 -dash 4000 -frag 40000 -rap -profile live -out c2pa_dash_demo/output.mpd  # fragment are smaller than 4096 for the kms signer

3 Sign the fmp4 either with the self signed certificate or the AWS KMS service

wget https://github.com/contentauth/c2patool/releases/download/v0.9.12/c2patool-v0.9.12-universal-apple-darwin.zip
unzip c2patool-v0.9.12-universal-apple-darwin.zip -d c2pa_cli
cp c2pa_cli/c2patool/c2patool .

with the signer

Go into sample/test.json and replace sign_cert with your own public key: "sign_cert": "!!! REPLACE BY YOUR OWN PUBLIC KEY !!!",

c2patool -m sample/test.json --signer-path dist/test -o dash-signed/ "c2pa_dash_demo/Big_Buck_Bunny_360_10s_1MB_dashinit.mp4" fragment --fragments_glob "Big_Buck_Bunny_360_10s_1MB_dash*[0-9].m4s"

Without the signer

c2patool -m c2pa_cli/c2patool/sample/test.json -o c2pa_dash_demo_signed/ "c2pa_dash_demo/Big_Buck_Bunny_360_10s_1MB_dashinit.mp4" fragment --fragments_glob "Big_Buck_Bunny_360_10s_1MB_dash*[0-9].m4s"

4 Copy the playlist back into the signed asset

cp c2pa_dash_demo/output.mpd c2pa_dash_demo_signed/c2pa_dash_demo

5 Copy the asset in the website

cp -r c2pa_dash_demo_signed/c2pa_dash_demo ../html/

Credits

• https://dashif.org/events/special-sessions/ [June 7, 2024: DASH-IF Special Session: Content Authenticity and Provenance in DASH]
• https://github.com/contentauth/c2patool/blob/main/src/callback_signer.rs
• https://github.com/aws-solutions-library-samples/guidance-for-media-provenance-with-c2pa-on-aws