def step3(self):
self._check_initialized()<EOL>session_key = binascii.unhexlify(self.client_session_key)<EOL>aes_key = hash_sha512('<STR_LIT>', session_key)[<NUM_LIT:0>:<NUM_LIT:16>]<EOL>tmp = bytearray(hash_sha512('<STR_LIT>', session_key)[<NUM_LIT:0>:<NUM_LIT:16>])<EOL>tmp[-<NUM_LIT:1>] = tmp[-<NUM_LIT:1>] + <NUM_LIT:1>  <EOL>aes_iv = bytes(tmp)<EOL>log_binary(_LOGGER, '<STR_LIT>', Key=aes_key, IV=aes_iv)<EOL>epk, tag = aes_encrypt(modes.GCM, aes_key, aes_iv, self._auth_public)<EOL>log_binary(_LOGGER, '<STR_LIT>', EPK=epk, Tag=tag)<EOL>return epk, tag<EOL>
Last authentication step.