Struct BroadcastKey 

pub struct BroadcastKey(/* private fields */);

A 32-byte ChaCha20-Poly1305 key for decrypting encrypted broadcast notifications. Zeroized on drop; its Debug is redacted.

Implementations

impl BroadcastKey

pub fn derive(ikm: &[u8], salt: &[u8]) -> Result<Self>

Derive the broadcast key via HKDF-SHA512, info "Broadcast-Encryption-Key". ikm is the Pair-Verify shared secret; salt the controller LTPK.

Errors

CryptoError on an HKDF length error (never for 32-byte output).

pub fn from_bytes(key: [u8; 32]) -> Self

Wrap raw key bytes (restored from persisted broadcast state).

pub fn as_bytes(&self) -> &[u8; 32]

The raw key bytes, for caller persistence. Handle as a secret.

pub fn seal( &self, gsn: u16, plaintext: &[u8], advertising_id: &[u8; 6], ) -> Vec<u8>

Encrypt plaintext into a broadcast payload ciphertext || tag[:4] for gsn, binding the 6-byte advertising_id as AAD. Uses the HAP 4-byte partial Poly1305 tag — the symmetric counterpart of BroadcastKey::open.

The returned Vec<u8> is ciphertext || 4-byte-tag, ready to append to a 0x11 advertisement after the advertising id. Primarily useful for tests and tooling (an accessory seals; a controller opens).

pub fn open( &self, gsn: u16, combined_text: &[u8], advertising_id: &[u8; 6], ) -> Result<Vec<u8>>

Decrypt one encrypted broadcast payload combined_text (= ciphertext || tag[:4]) for gsn, binding the 6-byte advertising_id as AAD. Uses the HAP 4-byte partial Poly1305 tag.

Errors

CryptoError::Aead if the partial tag does not match (wrong key/gsn/aad or tampered payload) or the input is too short.

Trait Implementations

impl Clone for BroadcastKey

fn clone(&self) -> BroadcastKey

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BroadcastKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for BroadcastKey

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Zeroize for BroadcastKey

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.