Client-side viewer to open PDF documents embedded in P7M (CAdES) files directly in the browser. Modern UI, automatic light/dark theme and language detection, drag & drop, stacked page rendering, selectable text, and local download. 100% front-end, no backend or uploads.

• Open P7M-signed PDFs fully client-side (privacy-first)
• Modern, responsive UI with rounded components
• Auto theme (light/dark) via prefers-color-scheme
• Auto language: Italian if browser is IT, English otherwise
• Drag & drop or green "Open document" button
• Stacked page viewer (A4 portrait/landscape) with smooth scrolling
• Selectable/copyable text via PDF.js text layer
• Download extracted PDF and "Reset" to restart
• No backend, no file uploads, no installation

1. The app reads the P7M file as raw bytes in the browser.
2. It applies a pragmatic "file carving" approach to extract PDFs by:
   • Removing a set of known ASN.1 byte sequences commonly seen around CAdES content.
   • Locating the first "%PDF" header and the last "%%EOF" marker, and slicing the in-between segment.
3. The extracted PDF is rendered with PDF.js. Pages are stacked vertically and a text layer is placed above the canvas to enable natural text selection.
4. You can download the extracted PDF or reset the UI to load another file.

Note: This is an empirical extraction method aimed specifically at PDFs inside P7M. It does not verify the digital signature.

• 100% front-end: processing happens in your browser.
• No files are uploaded to any server.
• No signature validation is performed; only extraction and viewing of the embedded PDF.

1. Download or clone this repository.
2. Make sure the following files are present in the same folder:
   • index.html
   • styles.css
   • app.js
   • pdf.min.js
   • pdf.worker.min.js
   • (optional) pkijs-asn1js.bundle.js for future local signature/ASN.1 experiments
3. Open index.html in a modern browser.

If your browser blocks local worker files, serve the folder with a tiny static server, for example:

Then open http://localhost:8000

• From the landing screen:
  • Click the green "Open document" button and select a .p7m file, or
  • Drag and drop a .p7m file into the blue drop zone.
• After loading:
  • The landing controls disappear (only the title remains), the PDF pages are shown stacked.
  • Use "Download document" to save the extracted PDF.
  • Use "Reset" to go back and open a different file.

Language and theme are applied automatically:

• Language: Italian if your browser locale starts with "it", English otherwise.
• Theme: respects the system light/dark preference.

• Chrome, Firefox, Edge, Safari -- latest versions recommended
• Desktop and mobile supported; very large PDFs may be slower on mobile devices

• Works for P7M files that contain a PDF. Other embedded types are not supported.
• No digital signature validation, revocation checks, or trust verification.
• The byte-sequence cleanup and carving approach is pragmatic and may not work for every P7M variant or producer.
• Rendering and text selection rely on PDF.js; quality may vary depending on the PDF content.

• PDF.js