Creates a session from a device address and its two 16-byte session keys.
nwkSKey authenticates frames and appSKey encrypts payloads.
Verifies a received frame, then decrypts it.
fcnt is the full 32-bit counter expected for this frame; its low 16 bits
must match the counter the frame carries.
Encodes a downlink, encrypting the payload and appending the MIC.
Optionaloptions: LorawanOptions | nullEncodes an uplink, encrypting the payload and appending the MIC.
Optionaloptions: LorawanOptions | null
An activated LoRaWAN session: a device address and its two session keys.