PM-40727: feat: Add encryption layer for new KeystoreEncryptedSharedPreferences

[david-livefront]

🎟️ Tracking

PM-40727

📔 Objective

This PR creates a new KeystoreEncryptedSharedPreferences that utilizes the AndroidKeystore to encrypt the data stored. A followup PR will migrate the data to this new storage location.

Notable changes:

• The keys are stored as plaintext, whereas the old logic used AES_SIV for encryption. This encryption was not compliant with FedRamp requirements.
• We currently only support the storing of Strings (this is the only type we need at the moment).

[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: APPROVE

Reviewed the new KeystoreEncryptedSharedPreferences encryption layer, the supporting EncryptionManager/KeystoreManager (AES-256-GCM via the Android Keystore), their Hilt wiring, and the accompanying unit tests. The cryptographic construction is sound: a fresh random 12-byte IV is generated per encryption (no IV reuse), a 128-bit GCM tag is used consistently, key material stays in the AndroidKeyStore with aliases namespaced by application ID, and failures are surfaced through Result and logged via Timber. Test coverage is thorough across the encrypt/decrypt round trip, key generation/retrieval error paths, and the SharedPreferences contract.

Code Review Details

No new findings. The two open question threads on KeystoreEncryptedSharedPreferences.kt (write-path getOrThrow() throwing asymmetrically vs. the graceful read path, and getAll() value semantics) remain the appropriate place to continue that discussion and are not duplicated here.

[codecov]

Codecov Report

❌ Patch coverage is 90.19608% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.78%. Comparing base (f64a08d) to head (9dafd0d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...asource/disk/KeystoreEncryptedSharedPreferences.kt	77.77%	3 Missing and 3 partials ⚠️
...e/data/manager/encryption/EncryptionManagerImpl.kt	87.50%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7191      +/-   ##
==========================================
+ Coverage   86.20%   86.78%   +0.58%     
==========================================
  Files         884      873      -11     
  Lines       64657    64328     -329     
  Branches     9674     9684      +10     
==========================================
+ Hits        55737    55829      +92     
+ Misses       5456     5032     -424     
- Partials     3464     3467       +3     

Flag	Coverage Δ
app-data	17.71% <0.00%> (-0.03%)	⬇️
app-ui-auth-tools	18.75% <0.00%> (-0.04%)	⬇️
app-ui-platform	16.53% <0.00%> (-0.03%)	⬇️
app-ui-vault	27.33% <0.00%> (-0.05%)	⬇️
authenticator	6.14% <0.00%> (+0.03%)	⬆️
lib-core-network-bridge	4.15% <69.60%> (+0.13%)	⬆️
lib-data-ui	1.19% <20.58%> (+0.03%)	⬆️

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[andrebispo5]

Reviewed code and Claude findings, they were all addressed, looks good 👍

[david-livefront]

Thanks @andrebispo5