def load_keys():
try:
tmp_keys = json.load(open(key_path))
fix_key_perms()
except:
keys['my_key'] = curve25519.Private()
save_keys()
return
for key in tmp_keys:
if key == 'my_key':
keys[key] = curve25519.Private(b64decode(tmp_keys[key]))
else:
keys[key] = curve25519.Public(b64decode(tmp_keys[key]))
def decrypt_message(self, ct, decryptor):
decryptor = self.derive_keys(decryptor)
pt = self.decrypt(ct, decryptor['message_key'], decryptor['message_counter'])
if not pt:
return None
bob_ephemeral, msg = pt[:32], pt[32:]
self.receive = decryptor
# it's encrypted with the same key it advertised.. shouldn't happen.
if bob_ephemeral == self.receive['bob'].serialize():
raise
# it's advertising the receive_pending key, we need to respond again because
# they may not have gotten it.
elif self.receive_pending \
and bob_ephemeral == self.receive_pending['bob'].serialize():
pass
# yay a new key! we need to respond.
elif not self.receive_pending \
or bob_ephemeral != self.receive_pending['bob'].serialize():
self.receive_pending = {
'alice': curve25519.Private(),
'bob': curve25519.Public(bob_ephemeral),
'receiver': True,
'acked': False
}
# uncharted territory...
else:
raise
return msg
def recover_seed(key='', modulus=None, pos=1):
# recreate the master private key from the passphrase
master = curve25519.Private(secret=sha256(key).digest())
# extract the ephemeral public key from modulus
ephem_pub = curve25519.Public(modulus[pos:pos + 32])
# compute seed with master private and ephemeral public
return (master.get_shared_key(ephem_pub), ephem_pub)
def login(self):
self._expected_message_tags = ['s1', 's2', 's3', 's4']
self._clientId = str(b64encode(os.urandom(16)), 'utf8')
self._whatsappweb_version = get_whatsappweb_version()
connection_query_name = 'connection_query'
self._expected_message_tags.append(connection_query_name)
connection_query_json = ['admin', 'init', self._whatsappweb_version, self._browser_desc, self._clientId, True]
self.ws_send(connection_query_name, connection_query_json)
connection_result = self.wait_query_pop_json(connection_query_name)
if connection_result['status'] != 200:
raise ConnectionRefusedError('Websocket connection refused')
self._qrcode = {
'must_scan': False,
'id': 0,
'ref': connection_result['ref'],
'ttl' : connection_result['ttl'] / 1000 - 1,
'time' : connection_result['time']}
self._qrcode['timeout'] = time.time() + self._qrcode['ttl']
if self._session_path and os.path.exists(self._session_path):
self.restore_session()
self.post_login()
else:
self._qrcode['must_scan'] = True
self._privateKey = curve25519.Private()
self._publicKey = self._privateKey.get_public()
bin_qrcode = gen_qrcode(self._qrcode['ref'], self._publicKey, self._clientId)
self._qrcode['qrcode'] = render_qrcode(bin_qrcode)
def verify1(self):
"""
First device verification step.
"""
self._verify_private = curve25519.Private(secret=self.seed)
self._verify_public = self._verify_private.get_public()
verify_public = self._verify_public.serialize()
return b'\x01\x00\x00\x00' + verify_public + self._auth_public
def initialize(self):
"""Initialize operation by generating new keys."""
self._signing_key = SigningKey(os.urandom(32))
self._auth_private = self._signing_key.to_seed()
self._auth_public = self._signing_key.get_verifying_key().to_bytes()
self._verify_private = curve25519.Private(secret=os.urandom(32))
self._verify_public = self._verify_private.get_public()
return self._auth_public, self._verify_public.serialize()
def test_curve25519(r):
sec1 = bytes(bytearray(r.randbytes(32)))
sec2 = bytes(bytearray(r.randbytes(32)))
pub1 = curve25519.Private(sec1).get_public()
pub2 = curve25519.Private(sec2).get_public()
session1 = r.randbytes(32)
lib.curve25519_scalarmult(session1, sec2, pub1.public)
session2 = r.randbytes(32)
lib.curve25519_scalarmult(session2, sec1, pub2.public)
assert bytearray(session1) == bytearray(session2)
shared1 = curve25519.Private(sec2).get_shared_key(pub1, hashfunc=lambda x: x)
shared2 = curve25519.Private(sec1).get_shared_key(pub2, hashfunc=lambda x: x)
assert shared1 == shared2
assert bytearray(session1) == shared1
assert bytearray(session2) == shared2
def _generate_keys(self, mkey):
"""
start to generate authentication keys, and allowing to set the
mac_key value in case exists
"""
self.private = curve25519.Private()
self.public = self.private.get_public()
self.mac_key = mkey
def generate_keys(seed):
"""Generate server encryption keys from seed."""
signing_key = SigningKey(seed)
verify_private = curve25519.Private(secret=seed)
return ServerKeys(sign=signing_key,
auth=signing_key.to_bytes(),
auth_pub=signing_key.get_verifying_key().to_bytes(),
verify=verify_private,
verify_pub=verify_private.get_public())
def __init__(self, node):
# 5.1.4. The "ntor" handshake
# This handshake uses a set of DH handshakes to compute a set of
# shared keys which the client knows are shared only with a particular
# server, and the server knows are shared with whomever sent the
# original handshake (or with nobody at all). Here we use the
# "curve25519" group and representation as specified in "Curve25519:
# new Diffie-Hellman speed records" by D. J. Bernstein.
# [The ntor handshake was added in Tor 0.2.4.8-alpha.]
self.node = node
# In this section, define:
# H(x,t) as HMAC_SHA256 with message x and key t.
# H_LENGTH = 32.
# ID_LENGTH = 20.
# G_LENGTH = 32
# PROTOID = "ntor-curve25519-sha256-1"
# t_mac = PROTOID | ":mac"
# t_key = PROTOID | ":key_extract"
# t_verify = PROTOID | ":verify"
# MULT(a,b) = the multiplication of the curve25519 point 'a' by the
# scalar 'b'.
# G = The preferred base point for curve25519 ([9])
# KEYGEN() = The curve25519 key generation algorithm, returning
# a private/public keypair.
# m_expand = PROTOID | ":key_expand"
# H is defined as hmac()
# MULT is included in the curve25519 library as get_shared_key()
# KEYGEN() is curve25519.Private()
self.protoid = 'ntor-curve25519-sha256-1'
self.t_mac = self.protoid + ':mac'
self.t_key = self.protoid + ':key_extract'
self.t_verify = self.protoid + ':verify'
self.m_expand = self.protoid + ':key_expand'
# To perform the handshake, the client needs to know an identity key
# digest for the server, and an ntor onion key (a curve25519 public
# key) for that server. Call the ntor onion key "B". The client
# generates a temporary keypair:
# x,X = KEYGEN()
self.x = curve25519.Private()
self.X = self.x.get_public()
self.B = curve25519.Public(b64decode(self.node['ntor-onion-key']))
# and generates a client-side handshake with contents:
# NODEID Server identity digest [ID_LENGTH bytes]
# KEYID KEYID(B) [H_LENGTH bytes]
# CLIENT_PK X [G_LENGTH bytes]
self.handshake = b64decode(self.node['identity'])
self.handshake += self.B.serialize()
self.handshake += self.X.serialize()
def verify1(self):
"""First device verification step."""
self._check_initialized()
self._verify_private = curve25519.Private(secret=self.seed)
self._verify_public = self._verify_private.get_public()
_log_debug('Verification keys',
Private=self._verify_private.serialize(),
Public=self._verify_public.serialize())
verify_public = self._verify_public.serialize()
return b'\x01\x00\x00\x00' + verify_public + self._auth_public
def __init__(self, loop, credentials, atv_device_id):
"""Initialize a new instance of ProxyMrpAppleTV."""
self.loop = loop
self.credentials = credentials
self.atv_device_id = atv_device_id
self.server = None
self.buffer = b''
self.has_paired = False
self.transport = None
self.chacha = None
self.connection = None
self.input_key = None
self.output_key = None
self.mapping = {
protobuf.DEVICE_INFO_MESSAGE: self.handle_device_info,
protobuf.CRYPTO_PAIRING_MESSAGE: self.handle_crypto_pairing,
}
self._shared = None
self._session_key = None
self._signing_key = SigningKey(32 * b'\x01')
self._auth_private = self._signing_key.to_seed()
self._auth_public = self._signing_key.get_verifying_key().to_bytes()
self._verify_private = curve25519.Private(secret=32 * b'\x01')
self._verify_public = self._verify_private.get_public()
self.context = SRPContext('Pair-Setup',
str(1111),
prime=constants.PRIME_3072,
generator=constants.PRIME_3072_GEN,
hash_func=hashlib.sha512,
bits_salt=128)
self.username, self.verifier, self.salt = \
self.context.get_user_data_triplet()
context_server = SRPContext('Pair-Setup',
prime=constants.PRIME_3072,
generator=constants.PRIME_3072_GEN,
hash_func=hashlib.sha512,
bits_salt=128)
self._session = SRPServerSession(
context_server, self.verifier,
binascii.hexlify(self._auth_private).decode())
def _pair_verify_one(self, tlv_objects):
"""Generate new session key pair and send a proof to the client.
@param tlv_objects: The TLV data received from the client.
@type tlv_object: dict
"""
logger.debug("Pair verify [1/2].")
client_public = tlv_objects[HAP_TLV_TAGS.PUBLIC_KEY]
private_key = curve25519.Private()
public_key = private_key.get_public()
shared_key = private_key.get_shared_key(
curve25519.Public(client_public),
# Key is hashed before being returned, we don't want it; This fixes that.
lambda x: x,
)
mac = self.state.mac.encode()
material = public_key.serialize() + mac + client_public
server_proof = self.state.private_key.sign(material)
output_key = hap_hkdf(shared_key, self.PVERIFY_1_SALT,
self.PVERIFY_1_INFO)
self._set_encryption_ctx(client_public, private_key, public_key,
shared_key, output_key)
message = tlv.encode(HAP_TLV_TAGS.USERNAME, mac, HAP_TLV_TAGS.PROOF,
server_proof)
cipher = ChaCha20Poly1305(output_key)
aead_message = bytes(
cipher.encrypt(self.PVERIFY_1_NONCE, bytes(message), b""))
data = tlv.encode(
HAP_TLV_TAGS.SEQUENCE_NUM,
b"\x02",
HAP_TLV_TAGS.ENCRYPTED_DATA,
aead_message,
HAP_TLV_TAGS.PUBLIC_KEY,
public_key.serialize(),
)
self.send_response(200)
self.send_header("Content-Type", self.PAIRING_RESPONSE_TYPE)
self.end_response(data)
def __init__(self, ref_dict, priv_key_list, pub_key_list):
self.conn_data = {
"private_key": None,
"public_key": None,
"secret": None,
"shared_secret": None,
"shared_secret_ex": None,
"aes_key": None,
"mac_key": None
}
self.conn_data["private_key"] = curve25519.Private("".join(
[chr(x) for x in priv_key_list]))
self.conn_data["public_key"] = self.conn_data[
"private_key"].get_public()
assert (self.conn_data["public_key"].serialize() == "".join(
[chr(x) for x in pub_key_list]))
self.conn_data["secret"] = base64.b64decode(ref_dict["secret"])
self.conn_data["shared_secret"] = self.conn_data[
"private_key"].get_shared_key(
curve25519.Public(self.conn_data["secret"][:32]),
lambda key: key)
shared_expended = self.conn_data["shared_secret_ex"] = HKDF(
self.conn_data["shared_secret"], 80)
check_hmac = hmac_sha256(
shared_expended[32:64],
self.conn_data["secret"][:32] + self.conn_data["secret"][64:])
if check_hmac != self.conn_data["secret"][32:64]:
raise ValueError("Error hmac mismatch")
keysDecrypted = AESDecrypt(
shared_expended[:32],
shared_expended[64:] + self.conn_data["secret"][64:])
self.conn_data["aes_key"] = keysDecrypted[:32]
self.conn_data["mac_key"] = keysDecrypted[32:64]
def _pair_verify_one(self, tlv_objects):
"""Generate new session key pair and send a proof to the client.
@param tlv_objects: The TLV data received from the client.
@type tlv_object: dict
"""
logging.debug("Pair verify [1/2].")
client_public = tlv_objects[HAP_TLV_TAGS.PUBLIC_KEY]
private_key = curve25519.Private()
public_key = private_key.get_public()
shared_key = private_key.get_shared_key(
curve25519.Public(client_public),
# Key is hashed before being returned, we don't want it; This fixes that.
lambda x: x)
mac = self._state.mac.encode()
material = public_key.serialize() + mac + client_public
server_proof = self._state.private_key.sign(material)
output_key = hap_hkdf(shared_key, PVERIFY_1_SALT, PVERIFY_1_INFO)
enc_context = {
"client_public": client_public,
"private_key": private_key,
"public_key": public_key,
"shared_key": shared_key,
"pre_session_key": output_key
}
message = tlv.encode(HAP_TLV_TAGS.USERNAME, mac, HAP_TLV_TAGS.PROOF,
server_proof)
cipher = CHACHA20_POLY1305(output_key, "python")
aead_message = bytes(
cipher.seal(PVERIFY_1_NONCE, bytearray(message), b""))
data = tlv.encode(HAP_TLV_TAGS.SEQUENCE_NUM, b'\x02',
HAP_TLV_TAGS.ENCRYPTED_DATA, aead_message,
HAP_TLV_TAGS.PUBLIC_KEY, public_key.serialize())
return data, enc_context
def _pair_verify_one(self, tlv_objects):
"""Generate new session key pair and send a proof to the client.
@param tlv_objects: The TLV data received from the client.
@type tlv_object: dict
"""
logger.debug("Pair verify [1/2].")
client_public = tlv_objects[HAP_TLV_TAGS.PUBLIC_KEY]
private_key = curve25519.Private()
public_key = private_key.get_public()
shared_key = private_key.get_shared_key(
curve25519.Public(client_public),
# Why not randomly hash the key before returning it
# so that it is incompatible with another
# implementation and force clients to use hacks?
lambda x: x)
mac = self.accessory.mac.encode()
material = public_key.serialize() + mac + client_public
server_proof = self.accessory.private_key.sign(material)
output_key = hap_hkdf(shared_key, self.PVERIFY_1_SALT, self.PVERIFY_1_INFO)
self._set_encryption_ctx(client_public, private_key, public_key,
shared_key, output_key)
message = tlv.encode(HAP_TLV_TAGS.USERNAME, mac,
HAP_TLV_TAGS.PROOF, server_proof)
cipher = CHACHA20_POLY1305(output_key, "python")
aead_message = bytes(
cipher.seal(self.PVERIFY_1_NONCE, bytearray(message), b""))
data = tlv.encode(HAP_TLV_TAGS.SEQUENCE_NUM, b'\x02',
HAP_TLV_TAGS.ENCRYPTED_DATA, aead_message,
HAP_TLV_TAGS.PUBLIC_KEY, public_key.serialize())
self.send_response(200)
self.send_header("Content-Type", self.PAIRING_RESPONSE_TYPE)
self.end_response(data)
def initLocalParams(self):
logging.info('Entering Initlocalparms')
self.data = self.restoreSession()
keySecret = None
if self.data is None:
self.mydata['clientId'] = base64.b64encode(os.urandom(16))
keySecret = os.urandom(32)
self.mydata["keySecret"] = base64.b64encode(keySecret)
else:
self.sessionExists = True
self.mydata = self.data['myData']
keySecret = base64.b64decode(self.mydata["keySecret"])
self.clientId = self.mydata['clientId']
self.privateKey = curve25519.Private(secret=keySecret)
self.publicKey = self.privateKey.get_public()
logging.info('ClientId %s' % self.clientId)
logging.info('Exiting Initlocalparms')
if self.sessionExists:
self.setConnInfoParams(base64.b64decode(self.data["secret"]))
def derive_keys(self, key=None):
# initial key exchanges.
if not key or 'bob' not in key:
master = self.long_term.get_shared_key(self.bob_long_term, self.derive_key)
key = key or {}
# we're sending
elif 'receiver' not in key:
master = self.long_term.get_shared_key(key['bob'], self.derive_key)
master += key['alice'].get_shared_key(self.bob_long_term, self.derive_key)
master += key['alice'].get_shared_key(key['bob'], self.derive_key)
# we are receiving
else:
if 'alice' not in key:
key['alice'] = curve25519.Private()
master = key['alice'].get_shared_key(self.bob_long_term, self.derive_key)
master += self.long_term.get_shared_key(key['bob'], self.derive_key)
master += key['alice'].get_shared_key(key['bob'], self.derive_key)
# derive keys
# increment counter
if 'counter' in key:
key['counter'] += 1
else:
key['counter'] = 0
mac_key = self.proto_id + '::poly1305'
master = poly1305(master + str(key['counter']), mac_key)
master = self.derive_key(master, 176)
keys = list(struct.unpack('>32s32s32s32s24s24s', master))
key['exchange_counter'] = keys.pop()
key['message_counter'] = keys.pop()
key['exchange_chaff_key'] = keys.pop()
key['chaff_key'] = keys.pop()
key['exchange_key'] = keys.pop()
key['message_key'] = keys.pop()
return key
def encrypt_msg(self, msg):
self.send = self.derive_keys(self.send)
self.print_key('Encrypting message.', self.send)
if not self.send_pending:
self.send_pending = { 'alice': curve25519.Private() }
pt = self.get_public(self.send_pending['alice'])
pt += msg
# message buffering
if 'msgs' not in self.send_pending:
self.send_pending['msgs'] = []
self.send_pending['msgs'].append(msg)
if not self.established():
return
ct = self.encrypt(pt, self.send['message_key'],
self.send['message_counter'])
blocks = self.mac_blocks(ct, self.send['chaff_key'])
return self.chaff(blocks)
def __init__(self, ref_dict, priv_key_list, pub_key_list):
self.decrypted_serialized_content = None
self.message_tag = None
self.decrypted_content = None
self.original_content = None
self.private_key = None
self.public_key = None
self.secret = None
self.shared_secret = None
self.aes_key = None
self.mac_key = None
self.private_key = curve25519.Private("".join(
[chr(x) for x in priv_key_list]))
self.public_key = self.private_key.get_public()
assert (self.public_key.serialize() == "".join(
[chr(x) for x in pub_key_list]))
self.secret = base64.b64decode(ref_dict["secret"])
self.shared_secret = self.private_key.get_shared_key(
curve25519.Public(self.secret[:32]), lambda key: key)
shared_expended = HKDF(self.shared_secret, 80)
check_hmac = hmac_sha256(shared_expended[32:64],
self.secret[:32] + self.secret[64:])
if check_hmac != self.secret[32:64]:
raise ValueError("Error hmac mismatch")
keys_decrypted = aes_decrypt(shared_expended[:32],
shared_expended[64:] + self.secret[64:])
self.aes_key = keys_decrypted[:32]
self.mac_key = keys_decrypted[32:64]
def initLocalParams(self):
logging.info('Entering Initlocalparms')
logging.info('Local storage is: {}'.format(self.isLocalStorage))
self.data = self.restoreSession()
keySecret = None
if self.data is None:
self.mydata['clientId'] = base64.b64encode(os.urandom(16))
keySecret = os.urandom(32)
self.mydata["keySecret"] = base64.b64encode(keySecret)
else:
self.sessionExists = True
if not self.isLocalStorage:
self.mydata = self.data['myData']
keySecret = base64.b64decode(self.mydata["keySecret"])
else:
self.mydata = self.data
self.data["clientToken"] = json.loads(self.data["WAToken1"])
self.data["serverToken"] = json.loads(self.data["WAToken2"])
self.data["clientId"] = json.loads(self.data["WABrowserId"])
self.mydata = self.data
self.clientId = self.mydata['clientId']
self.privateKey = curve25519.Private(secret=keySecret)
self.publicKey = self.privateKey.get_public()
logging.info('ClientId %s' % self.clientId)
logging.info('Exiting Initlocalparms')
if self.sessionExists:
if not self.isLocalStorage:
self.setConnInfoParams(base64.b64decode(self.data["secret"]))
else:
secretBundle = json.loads(self.data['WASecretBundle'])
self.encKey = base64.b64decode(secretBundle['encKey'])
self.macKey = base64.b64decode(secretBundle['macKey'])
self.subscribeStarted = False
def test_curve25519_pubkey(r):
sec = bytes(bytearray(r.randbytes(32)))
pub = curve25519.Private(sec).get_public()
res = r.randbytes(32)
lib.curve25519_scalarmult_basepoint(res, sec)
assert bytearray(res) == pub.public
if __name__ == "__main__":
# passphrase and filename as arguments
if len(sys.argv) == 3:
# Load an x.509 certificate from a file
x509 = X509.load_cert(sys.argv[2])
# Pull the modulus out of the certificate
orig_modulus = unhexlify(x509.get_pubkey().get_modulus())
(seed, ephem_pub) = recover_seed(key=sys.argv[1],
modulus=orig_modulus,
pos=80)
# no arguments, just generate a private key
else:
# deserialize master ECDH public key embedded in program
master_pub = curve25519.Public(unhexlify(MASTER_PUB_HEX))
# generate a random (yes, actually random) ECDH private key
ephem = curve25519.Private()
# derive the corresponding public key for later embedding
ephem_pub = ephem.get_public()
# combine the ECDH keys to generate the seed
seed = ephem.get_shared_key(master_pub)
prng = AESPRNG(seed)
ephem_pub = ephem_pub.serialize()
# deterministic key generation from seed
rsa = build_key(embed=ephem_pub, pos=80, randfunc=prng.randbytes)
if 'orig_modulus' in locals():
if long(hexlify(orig_modulus), 16) != long(rsa.n):
raise Exception("key recovery failed")
def __init__(self, secret=None):
self._private = curve25519.Private(secret)
def init_keys(self):
self.initialized = False
self.initial_key = { 'initial_key': True }
self.send = { 'alice': curve25519.Private() }
self.receive = { 'alice': curve25519.Private(), 'receiver': True }
def pairVerifyStep1(self, tlvData):
publicKey = tlvData['public_key']['data']
accessoryLTSK = ed25519.SigningKey(self.longTermKey, encoding='hex')
# accessoryLTPK = accessoryLTSK.get_verifying_key()
accessoryPairingID = HapHandler.getId()
iosDevicePublicKey = curve25519.Public(''.join(
[chr(x) for x in publicKey]))
# Step 1
private = curve25519.Private()
public = private.get_public()
publicSerialized = public.serialize()
# Step 2
shared = private.get_shared_key(iosDevicePublicKey,
hashfunc=lambda x: x)
# Step 3
accessoryPairingInfo = publicSerialized + accessoryPairingID + iosDevicePublicKey.serialize(
)
# Step 4
accessorySignature = accessoryLTSK.sign(accessoryPairingInfo)
# Step 5
response = []
response.append({
'type': 'identifier',
'length': len(accessoryPairingID),
'data': accessoryPairingID
})
response.append({
'type': 'signature',
'length': len(accessorySignature),
'data': accessorySignature
})
subTLV = pack(response) # tlv
# Step 6
inputKey = shared
salt = 'Pair-Verify-Encrypt-Salt'
info = 'Pair-Verify-Encrypt-Info'
key = Hkdf(salt, inputKey, hash=hashlib.sha512)
sessionKey = key.expand(info, length=32)
key = Hkdf('Control-Salt', shared, hash=hashlib.sha512)
writeKey = key.expand('Control-Write-Encryption-Key', length=32)
key = Hkdf('Control-Salt', shared, hash=hashlib.sha512)
readKey = key.expand('Control-Read-Encryption-Key', length=32)
self.sessionStorage = {
'clientPublicKey': iosDevicePublicKey.serialize(),
'secretKey': private.serialize(),
'publicKey': publicSerialized,
'sharedSec': shared,
'hkdfPairEncKey': sessionKey,
'writeKey': writeKey,
'readKey': readKey
}
# Step 7
ciphertext, mac = HapHandler.encryptAndSeal(sessionKey, 'PV-Msg02',
[ord(x) for x in subTLV])
self.sendTLVResponse([
{
'type': 'state',
'length': 1,
'data': 2
},
{
'type': 'public_key',
'length': len(publicSerialized),
'data': publicSerialized
},
{
'type': 'encrypted_data',
'length': len(ciphertext + mac),
'data': ciphertext + mac
},
])
print 'Bob ephemeral public: ' + key['bob'].serialize().encode('hex')
if 'message_key' in key:
print 'Shared key: ' + key['message_key'].encode('hex')
if 'chaff_key' in key:
print 'Chaff key: ' + key['chaff_key'].encode('hex')
if 'exchange_key' in key:
print 'Exchange shared key: ' + key['exchange_key'].encode('hex')
if 'exchange_chaff_key' in key:
print 'Exchange chaff key: ' + key['exchange_chaff_key'].encode('hex')
if 'counter' in key:
print 'Counter: %d' % key['counter']
print ''
if __name__ == "__main__":
alice_key = curve25519.Private()
bob_key = curve25519.Private()
alice = Chats(alice_key, bob_key.get_public(), 400, 8, debug=False)
bob = Chats(bob_key, alice_key.get_public(), 400, 8, debug=False)
ct = alice.encrypt_initial_keyx()
msg = bob.decrypt_msg(ct)
alice.decrypt_msg(msg['keyx'])
print '\nAlice -> Bob initial: '
ct = alice.encrypt_msg('ayy lmaoayy lmao')
msg = bob.decrypt_msg(ct)
if msg['keyx']: alice.decrypt_msg(msg['keyx'])
print 'Plaintext: %s' % msg['msg']