Trait LeafStore 

pub trait LeafStore: Send + Sync {
    // Required methods
    fn store(
        &self,
        key_type: &str,
        key_id: &str,
        data: &[u8],
    ) -> Result<(), StoreError>;
    fn load(
        &self,
        key_type: &str,
        key_id: &str,
    ) -> Result<Option<Vec<u8>>, StoreError>;
    fn delete(&self, key_type: &str, key_id: &str) -> Result<(), StoreError>;
}

Durable storage for a leaf node’s secret material and MLS state.

The shape mirrors MlsStorage in offline-protocol-mls, which is the same seam on the phone: a two-part (key_type, key_id) key, &self methods so one store can be shared by the several places that write through it, and per-entry atomicity. A device implements it over the part’s secure key storage, its flash filesystem, or an EEPROM.

Errors

Returning an error is always safe. It aborts the operation before anything is emitted, which is the whole point of the seam.

Required Methods

fn store( &self, key_type: &str, key_id: &str, data: &[u8], ) -> Result<(), StoreError>

Writes data, replacing any previous value for this key.

Must be durable and atomic per entry: after Ok, a power cut leaves either the new value or the old one, never a torn record, and a subsequent LeafStore::load returns the new value.

fn load( &self, key_type: &str, key_id: &str, ) -> Result<Option<Vec<u8>>, StoreError>

Reads a value, or None if this key was never written.

fn delete(&self, key_type: &str, key_id: &str) -> Result<(), StoreError>

Removes a value. Removing a key that is not there is not an error.

Every value this crate stores is secret, so an implementation should erase rather than unlink.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl LeafStore for MemoryStore