bench get-app https://github.com/Tusharp21/scan_me

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Scan Me

A Frappe app that turns any allowlisted document into a verifiable, signable PDF — with a Chromium-based PDF pipeline, QR-backed verification, optional content hashing, and PAdES digital signatures recognised by Adobe Acrobat.

Features

• Verified QR per signed document (UUIDv4 + optional SHA-256 content hash + signatory metadata).
• Public verify page at /verify_document/ with a camera scanner that returns valid / tampered / invalid for any QR.
• Chromium PDF pipeline (Playwright) with full modern CSS support.
• Live-preview print dialog with iframe that regenerates on every option change.
• Multi-copy PDF (1–5 copies) with ORIGINAL / DUPLICATE / custom labels.
• Per-page header/footer modes: all pages / first only / last only / first+last / none.
• Dialog-driven QR insertion in any of four corners.
• Acrobat-style signature block rendered as an Acrobat Sign-style card.
• PAdES digital signatures via PyHanko, Adobe-compatible.
• Lockable audit trail with optional absolute lock on Verified QR records.
• Jinja helpers: qr, barcode, qr_link, qr_img, qr_link_img, verify_qr, verify_qr_img.
• Bundled Sales Invoice Scan Me print format.

Installation

bench get-app scan_me
bench install-app scan_me

Playwright's Chromium browser is downloaded automatically by the after_install hook so PDF generation works immediately.

Fallback — manual Chromium install

If the auto-download fails, run this once on the server:

./env/bin/python -m playwright install chromium

Python dependencies

• qrcode
• python-barcode
• playwright
• pypdf
• pyHanko
• cryptography

All install automatically via bench install-app.

Configuration

Open Scan Me Settings in the desk:

1. Under Doctype, add the DocTypes you want to expose for QR signing. Tick enable for each; tick signature_required if users must draw a signature before generating the QR.
2. Under Verification & Signing, configure:
   • Allow Multiple Signers — N-party signing.
   • Embed Content Hash in QR — tamper detection on doc edits.
   • Lock Verified QR After Insert — absolute lock, no override.
   • Use Stored User Signature Only — reads from a User custom field named user_signature / signature / signature_image.
   • Apply Cryptographic PDF Signature (PAdES) — run every generated PDF through PyHanko.
3. Under Print Dialog Features, toggle which sections of the print dialog your users see.

PAdES configuration

The first time PAdES signing runs, Scan Me auto-generates a 5-year self-signed PKCS#12 at sites//private/files/scan_me/signing.pfx and stores its password in site_config.json under scan_me_signing_password.

To upgrade to a CA-issued certificate:

1. Obtain a PKCS#12 bundle from a trusted CA.
2. Replace sites//private/files/scan_me/signing.pfx with the new file.
3. Update scan_me_signing_password in site_config.json to the bundle's password.

Usage

Sign a document

1. Open a doc of an allowlisted DocType.
2. Click Generate Verified QR in the form's menu.
3. Draw a signature if prompted. A Verified QR record is created.

Generate a PDF

1. Menu → Print → select a print format.
2. Click the Generate PDF button in the toolbar.
3. Configure copies, header/footer, QR, signature block, PAdES signing.
4. Download PDF.

Verify a QR

• Open the verify page on a phone or laptop with a camera.
• Scan the QR on the printed/PDF document.
• Page shows valid (green), tampered (red, hash mismatch), or invalid (UUID unknown).

License

MIT — see license.txt.