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@thestinger thestinger released this 25 Feb 17:34
· 270 commits to main since this release

Full list of changes from the previous release (version 11). Notable changes:

  • detect severely out-of-date WebView (older than Chromium 89) and display an error page asking the user to update the WebView (will raise minimum version over time)
  • add separate release target for new Play Store release with as the app id (as opposed to the new standalone app.grapheneos.pdfviewer or the legacy org.grapheneos.pdfviewer) and a separate upload signing key for the app bundle

Simple Android PDF viewer based on pdf.js and content providers. The app doesn't require any permissions. The PDF stream is fed into the sandboxed WebView without giving it access to content or files. Content-Security-Policy is used to enforce that the JavaScript and styling properties within the WebView are entirely static content from the apk assets. It reuses the hardened Chromium rendering stack while only exposing a tiny subset of the attack surface compared to actual web content. The PDF rendering code itself is memory safe with dynamic code evaluation disabled, and even if an attacker did gain code execution by exploiting the underlying web rendering engine, they're within the Chromium renderer sandbox with no access to the network (unlike a browser), files, or other content.