PM-40154: feat: Migrate user data to KeystoreEncryptedSharedPreferences

[david-livefront]

🎟️ Tracking

PM-40154

📔 Objective

This PR creates a new KeystoreEncryptedSharedPreferences that utilizes the AndroidKeystore to encrypt the data stored.

Notable changes:

• This migrates us away from EncryptedSharedPreferences which is deprecated and is not FIPS compliant.
• The keys are not stored as plaintext.
• We currently only support the storing of Strings (this is the only type we need at the moment).

[codecov]

Codecov Report

❌ Patch coverage is 96.36364% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.68%. Comparing base (274594c) to head (5427582).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
...en/data/datasource/disk/BaseEncryptedDiskSource.kt	94.11%	0 Missing and 1 partial ⚠️
...anager/flightrecorder/FlightRecorderManagerImpl.kt	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7158      +/-   ##
==========================================
- Coverage   86.11%   85.68%   -0.43%     
==========================================
  Files         894     1052     +158     
  Lines       65201    68046    +2845     
  Branches     9756     9877     +121     
==========================================
+ Hits        56147    58307    +2160     
- Misses       5559     6210     +651     
- Partials     3495     3529      +34     

Flag	Coverage Δ
app-data	17.98% <76.36%> (+0.17%)	⬆️
app-ui-auth-tools	18.94% <0.00%> (+0.28%)	⬆️
app-ui-platform	16.99% <0.00%> (+0.52%)	⬆️
app-ui-vault	27.92% <0.00%> (+0.52%)	⬆️
authenticator	6.12% <45.45%> (+0.05%)	⬆️
lib-core-network-bridge	4.12% <0.00%> (+<0.01%)	⬆️
lib-data-ui	1.20% <3.63%> (-0.01%)	⬇️

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[quexten]

If we had a tech breakdown beforehand, I'd recommend implementing this in the SDK based on our modern encryption primitives instead. Given the stage, I'll comment the minimum to make this reasonably secure. I recommend dropping the separate MAC key, and switching from CBC to GCM. Currently, the API is very easy to misuse, and you generally do not want to expose separate authentication and encryption (without authentication) APIs.

Outdated

[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: REQUEST CHANGES

Reviewed the migration of encrypted SharedPreferences data from the deprecated EncryptedSharedPreferences to the new KeystoreEncryptedSharedPreferences, covering BaseEncryptedDiskSource.migrateKeyByPrefix, the three disk sources that consume it (app AuthDiskSourceImpl, authenticator AuthDiskSourceImpl, CookieDiskSourceImpl), the new DiskSourceMigrationLogger, and the FlightRecorderManager.isLoggingReadyFlow addition. The migration key lists for the authenticator auth disk source and the cookie disk source cover every prefix those classes read, and the removal of the bwSecureStorage: prefix is consistently reflected in the updated tests. One gap was found in the app's AuthDiskSourceImpl, where an encrypted key read during init is not covered by the new migration and is read before the migration runs.

Code Review Details

• ❌ : profileAccountKeys is never migrated and migrateAccountKeys() runs before migrateToKeystoreEncryption(), silently downgrading V2 account cryptographic state for users upgrading from ≤ v2026.5.x
  • app/src/main/kotlin/com/x8bit/bitwarden/data/auth/datasource/disk/AuthDiskSourceImpl.kt:139

[claude]

❌ CRITICAL: profileAccountKeys is never migrated, so migrateAccountKeys() silently reads null for users upgrading from ≤ v2026.5.x.

Details and fix

Two problems combine here:

1. migrateToKeystoreEncryption() runs last in init, but migrateAccountKeys() (line 137) already calls getEncryptedString(key = accountKeysKey). getEncryptedString now reads only from keystoreEncryptedPreferences, which is still empty at that point.
2. PROFILE_ACCOUNT_KEYS_KEY is not in the migrateToKeystoreEncryption() prefix list at all, so bwSecureStorage:profileAccountKeys_<userId> is never moved.

Before #7030 (shipped in v2026.6.0), account keys were written via putEncryptedString(PROFILE_ACCOUNT_KEYS_KEY…), so any user who last ran v2026.5.x or earlier still has that entry in the legacy store. For those users accountKeys resolves to null, and migrateAccountKeys falls through to getString(privateKeyKey). AccountKeysJson?.toAccountCryptographicState then returns WrappedAccountCryptographicState.V1 because signingKey, securityState, and signedPublicKey are all null — a V2 account is silently downgraded to V1.

Side effect: putEncryptedString(key = accountKeysKey, value = null) now clears the new store (a no-op), so the legacy bwSecureStorage:profileAccountKeys_* entry is left behind in the deprecated EncryptedSharedPreferences indefinitely. That also keeps encryptedPreferences.all.size > 2, suppressing the new DiskSourceMigrationLogger signal.

Suggested fix — run the keystore migration right after the legacy secure storage migration (which populates encryptedSharedPreferences) but before the other migrations, and include the profile account keys prefix:

init {
    legacySecureStorageMigrator.migrateIfNecessary()

    // Migrate to the Keystore Encrypted SharedPreferences before any encrypted values are read.
    migrateToKeystoreEncryption()

    migrateAccountTokens()
    removeLegacyUserKeys()
    migrateAccountKeys()
}

and in migrateToKeystoreEncryption():

isMigrated = migrateKeyByPrefix(keyPrefix = PROFILE_ACCOUNT_KEYS_KEY) || isMigrated

A regression test seeding bwSecureStorage:profileAccountKeys_<userId> and asserting a V2 WrappedAccountCryptographicState survives the upgrade would lock this down.