modbender QR Password — Air-Gapped Credential Bridge
Bidirectional credential transfer using QR codes as an optical channel. No secret touches a network.
Security Rules (MANDATORY)
- Never log credentials to chat history or memory files
- Redact passwords from all conversation output — show
****instead - Auto-clear canvas display after 30 seconds using timed canvas hide
- QR images are ephemeral — delete after use with
rm - Never store decoded credentials in any file
Mode A: Vault → QR (Outbound)
Generate a QR code from a credential for an air-gapped device to scan.
echo '{"username":"USER","password":"PASS","domain":"DOMAIN"}' | \
python3 skills/qr-password/scripts/generate-qr.py /tmp/qr-out.png
Then display via canvas and auto-clear:
canvas present /tmp/qr-out.png
# Wait 30s
canvas hide
rm /tmp/qr-out.png
When reporting to user, say "QR displayed" — never echo the password.
Mode B: Camera → Credential (Inbound)
Read a QR code from a camera image to extract credentials.
- Capture image:
nodes camera_snap(or accept user-provided image) - Decode:
python3 skills/qr-password/scripts/read-qr.py /path/to/image.png
- Output is JSON:
{"username":"...","password":"...","domain":"..."} - Use the credential (fill, copy, deliver) — never echo password to chat
- Delete the image:
rm /path/to/image.png
Offline QR Generator
For air-gapped devices, provide assets/qr-generator.html — a standalone offline HTML page that generates QR codes locally in-browser. No network required.
Dependencies
Python 3 with: qrcode, Pillow, opencv-python-headless
Install: python3 -m pip install --user qrcode Pillow opencv-python-headless