Trait SecureStorage 

pub trait SecureStorage {
    // Required methods
    fn store(&self, key: &str, value: &[u8]) -> Result<(), PersistenceError>;
    fn retrieve(&self, key: &str) -> Result<Option<Vec<u8>>, PersistenceError>;
    fn delete(&self, key: &str) -> Result<(), PersistenceError>;

    // Provided method
    fn exists(&self, key: &str) -> Result<bool, PersistenceError> { ... }
}

Platform-agnostic secure storage abstraction.

Implementations should use platform-specific secure storage:

• Android: EncryptedSharedPreferences / Keystore
• iOS: Keychain Services
• Linux: Encrypted file in XDG data directory
• ESP32: Encrypted NVS partition
• Windows: DPAPI

Required Methods

fn store(&self, key: &str, value: &[u8]) -> Result<(), PersistenceError>

Store bytes under the given key.

The implementation should encrypt the data at rest using platform-appropriate mechanisms.

fn retrieve(&self, key: &str) -> Result<Option<Vec<u8>>, PersistenceError>

Retrieve bytes for the given key.

Returns Ok(None) if the key doesn’t exist. Returns Err if the key exists but cannot be decrypted.

fn delete(&self, key: &str) -> Result<(), PersistenceError>

Delete the entry for the given key.

Returns Ok(()) even if the key didn’t exist.

Provided Methods

fn exists(&self, key: &str) -> Result<bool, PersistenceError>

Check if a key exists without retrieving its value.

Implementors

impl SecureStorage for MemoryStorage

Available on crate features std only.