def _m5_setup(self, pairing_data):
session_key = hkdf_expand(
"Pair-Setup-Encrypt-Salt",
"Pair-Setup-Encrypt-Info",
binascii.unhexlify(self.session.key),
)
acc_device_x = hkdf_expand(
"Pair-Setup-Accessory-Sign-Salt",
"Pair-Setup-Accessory-Sign-Info",
binascii.unhexlify(self.session.key),
)
chacha = chacha20.Chacha20Cipher(session_key, session_key)
decrypted_tlv_bytes = chacha.decrypt(
pairing_data[TlvValue.EncryptedData], nounce="PS-Msg05".encode())
_LOGGER.debug("MSG5 EncryptedData=%s", read_tlv(decrypted_tlv_bytes))
other = {
"altIRK": b"-\x54\xe0\x7a\x88*en\x11\xab\x82v-'%\xc5",
"accountID": "DC6A7CB6-CA1A-4BF4-880D-A61B717814DB",
"model": "AppleTV6,2",
"wifiMAC": b"@\xff\xa1\x8f\xa1\xb9",
"name": "Living Room",
"mac": b"@\xc4\xff\x8f\xb1\x99",
}
device_info = acc_device_x + self.unique_id + self.keys.auth_pub
signature = self.keys.sign.sign(device_info)
tlv = {
TlvValue.Identifier: self.unique_id,
TlvValue.PublicKey: self.keys.auth_pub,
TlvValue.Signature: signature,
17: opack.pack(other),
}
tlv = write_tlv(tlv)
chacha = chacha20.Chacha20Cipher(session_key, session_key)
encrypted = chacha.encrypt(tlv, nounce="PS-Msg06".encode())
tlv = write_tlv({
TlvValue.SeqNo: b"\x06",
TlvValue.EncryptedData: encrypted
})
self.send_to_client(FrameType.PS_Next, {"_pd": tlv})
self.has_paired()
def step4(self, encrypted_data):
"""Last pairing step."""
chacha = chacha20.Chacha20Cipher(self._session_key, self._session_key)
decrypted_tlv_bytes = chacha.decrypt(encrypted_data, nounce="PS-Msg06".encode())
if not decrypted_tlv_bytes:
raise exceptions.AuthenticationError("data decrypt failed")
decrypted_tlv = hap_tlv8.read_tlv(decrypted_tlv_bytes)
_LOGGER.debug("PS-Msg06: %s", decrypted_tlv)
atv_identifier = decrypted_tlv[TlvValue.Identifier]
atv_signature = decrypted_tlv[TlvValue.Signature]
atv_pub_key = decrypted_tlv[TlvValue.PublicKey]
log_binary(
_LOGGER,
"Device",
Identifier=atv_identifier,
Signature=atv_signature,
Public=atv_pub_key,
)
# TODO: verify signature here
return HapCredentials(
atv_pub_key, self._auth_private, atv_identifier, self.pairing_id
)
def step3(self, additional_data=None):
"""Third pairing step."""
ios_device_x = hkdf_expand(
"Pair-Setup-Controller-Sign-Salt",
"Pair-Setup-Controller-Sign-Info",
binascii.unhexlify(self._session.key),
)
self._session_key = hkdf_expand(
"Pair-Setup-Encrypt-Salt",
"Pair-Setup-Encrypt-Info",
binascii.unhexlify(self._session.key),
)
device_info = ios_device_x + self.pairing_id + self._auth_public
device_signature = self._signing_key.sign(device_info)
tlv = {
TlvValue.Identifier: self.pairing_id,
TlvValue.PublicKey: self._auth_public,
TlvValue.Signature: device_signature,
}
if additional_data:
tlv.update(additional_data)
chacha = chacha20.Chacha20Cipher(self._session_key, self._session_key)
encrypted_data = chacha.encrypt(
hap_tlv8.write_tlv(tlv), nounce="PS-Msg05".encode()
)
log_binary(_LOGGER, "Data", Encrypted=encrypted_data)
return encrypted_data
def _m5_setup(self, _):
session_key = hkdf_expand(
"Pair-Setup-Encrypt-Salt",
"Pair-Setup-Encrypt-Info",
binascii.unhexlify(self.session.key),
)
acc_device_x = hkdf_expand(
"Pair-Setup-Accessory-Sign-Salt",
"Pair-Setup-Accessory-Sign-Info",
binascii.unhexlify(self.session.key),
)
device_info = acc_device_x + self.unique_id + self.keys.auth_pub
signature = self.keys.sign.sign(device_info)
tlv = write_tlv({
TlvValue.Identifier: self.unique_id,
TlvValue.PublicKey: self.keys.auth_pub,
TlvValue.Signature: signature,
})
chacha = chacha20.Chacha20Cipher(session_key, session_key)
encrypted = chacha.encrypt(tlv, nounce="PS-Msg06".encode())
msg = messages.crypto_pairing({
TlvValue.SeqNo: b"\x06",
TlvValue.EncryptedData: encrypted
})
self.has_paired = True
self.send_to_client(msg)
def verify1(self, credentials, session_pub_key, encrypted):
"""First verification step."""
self._shared = self._verify_private.exchange(
X25519PublicKey.from_public_bytes(session_pub_key)
)
session_key = hkdf_expand(
"Pair-Verify-Encrypt-Salt", "Pair-Verify-Encrypt-Info", self._shared
)
chacha = chacha20.Chacha20Cipher(session_key, session_key)
decrypted_tlv = hap_tlv8.read_tlv(
chacha.decrypt(encrypted, nounce="PV-Msg02".encode())
)
identifier = decrypted_tlv[TlvValue.Identifier]
signature = decrypted_tlv[TlvValue.Signature]
if identifier != credentials.atv_id:
raise exceptions.AuthenticationError("incorrect device response")
info = session_pub_key + bytes(identifier) + self._public_bytes
ltpk = Ed25519PublicKey.from_public_bytes(bytes(credentials.ltpk))
try:
ltpk.verify(bytes(signature), bytes(info))
except InvalidSignature as ex:
raise exceptions.AuthenticationError("signature error") from ex
device_info = self._public_bytes + credentials.client_id + session_pub_key
device_signature = Ed25519PrivateKey.from_private_bytes(credentials.ltsk).sign(
device_info
)
tlv = hap_tlv8.write_tlv(
{
TlvValue.Identifier: credentials.client_id,
TlvValue.Signature: device_signature,
}
)
return chacha.encrypt(tlv, nounce="PV-Msg03".encode())
def _m1_verify(self, pairing_data):
server_pub_key = self.keys.verify_pub.public_bytes(
encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw)
client_pub_key = pairing_data[TlvValue.PublicKey]
shared_key = self.keys.verify.exchange(
X25519PublicKey.from_public_bytes(client_pub_key))
session_key = hkdf_expand("Pair-Verify-Encrypt-Salt",
"Pair-Verify-Encrypt-Info", shared_key)
info = server_pub_key + self.unique_id + client_pub_key
signature = self.keys.sign.sign(info)
tlv = write_tlv({
TlvValue.Identifier: self.unique_id,
TlvValue.Signature: signature
})
chacha = chacha20.Chacha20Cipher(session_key, session_key)
encrypted = chacha.encrypt(tlv, nounce="PV-Msg02".encode())
msg = messages.crypto_pairing({
TlvValue.SeqNo: b"\x02",
TlvValue.PublicKey: server_pub_key,
TlvValue.EncryptedData: encrypted,
})
self.output_key = hkdf_expand("MediaRemote-Salt",
"MediaRemote-Write-Encryption-Key",
shared_key)
self.input_key = hkdf_expand("MediaRemote-Salt",
"MediaRemote-Read-Encryption-Key",
shared_key)
log_binary(_LOGGER,
"Keys",
Output=self.output_key,
Input=self.input_key)
self.send_to_client(msg)
def enable_encryption(self, output_key: bytes, input_key: bytes) -> None:
"""Enable encryption with the specified keys."""
self._chacha = chacha20.Chacha20Cipher(output_key,
input_key,
nonce_length=12)
def enable_encryption(self, output_key, input_key):
"""Enable encryption with the specified keys."""
self._chacha = chacha20.Chacha20Cipher(output_key, input_key)
def enable_encryption(self, output_key: bytes, input_key: bytes) -> None:
"""Enable encryption with specified keys."""
self.chacha = chacha20.Chacha20Cipher(output_key, input_key)
self.state.has_authenticated = True
def enable_encryption(self, output_key: bytes, input_key: bytes) -> None:
"""Enable encryption with specified keys."""
self.chacha = chacha20.Chacha20Cipher(output_key, input_key)
