The viewer compiled for Win64 but died on first use: AesGcmDecrypt existed
only as JNI, so the desktop build downloaded 27 KB and then refused it.
Windows has the same primitive in bcrypt.dll - no DLL to ship, no OpenSSL,
and BCryptDeriveKeyPBKDF2 takes bytes, so none of the char[] encoding doubt
that keeps the Pascal loop around on Android.
This exists so the client can be exercised on the desktop; deploying an APK
to watch a list redraw is a slow way to build a UI.
selftest.dpr replaces the crypto-vector button the viewer dropped: same
known-answer vector, console, exit code = failures. Measured here - Pascal
1670 ms, CNG 528 ms, identical keys on the non-ASCII password.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Replaces the crypto test bench with the three screens the client actually
needs. PMA.Vault holds the decrypted snapshot and answers the search;
mainApk builds unlock/list/detail in code rather than three .fmx files.
Two safety rules live in the UI because nowhere else can hold them: the
plaintext is dropped when the app backgrounds (screen hidden on
WillBecomeInactive, which precedes the recents-preview capture), and the
clipboard is cleared after 45 s only if it still holds what we put there.
The search deliberately ignores the password field.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
GET in 80 ms, decryption in 3893 ms, entries and trash counted, second call answers 304. try-open.js opens a container with Node so a failure can be attributed: a GCM tag that does not verify means wrong password OR altered file, and the app cannot tell which.
Measured on device: Android derives the same key as WebCrypto on a non-ASCII password, so PBEKeySpec does encode as UTF-8 - the doubt that justified the Pascal implementation was unfounded. It is barely faster though, 3869 ms against 4139 ms: PBKDF2 gets no hardware acceleration.
So 4 seconds per container is incompressible, and the iteration count belongs to the desktop format. The answer is not to speed up the derivation but to stop repeating it: derive once per snapshot, then keep the vault locally under an Android Keystore key. Written up in android-client/README.md.
r-zakarya