def setup_dh_key(selected_cipher: int, private_bytes: bytes):
if CipherSuite.from_id(selected_cipher).dh_curve in [X448, X25519]:
return OKPKey(d=private_bytes, crv=CipherSuite.from_id(selected_cipher).dh_curve)
elif CipherSuite.from_id(selected_cipher).dh_curve in [P256]:
return EC2Key(d=private_bytes, crv=CipherSuite.from_id(selected_cipher).sign_curve)
else:
raise ValueError("Illegal DH keys.")
def test_responder_finalize(responder, test_vectors):
responder.msg_1 = MessageOne.decode(test_vectors['S']['message_1'])
responder.msg_2 = MessageTwo.decode(
responder.create_message_two(test_vectors['S']['message_1']))
responder.msg_3 = MessageThree.decode(test_vectors['S']['message_3'])
decoded = EdhocMessage.decode(
responder._decrypt(responder.msg_3.ciphertext))
if KID.identifier in cbor2.loads(test_vectors['I']['cred_id']):
assert decoded[0] == EdhocMessage.encode_bstr_id(
cbor2.loads(test_vectors['I']['cred_id'])[KID.identifier])
else:
assert decoded[0] == cbor2.loads(test_vectors['I']['cred_id'])
assert decoded[1] == test_vectors['S']['signature_3']
if getattr(responder, 'remote_authkey', None) is None:
warnings.warn(NoRemoteKey())
return
c_i, c_r, app_aead, app_hash = responder.finalize(
test_vectors['S']['message_3'])
assert c_i == test_vectors['I']['conn_id']
assert c_r == test_vectors['R']['conn_id']
assert app_aead == CipherSuite.from_id(
test_vectors['I']['selected']).app_aead.identifier
assert app_hash == CipherSuite.from_id(
test_vectors['I']['selected']).app_hash.identifier
def test_responder_message2(responder, test_vectors):
responder.msg_1 = MessageOne.decode(test_vectors['S']['message_1'])
hash_func = CipherSuite.from_id(
responder.msg_1.selected_cipher).hash.hash_cls
crv = CipherSuite.from_id(responder.msg_1.selected_cipher).dh_curve
assert responder.shared_secret(
responder.ephemeral_key, OKPKey(x=responder.g_x,
crv=crv)) == test_vectors['S']['g_xy']
assert responder._prk2e == test_vectors['S']['prk_2e']
assert responder._prk3e2m == test_vectors['S']['prk_3e2m']
assert responder.data_2 == test_vectors['S']['data_2']
assert responder._th2_input == test_vectors['S']['input_th_2']
assert responder.cred_id == cbor2.loads(test_vectors['R']['cred_id'])
assert responder.transcript(
hash_func, responder._th2_input) == test_vectors['S']['th_2']
assert responder._hkdf2(
16, 'K_2m', prk=responder._prk3e2m) == test_vectors['S']['k_2m']
assert responder._hkdf2(
13, 'IV_2m', prk=responder._prk3e2m) == test_vectors['S']['iv_2m']
assert responder._mac(responder._hkdf2, 'K_2m', 16, 'IV_2m', 13,
responder._th2_input, responder._prk3e2m,
responder.aad2_cb) == test_vectors['S']['mac_2']
assert responder.signature_or_mac2(
test_vectors['S']['mac_2']) == test_vectors['S']['signature_2']
assert responder._p_2e == test_vectors['S']['p_2e']
assert responder._hkdf2(
len(responder._p_2e), 'KEYSTREAM_2',
prk=responder._prk2e) == test_vectors['S']['keystream_2']
assert responder.ciphertext_2 == test_vectors['S']['ciphertext_2']
assert responder.create_message_two(
test_vectors['S']['message_1']) == test_vectors['S']['message_2']
def setup_sign_key(selected_cipher: int, private_bytes: bytes):
if CipherSuite.from_id(selected_cipher).sign_curve in [Ed448, Ed25519]:
return OKPKey(d=private_bytes,
crv=CipherSuite.from_id(selected_cipher).sign_curve,
optional_params={KpAlg: CipherSuite.from_id(selected_cipher).sign_alg})
elif CipherSuite.from_id(selected_cipher).sign_alg == Es256:
return EC2Key(d=private_bytes, alg=Es256, crv=CipherSuite.from_id(selected_cipher).sign_curve)
else:
raise ValueError("Illegal COSE curve.")
def test_message1_encode(test_vectors):
msg = MessageOne(
method_corr=test_vectors["S"]["method_corr"],
cipher_suites=[
CipherSuite.from_id(x) for x in test_vectors["I"]["supported"]
],
selected_cipher=CipherSuite.from_id(test_vectors["I"]["selected"]),
g_x=test_vectors["I"]["g_x"],
conn_idi=test_vectors["I"]["conn_id"],
external_aad=test_vectors["I"]["ad_1"])
assert msg.encode(
test_vectors["S"]["corr"]) == test_vectors["S"]["message_1"]
def test_initiator_finalize(initiator, test_vectors):
initiator.msg_1 = MessageOne.decode(initiator.create_message_one())
initiator.msg_2 = MessageTwo.decode(test_vectors['S']['message_2'])
initiator.msg_3 = MessageThree.decode(
initiator.create_message_three(test_vectors['S']['message_2']))
c_i, c_r, app_aead, app_hash = initiator.finalize()
assert c_i == test_vectors['I']['conn_id']
assert c_r == test_vectors['R']['conn_id']
assert app_aead == CipherSuite.from_id(
test_vectors['I']['selected']).app_aead.identifier
assert app_hash == CipherSuite.from_id(
test_vectors['I']['selected']).app_hash.identifier
def test_initiator_finalize(initiator, test_vectors):
initiator.msg_1 = MessageOne.decode(initiator.create_message_one())
initiator.msg_2 = MessageTwo.decode(test_vectors['S']['message_2'])
if getattr(initiator, 'remote_authkey', None) is None:
warnings.warn(NoRemoteKey())
return
initiator.msg_3 = MessageThree.decode(initiator.create_message_three(test_vectors['S']['message_2']))
c_i, c_r, app_aead, app_hash = initiator.finalize()
assert c_i == test_vectors['I']['conn_id']
assert c_r == test_vectors['R']['conn_id']
assert app_aead == CipherSuite.from_id(test_vectors['I']['selected']).app_aead.identifier
assert app_hash == CipherSuite.from_id(test_vectors['I']['selected']).app_hash.identifier
def responder(ephemeral_responder_key, test_vectors):
if test_vectors['R']['cred_type'] == 0:
local_cred = cbor2.loads(test_vectors['R']['cred'])
local_auth_key = None
else:
local_cred = CoseKey.decode(test_vectors['R']['cred'])
local_auth_key = CoseKey.decode(test_vectors['R']['cred'])
if test_vectors['I']['cred_type'] == 0:
remote_cred = cbor2.loads(test_vectors['I']['cred'])
remote_auth_key = None
else:
remote_cred = CoseKey.decode(test_vectors['I']['cred'])
remote_auth_key = CoseKey.decode(test_vectors['I']['cred'])
responder = Responder(
conn_idr=test_vectors["R"]["conn_id"],
cred_idr=cbor2.loads(test_vectors['R']['cred_id']),
auth_key=CoseKey.decode(test_vectors['R']['auth_key']),
cred=(local_cred, local_auth_key),
supported_ciphers=[
CipherSuite.from_id(c) for c in test_vectors["R"]["supported"]
],
remote_cred_cb=lambda arg: (remote_cred, remote_auth_key),
ephemeral_key=ephemeral_responder_key)
responder.cred_idi = test_vectors['I']['cred_id']
return responder
def cipher_suite(self) -> 'CS':
if self.msg_1 is None:
raise EdhocException("Message 1 not received. Cannot derive selected cipher suite.")
else:
if not self._verify_cipher_selection(self.msg_1.selected_cipher, self.msg_1.cipher_suites):
raise EdhocException("Invalid cipher suite setup")
return CipherSuite.from_id(self.msg_1.selected_cipher)
def initiator(ephemeral_initiator_key, test_vectors):
if test_vectors['I']['cred_type'] == 0:
local_auth_key = None
local_cred = cbor2.loads(test_vectors['I']['cred'])
else:
local_auth_key = CoseKey.decode(test_vectors['I']['cred'])
local_cred = CoseKey.decode(test_vectors['I']['cred'])
if test_vectors['R']['cred_type'] == 0:
remote_auth_key = None
remote_cred = cbor2.loads(test_vectors['R']['cred'])
else:
remote_auth_key = CoseKey.decode(test_vectors['R']['cred'])
remote_cred = CoseKey.decode(test_vectors['R']['cred'])
return Initiator(
corr=test_vectors['S']['corr'],
method=test_vectors['S']['method'],
cred=(local_cred, local_auth_key),
cred_idi=cbor2.loads(test_vectors['I']['cred_id']),
auth_key=CoseKey.decode(test_vectors['I']['auth_key']),
selected_cipher=test_vectors['I']['selected'],
supported_ciphers=[CipherSuite.from_id(c) for c in test_vectors["I"]["supported"]],
conn_idi=test_vectors['I']['conn_id'],
remote_cred_cb=lambda x: (remote_cred, remote_auth_key),
ephemeral_key=ephemeral_initiator_key,
)
def decode(cls, received: bytes) -> 'MessageOne':
"""
Tries to decode the bytes as an EDHOC MessageOne.
:param received: Bytes to decode.
:raises EdhocInvalidMessage: Decoding routine for MessageOne failed.
:returns: An EDHOC MessageOne object.
"""
decoded = super().decode(received)
method_corr = decoded[cls.METHOD_CORR]
if isinstance(decoded[cls.CIPHERS], int):
selected_cipher = decoded[cls.CIPHERS]
supported_ciphers = [decoded[cls.CIPHERS]]
elif isinstance(decoded[cls.CIPHERS], list):
selected_cipher = decoded[cls.CIPHERS][0]
supported_ciphers = decoded[cls.CIPHERS][1:]
else:
raise EdhocInvalidMessage("Failed to decode bytes as MessageOne")
g_x = decoded[cls.G_X]
if decoded[cls.CONN_ID] != b'':
if isinstance(decoded[cls.CONN_ID], int):
conn_idi = EdhocMessage.decode_bstr_id(decoded[cls.CONN_ID])
else:
conn_idi = decoded[cls.CONN_ID]
else:
conn_idi = b''
msg = cls(
method_corr=method_corr,
selected_cipher=CipherSuite.from_id(selected_cipher),
cipher_suites=[CipherSuite.from_id(c) for c in supported_ciphers],
g_x=g_x,
conn_idi=conn_idi)
try:
msg.aad1 = decoded[cls.AAD1]
except IndexError:
pass
return msg
def test_initiator_message3(initiator, test_vectors):
initiator.msg_1 = MessageOne.decode(test_vectors['S']['message_1'])
initiator.msg_2 = MessageTwo.decode(test_vectors['S']['message_2'])
crv = CipherSuite.from_id(initiator._selected_cipher).dh_curve
hash_func = CipherSuite.from_id(initiator._selected_cipher).hash.hash_cls
assert initiator.data_2 == test_vectors['S']['data_2']
assert initiator._th2_input == test_vectors['S']['input_th_2']
assert initiator._prk2e == test_vectors['S']['prk_2e']
assert initiator._prk3e2m == test_vectors['S']['prk_3e2m']
assert initiator.transcript(hash_func, initiator._th2_input) == test_vectors['S']['th_2']
assert initiator._decrypt(initiator.msg_2.ciphertext) == test_vectors['S']['p_2e']
assert initiator.shared_secret(initiator.ephemeral_key, OKPKey(x=initiator.g_y, crv=crv)) == test_vectors['S'][
'g_xy']
assert initiator.data_3 == test_vectors['S']['data_3']
assert initiator._th3_input == test_vectors['S']['input_th_3']
assert initiator.transcript(hash_func, initiator._th3_input) == test_vectors['S']['th_3']
assert initiator.cred_id == cbor2.loads(test_vectors['I']['cred_id'])
assert initiator._prk4x3m == test_vectors['S']['prk_4x3m']
assert initiator._hkdf3(16, 'K_3m', initiator._prk4x3m) == test_vectors['S']['k_3m']
assert initiator._hkdf3(13, 'IV_3m', initiator._prk4x3m) == test_vectors['S']['iv_3m']
assert initiator._mac(
initiator.cred_idi,
initiator.cred,
initiator._hkdf3,
'K_3m',
16,
'IV_3m',
13,
initiator._th3_input,
initiator._prk4x3m,
initiator.aad2_cb) == test_vectors['S']['mac_3']
assert initiator.signature_or_mac3(test_vectors['S']['mac_3']) == test_vectors['S']['signature_3']
assert initiator._p_3ae == test_vectors['S']['p_3ae']
assert initiator._hkdf3(16, 'K_3ae', initiator._prk3e2m) == test_vectors['S']['k_3ae']
assert initiator._hkdf3(13, 'IV_3ae', initiator._prk3e2m) == test_vectors['S']['iv_3ae']
assert initiator.ciphertext_3 == test_vectors['S']['ciphertext_3']
if initiator.remote_authkey is None:
warnings.warn(NoRemoteKey())
return
assert initiator.create_message_three(test_vectors['S']['message_2']) == test_vectors['S']['message_3']
def test_message1_decode(test_vectors):
msg = MessageOne.decode(test_vectors['S']['message_1'])
assert msg.corr == test_vectors["S"]["corr"]
assert msg.method == test_vectors["S"]["method"]
assert msg.cipher_suites == [
CipherSuite.from_id(x) for x in test_vectors["I"]["supported"]
]
assert msg.selected_cipher.identifier == test_vectors["I"]["selected"]
assert msg.g_x == test_vectors["I"]["g_x"]
assert msg.conn_idi == test_vectors['I']['conn_id']
assert msg.aad1 == test_vectors['I']['ad_1']
def _generate_ephemeral_key(self) -> None:
"""
Generate a new ephemeral key if the key was not already set.
:return: None
"""
if self.ephemeral_key is not None:
return
chosen_suite = CipherSuite.from_id(self.cipher_suite)
if chosen_suite.dh_curve in [X25519, X448]:
self.ephemeral_key = OKPKey.generate_key(crv=chosen_suite.dh_curve)
else:
self.ephemeral_key = EC2Key.generate_key(crv=chosen_suite.dh_curve)
def __init__(self,
corr: Correlation,
method: Method,
cred: Union[RPK, Certificate],
cred_idi: CoseHeaderMap,
auth_key: RPK,
selected_cipher: Type['CS'],
supported_ciphers: List[Type['CS']],
remote_cred_cb: Callable[[CoseHeaderMap], Union[Certificate,
RPK]],
conn_idi: Optional[bytes] = None,
aad1_cb: Optional[Callable[..., bytes]] = None,
aad2_cb: Optional[Callable[..., bytes]] = None,
aad3_cb: Optional[Callable[..., bytes]] = None,
ephemeral_key: Optional['CK'] = None):
"""
Create an EDHOC Initiator.
:param corr: Correlation value (depends on the transport protocol).
:param method: EDHOC method type (signatures, static DH or a mix).
:param cred: The public authentication credentials of the Initiator.
:param cred_idi: The Initiator's credential identifier (a CBOR encoded COSE header map)
:param auth_key: The private authentication key (CoseKey) of the Responder.
:param selected_cipher: Provide the selected cipher.
:param supported_ciphers: A list of ciphers supported by the Responder.
:param conn_idi: The connection identifier to be used
:param remote_cred_cb: A callback that fetches the remote credentials.
:param aad1_cb: A callback to pass received additional data to the application protocol.
:param aad2_cb: A callback to pass additional data to the remote endpoint.
:param aad3_cb: A callback to pass received additional data to the application protocol.
:param ephemeral_key: Preload an (CoseKey) ephemeral key (if unset a random key will be generated).
"""
if conn_idi is None:
conn_idi = os.urandom(1)
super().__init__(cred, cred_idi, auth_key, supported_ciphers, conn_idi,
remote_cred_cb, aad1_cb, aad2_cb, aad3_cb,
ephemeral_key)
self._selected_cipher = CipherSuite.from_id(selected_cipher)
self._corr = Correlation(corr)
self._method = Method(method)
self._cred_idr = None
def ephemeral_initiator_key(test_vectors):
return OKPKey(
x=test_vectors['I']['g_x'],
d=test_vectors['I']['x'],
crv=CipherSuite.from_id(test_vectors['I']['selected']).dh_curve)
def ephemeral_responder_key(test_vectors):
return OKPKey(
x=test_vectors['R']['g_y'],
d=test_vectors['R']['y'],
crv=CipherSuite.from_id(test_vectors['I']['selected']).dh_curve)