Adds the Double Ratchet (Signal's design) on top of the existing ECDH session
keys, so message protection no longer rests on one set of keys lasting the whole
conversation. Every message gets its own key, derived through a one-way function
and discarded after use, and each change of direction introduces a fresh ECDH
key pair that re-keys the session root.
The ratchet needed no handshake change: both peers already hold each other's
authenticated ECDH public key, and the safety code compared during verification
covers exactly those keys. Its root is derived from the existing shared secret
through its own branch of the key schedule.
Support is negotiated in the invitation and response and used only when both
sides have it; a peer on an earlier release falls back to per-session keys. The
security panel reports which of the two is actually in force.
Out-of-order delivery is supported within fixed bounds (512 skipped keys per
chain, 1024 retained, five-minute expiry), and inbound frames are authenticated
before any ratchet state is committed, so a malformed frame cannot desynchronise
a live session.
Also in this release:
- Verification is enforced as a gate, not a label: control frames (reconnection
signalling, call setup, message deletion, delivery receipts) are acted on only
after both peers have compared the safety code, and verified state is set in a
single guarded place.
- Chat content reaches the interface through one authenticated path; an older,
weaker inbound path was retired.
- The security panel measures what it displays — several checks previously
returned a fixed result and now exercise the subsystem they describe.
- Invitation data is no longer kept in local storage, and entries left by earlier
versions are cleared on first launch.
- View-once and disappearing messages no longer place their text in system
notifications.
- Shared-secret buffers are overwritten once derivation completes; scanned QR
codes are decompressed with a size limit; voice notes are validated against
audio type and size budgets before skipping the consent prompt; the master
password is collected by the app rather than a browser dialog.
- Connection setup no longer fails on networks where STUN/TURN are unreachable:
it proceeds as soon as usable candidates exist and only waits while there are
none.
Test suite grows from 27 to 41 files, covering forward secrecy, post-compromise
re-keying, out-of-order delivery across ratchet steps, the skipped-key bounds,
tamper resistance, negotiation fallback, and byte-level key-derivation
compatibility with 5.6.0.
- Replaced original JSON with minimized binary format (gzip + base64).
- Adjusted rendering and QR code generation for compatibility.
- Reduced payload size for improved efficiency.
- Updated connection flow between users via QR codes
- Added manual switching option in QR code generator
- Increased number of QR codes for better readability
- Removed session creation and Lightning payment logic
- Refactored security system:
* no more restrictions
* all systems enabled on session creation
- Improved QR code exchange for mobile devices
Replace CDN React/ReactDOM/Babel with local libs; remove Babel and inline scripts
Build Tailwind locally, add safelist; switch to assets/tailwind.css
Self-host Font Awesome and Inter (CSS + woff2); remove external font CDNs
Implement strict CSP (no unsafe-inline/eval; scripts/styles/fonts from self)
Extract inline handlers; move PWA scripts to external files
Add local QR code generation (qrcode lib) and remove api.qrserver.com
Improve SessionTypeSelector visual selection (highlighted background and ring)
Keep PWA working with service worker and offline assets
Refs: CSP hardening, offline-first, no external dependencies
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