Initializes the AEGIS-256x2 MAC state with the provided key and nonce.
The key (must be aegis256x2_KEYBYTES long).
The nonce (must be aegis256x2_NPUBBYTES long).
AssertError if key or nonce lengths are invalid.
See Implementation
Initializes the AEGIS-256x2 MAC state with the provided key and nonce.