Download
P7S Universal Viewer v2.0.0 is a free, MIT-licensed Windows 10/11 x64 utility by ALMARFELD. Open CMS/PKCS#7 containers, inspect each signer, verify signature integrity and extract embedded content without changing its bytes. Detached signatures require the exact original file; they cannot reconstruct a missing document.
Files are processed locally, without accounts, uploads or telemetry. Certificate trust and validity dates are separate from integrity. Revocation and trusted timestamp verification are not performed. Microsoft Edge WebView2 Runtime is optional for PDF preview only. Windows binaries are not Authenticode signed.
Current product, screenshots and download information:
https://almarfeld.com/software/p7s-universal-viewer/
Official v2.0.0 installer and portable ZIP:
https://github.com/AlinTibi/p7s-universal-viewer/releases/tag/v2.0.0
The SourceForge v1.0.0 files are historical; use the current official release above.
Features
- Open attached CMS/PKCS#7 P7S and P7M containers on Windows
- Verify each signature separately from certificate trust and dates
- Extract original embedded content without changing its bytes
- Verify detached signatures using the exact original file
- Local processing; free and open source under MIT
Project Samples
