get to prod tasks

tasks/android-production/07-encrypted-storage.md

@@ -0,0 +1,80 @@
+# 07. Encrypted SharedPreferences & DataStore Audit
+
+meta:
+  id: android-production-07
+  feature: android-production
+  priority: P1
+  depends_on: []
+  tags: [security, data-protection, production]
+
+objective:
+- Audit and secure all local data storage using encrypted SharedPreferences and DataStore
+
+deliverables:
+- EncryptedSharedPreferences for sensitive data
+- DataStore for preferences
+- Secure data deletion
+- Storage audit report
+
+steps:
+1. Audit current storage:
+   - Review all SharedPreferences usage
+   - Review DataStore usage
+   - Review CacheManager.kt
+   - Identify all sensitive data stored locally
+2. Implement encrypted preferences:
+   - Use EncryptedSharedPreferences from androidx.security
+   - Store auth tokens, refresh tokens
+   - Store biometric preference
+   - Store user profile data
+3. Configure DataStore:
+   - Use DataStore for non-sensitive preferences
+   - Theme, language, notification settings
+   - Migrate from SharedPreferences if needed
+4. Secure CacheManager:
+   - Ensure no sensitive data in unencrypted cache
+   - Encrypt cached API responses containing PII
+   - Set cache size limits
+   - Implement secure eviction
+5. Add secure deletion:
+   - Overwrite sensitive data before removal
+   - Clear all secure storage on logout
+   - Handle account deletion (GDPR)
+6. Add backup exclusion:
+   - Exclude encrypted preferences from cloud backup
+   - Mark sensitive files with android:allowBackup="false"
+   - Document backup strategy
+7. Test storage security:
+   - Verify data encrypted at rest
+   - Verify no plaintext sensitive data in files
+   - Test backup/restore behavior
+
+tests:
+- Unit: Test encrypted storage read/write
+- Security: Verify no plaintext tokens in files
+- Integration: Test logout clears all data
+
+acceptance_criteria:
+- All sensitive data in EncryptedSharedPreferences
+- Auth tokens encrypted at rest
+- Refresh tokens encrypted at rest
+- Non-sensitive preferences in DataStore
+- No sensitive data in unencrypted cache
+- Secure deletion overwriting data
+- Sensitive storage excluded from backup
+- Logout clears all auth data
+- Account deletion removes all local data
+- No plaintext sensitive data discoverable in app files
+
+validation:
+- Inspect app files → no plaintext tokens
+- Check EncryptedSharedPreferences → data encrypted
+- Logout → all auth data cleared
+- Backup app → sensitive data not included
+- Account deletion → all data removed
+
+notes:
+- EncryptedSharedPreferences uses AES-256 encryption
+- Master key stored in Android Keystore
+- DataStore is modern replacement for SharedPreferences
+- Consider using SQLCipher for database encryption if using Room