def test_okp_key_construction(crv):
key = OKPKey(crv=crv, x=os.urandom(32), d=os.urandom(32), optional_params={'ALG': 'EDDSA'})
assert _is_valid_okp_key(key)
serialized = key.encode()
_ = CoseKey.decode(serialized)
def test_set_curve_in_key():
with pytest.raises(CoseException) as excinfo:
key = OKPKey(crv='Ed25519', d=os.urandom(32))
assert "Unknown COSE header or key attribute" in str(excinfo)
key = OKPKey(crv='ED25519', d=os.urandom(32))
assert key.crv == Ed25519
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_fail_on_illegal_kty(crv, kty):
params = {KpKty: kty}
with pytest.raises(CoseIllegalKeyType) as excinfo:
_ = OKPKey(crv=crv, x=os.urandom(32), d=os.urandom(32), optional_params=params)
assert "Illegal key type in OKP COSE Key" in str(excinfo.value)
def remote_pubkey(self) -> RPK:
""" Returns the remote ephemeral public key. """
if self.cipher_suite.dh_curve in [X448, X25519]:
return OKPKey(x=self.g_y, crv=self.cipher_suite.dh_curve)
else:
return EC2Key(x=self.g_y, crv=self.cipher_suite.dh_curve)
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 test_okp_key_generation_encoding_decoding(crv):
trails = 256
for i in range(trails):
okp_test = OKPKey.generate_key(crv=crv)
okp_encoded = okp_test.encode()
okp_decoded = CoseKey.decode(okp_encoded)
assert _is_valid_okp_key(okp_decoded)
def local_pubkey(self) -> RPK:
""" Returns the local ephemeral public key. """
if self.cipher_suite.dh_curve in [X448, X25519]:
return OKPKey(x=self.g_x, crv=self.cipher_suite.dh_curve)
else:
# TODO:
pass
def remote_pubkey(self) -> RPK:
""" Returns the remote ephemeral public key. """
if self.cipher_suite.dh_curve in [X448, X25519]:
return OKPKey(x=self.g_x, crv=self.cipher_suite.dh_curve)
else:
# TODO: implement NIST curves
pass
def local_pubkey(self) -> RPK:
""" Returns the local ephemeral public key. """
# Is this a good criterion? (Possibly there doesn't need to be a
# distinction; self.cipher_suite.dh_curve.keyclass(...) could do)
if self.cipher_suite.dh_curve in [X448, X25519]:
return OKPKey(x=self.g_y, crv=self.cipher_suite.dh_curve)
else:
return EC2Key(x=self.g_y, crv=self.cipher_suite.dh_curve)
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_key_ops_setter_getter():
key = OKPKey.generate_key('ED25519')
key.key_ops = [SignOp]
assert SignOp in key.key_ops
with pytest.raises(CoseIllegalKeyOps) as excinfo:
key.key_ops = [MacVerifyOp]
assert "Invalid COSE key operation" in str(excinfo)
def __init__(self, cred_idr, cred, auth_key):
super().__init__()
# test with static connection identifier and static ephemeral key
self.ephemeral_key = OKPKey(
crv=X25519,
x=unhexlify("71a3d599c21da18902a1aea810b2b6382ccd8d5f9bf0195281754c5ebcaf301e"),
d=unhexlify("fd8cd877c9ea386e6af34ff7e606c4b64ca831c8ba33134fd4cd7167cabaecda"))
self.cred_idr = cred_idr
self.cred = cred
self.auth_key = auth_key
self.supported = [CipherSuite0, CipherSuite1]
self.resp = self.create_responder()
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 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 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)
async def main():
parser = argparse.ArgumentParser()
# 51.75.194.248
parser.add_argument("ip", help="IP address of EDHOC responder", type=str)
parser.add_argument("--epk",
help="Use a preset ephemeral key",
action="store_true")
args = parser.parse_args()
context = await Context.create_client_context()
supported = [CipherSuite0]
if args.epk:
ephemeral_key = OKPKey(
crv=X25519,
x=unhexlify(
"898ff79a02067a16ea1eccb90fa52246f5aa4dd6ec076bba0259d904b7ec8b0c"
),
d=unhexlify(
"8f781a095372f85b6d9f6109ae422611734d7dbfa0069a2df2935bb2e053bf35"
))
else:
ephemeral_key = None
init = Initiator(corr=Correlation.CORR_1,
method=Method.SIGN_SIGN,
conn_idi=unhexlify(b''),
cred_idi=cred_id_initiator,
auth_key=initiator_authkey,
cred=initiator_cert,
remote_cred_cb=get_peer_cred,
supported_ciphers=supported,
selected_cipher=CipherSuite0,
ephemeral_key=ephemeral_key)
msg_1 = init.create_message_one()
# assert msg_1 == unhexlify(b"01005820898ff79a02067a16ea1eccb90fa52246f5aa4dd6ec076bba0259d904b7ec8b0c40")
request = Message(code=Code.POST,
payload=msg_1,
uri=f"coap://[{args.ip}]/.well-known/edhoc")
logging.info("POST (%s) %s", init.edhoc_state, request.payload)
response = await context.request(request).response
logging.info("CHANGED (%s) %s", init.edhoc_state, response.payload)
msg_3 = init.create_message_three(response.payload)
# assert msg_3 == unhexlify(_msg_3)
logging.info("POST (%s) %s", init.edhoc_state, request.payload)
request = Message(code=Code.POST,
payload=msg_3,
uri=f"coap://[{args.ip}]/.well-known/edhoc")
response = await context.request(request).response
conn_idi, conn_idr, aead, hashf = init.finalize()
logging.info('EDHOC key exchange successfully completed:')
logging.info(f" - connection IDr: {conn_idr}")
logging.info(f" - connection IDi: {conn_idi}")
logging.info(f" - aead algorithm: {aead}")
logging.info(f" - hash algorithm: {hashf}")
logging.info(
f" - OSCORE secret : {init.exporter('OSCORE Master Secret', 16)}")
logging.info(
f" - OSCORE salt : {init.exporter('OSCORE Master Salt', 8)}")
def test(self):
print('\nTest: ' + __name__ + '.' + type(self).__name__)
private_key = OKPKey(
crv=curves.Ed25519,
x=binascii.unhexlify('64f38ea84b153c7be87349f78261ca46e90f1613a3ceb2ae02c010193631e07d'),
d=binascii.unhexlify('6820977a9be08d676dac7ee19e1595d0552894ee2d71feb1d7b1d2a9f31754fd'),
optional_params={
keyparam.KpKid: b'ExampleEd25519',
keyparam.KpKeyOps: [keyops.SignOp, keyops.VerifyOp],
}
)
print('Private Key: {}'.format(encode_diagnostic(cbor2.loads(private_key.encode()))))
# Primary block
prim_dec = self._get_primary_item()
prim_enc = cbor2.dumps(prim_dec)
print('Primary Block: {}'.format(encode_diagnostic(prim_dec)))
print('Encoded: {}'.format(encode_diagnostic(prim_enc)))
# Security target block
target_dec = self._get_target_item()
target_enc = cbor2.dumps(target_dec)
content_plaintext = target_dec[4]
print('Target Block: {}'.format(encode_diagnostic(target_dec)))
print('Plaintext: {}'.format(encode_diagnostic(content_plaintext)))
# Combined AAD
ext_aad_dec = self._get_aad_item()
ext_aad_enc = cbor2.dumps(ext_aad_dec)
print('External AAD: {}'.format(encode_diagnostic(ext_aad_dec)))
print('Encoded: {}'.format(encode_diagnostic(ext_aad_enc)))
msg_obj = Sign1Message(
phdr={
headers.Algorithm: algorithms.EdDSA,
},
uhdr={
headers.KID: private_key.kid,
},
payload=content_plaintext,
# Non-encoded parameters
external_aad=ext_aad_enc,
)
msg_obj.key = private_key
# COSE internal structure
cose_struct_enc = msg_obj._sig_structure
cose_struct_dec = cbor2.loads(cose_struct_enc)
print('COSE Structure: {}'.format(encode_diagnostic(cose_struct_dec)))
print('Encoded: {}'.format(encode_diagnostic(cose_struct_enc)))
# Encoded message
message_enc = msg_obj.encode(tag=False)
message_dec = cbor2.loads(message_enc)
# Detach the payload
content_signature = message_dec[2]
message_dec[2] = None
self._print_message(message_dec, recipient_idx=4)
message_enc = cbor2.dumps(message_dec)
# ASB structure
asb_dec = self._get_asb_item([
msg_obj.cbor_tag,
message_enc
])
asb_enc = self._get_asb_enc(asb_dec)
print('ASB: {}'.format(encode_diagnostic(asb_dec)))
print('Encoded: {}'.format(encode_diagnostic(asb_enc)))
bpsec_dec = self._get_bpsec_item(
block_type=BlockType.BIB,
asb_dec=asb_dec,
)
bpsec_enc = cbor2.dumps(bpsec_dec)
print('BPSec block: {}'.format(encode_diagnostic(bpsec_dec)))
print('Encoded: {}'.format(encode_diagnostic(bpsec_enc)))
# Change from detached payload
message_dec[2] = content_signature
decode_obj = Sign1Message.from_cose_obj(message_dec)
decode_obj.external_aad = ext_aad_enc
decode_obj.key = private_key
verify_valid = decode_obj.verify_signature()
self.assertTrue(verify_valid)
print('Loopback verify:', verify_valid)
bundle = self._assemble_bundle([prim_enc, bpsec_enc, target_enc])
print('Total bundle: {}'.format(encode_diagnostic(bundle)))
def test_fail_on_missing_key_values(crv):
with pytest.raises(CoseInvalidKey) as excinfo:
_ = OKPKey(crv=crv)
assert "Either the public values or the private value must be specified" in str(excinfo.value)
def test_okp_key_generation(crv):
key = OKPKey.generate_key(crv)
assert _is_valid_okp_key(key)
def test_key_generation_with_optional_parameters():
key = OKPKey.generate_key(crv='ED25519', optional_params={'KpKid': 4})
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)
with open("responder-cert.pem", "rb") as f:
c = b"".join(f.readlines())
responder_cert = x509.load_pem_x509_certificate(c)
cert_hash = X5T.from_certificate(Sha256Trunc64, responder_cert.tbs_certificate_bytes).encode()
cred_id_responder = {headers.X5t: cert_hash}
with open("responder-authkey.pem", "rb") as f:
k = b"".join(f.readlines())
key = load_pem_private_key(k, password=None)
responder_authkey = OKPKey(crv=Ed25519,
d=key.private_bytes(serialization.Encoding.Raw,
serialization.PrivateFormat.Raw,
serialization.NoEncryption()),
x=key.public_key().public_bytes(serialization.Encoding.Raw,
serialization.PublicFormat.Raw))
class EdhocResponder(resource.Resource):
def __init__(self, cred_idr, cred, auth_key):
super().__init__()
# test with static connection identifier and static ephemeral key
self.ephemeral_key = OKPKey(
crv=X25519,
x=unhexlify("71a3d599c21da18902a1aea810b2b6382ccd8d5f9bf0195281754c5ebcaf301e"),
d=unhexlify("fd8cd877c9ea386e6af34ff7e606c4b64ca831c8ba33134fd4cd7167cabaecda"))
