From a whole-repo security review (no critical/high issues; TLS cert and
hostname validation were already intact):
- Don't offer the plaintext "None" transport in manual account setup; it
would send credentials in the clear. The enum value stays only for local
test servers.
- Relabel the advanced toggle "Allow insecure STARTTLS fallback" with a
warning subtitle: it relaxes (does not enable) STARTTLS and permits a
plaintext downgrade when on. Default stays off/secure.
- Set mail.<proto>.ssl.checkserveridentity=true explicitly on IMAP/SMTP as
insurance over the (already-true) Angus default.
- Add a Content-Security-Policy meta to the reader WebView (JavaScript is
already disabled).
- Strip Log.d/Log.v in release builds and drop the account address from the
IDLE log; mark new-mail notifications VISIBILITY_PRIVATE.
Add opt-in at-rest encryption of the Room cache (Settings -> "Encrypt local
cache", off by default) using SQLCipher. The DB passphrase is a random key
sealed by the existing Keystore crypto and kept in a separate DataStore.
DatabaseEncryption performs a self-healing, atomic plaintext<->encrypted
migration at startup that preserves PRAGMA user_version, so toggling applies
on next launch without data loss.
Verified end-to-end on an API 37 emulator (DatabaseEncryptionTest round-trip,
7 instrumented tests) plus 12 unit tests and a release R8 build.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
JMR-devandClaude Opus 4.8
96c9f71a26