def send_packet(key_list: 'KeyList', # Key list object
gateway: 'Gateway', # Gateway object
log_queue: 'Queue[log_queue_data]', # Multiprocessing queue for logged messages
assembly_packet: bytes, # Padded plaintext assembly packet
onion_pub_key: Optional[bytes] = None, # Recipient v3 Onion Service address
log_messages: Optional[bool] = None, # When True, log the message assembly packet
log_as_ph: Optional[bool] = None # When True, log assembly packet as placeholder data
) -> None:
"""Encrypt and send assembly packet.
The assembly packets are encrypted using a symmetric message key.
TFC provides forward secrecy via a hash ratchet, meaning previous
message key is replaced by it's BLAKE2b hash. The preimage
resistance of the hash function prevents retrospective decryption of
ciphertexts in cases of physical compromise.
The hash ratchet state (the number of times initial message key has
been passed through BLAKE2b) is delivered to recipient inside the
hash ratchet counter. This counter is encrypted with a static
symmetric key called the header key.
The encrypted assembly packet and encrypted harac are prepended with
datagram headers that tell if the encrypted assembly packet is a
command or a message. Packets with MESSAGE_DATAGRAM_HEADER also
contain a second header, which is the public key of the recipient's
Onion Service. This allows the ciphertext to be requested from Relay
Program's server by the correct contact.
Once the encrypted_packet has been output, the hash ratchet advances
to the next state, and the assembly packet is pushed to log_queue,
which is read by the `log_writer_loop` process (that can be found
at src.common.db_logs). This approach prevents IO delays caused by
`input_loop` reading the log file from affecting the `sender_loop`
process, which could reveal schedule information under traffic
masking mode.
"""
if len(assembly_packet) != ASSEMBLY_PACKET_LENGTH:
raise CriticalError("Invalid assembly packet PT length.")
if onion_pub_key is None:
keyset = key_list.get_keyset(LOCAL_PUBKEY)
header = COMMAND_DATAGRAM_HEADER
else:
keyset = key_list.get_keyset(onion_pub_key)
header = MESSAGE_DATAGRAM_HEADER + onion_pub_key
harac_in_bytes = int_to_bytes(keyset.tx_harac)
encrypted_harac = encrypt_and_sign(harac_in_bytes, keyset.tx_hk)
encrypted_message = encrypt_and_sign(assembly_packet, keyset.tx_mk)
encrypted_packet = header + encrypted_harac + encrypted_message
gateway.write(encrypted_packet)
keyset.rotate_tx_mk()
log_queue.put((onion_pub_key, assembly_packet, log_messages, log_as_ph, key_list.master_key))
def split_to_assembly_packets(payload: bytes, p_type: str) -> List[bytes]:
"""Split payload to assembly packets.
Messages and commands are compressed to reduce transmission time.
Files have been compressed at earlier phase, before B85 encoding.
If the compressed message can not be sent over one packet, it is
split into multiple assembly packets with headers. Long messages
are encrypted with inner layer of XSalsa20-Poly1305 to provide
sender based control over partially transmitted data. Regardless
of packet size, files always have an inner layer of encryption,
and it is added in earlier phase. Commands do not need
sender-based control, so they are only delivered with hash that
makes integrity check easy.
First assembly packet in file transmission is prepended with 8-byte
packet counter that tells sender and receiver how many packets the
file transmission requires.
"""
s_header = {MESSAGE: M_S_HEADER, FILE: F_S_HEADER, COMMAND: C_S_HEADER}[p_type]
l_header = {MESSAGE: M_L_HEADER, FILE: F_L_HEADER, COMMAND: C_L_HEADER}[p_type]
a_header = {MESSAGE: M_A_HEADER, FILE: F_A_HEADER, COMMAND: C_A_HEADER}[p_type]
e_header = {MESSAGE: M_E_HEADER, FILE: F_E_HEADER, COMMAND: C_E_HEADER}[p_type]
if p_type in [MESSAGE, COMMAND]:
payload = zlib.compress(payload, level=COMPRESSION_LEVEL)
if len(payload) < PADDING_LEN:
padded = byte_padding(payload)
packet_list = [s_header + padded]
else:
if p_type == MESSAGE:
msg_key = csprng()
payload = encrypt_and_sign(payload, msg_key)
payload += msg_key
elif p_type == FILE:
payload = bytes(FILE_PACKET_CTR_LEN) + payload
elif p_type == COMMAND:
payload += hash_chain(payload)
padded = byte_padding(payload)
p_list = split_byte_string(padded, item_len=PADDING_LEN)
if p_type == FILE:
p_list[0] = int_to_bytes(len(p_list)) + p_list[0][FILE_PACKET_CTR_LEN:]
packet_list = ([l_header + p_list[0]] +
[a_header + p for p in p_list[1:-1]] +
[e_header + p_list[-1]])
return packet_list
def test_long_file(self):
# Setup
packet = Packet('*****@*****.**', self.contact, ORIGIN_CONTACT_HEADER, FILE, self.settings)
packet.long_active = True
compressed = zlib.compress(os.urandom(10000), level=COMPRESSION_LEVEL)
file_key = os.urandom(KEY_LENGTH)
encrypted = encrypt_and_sign(compressed, key=file_key)
encrypted += file_key
encoded = base64.b85encode(encrypted)
file_data = int_to_bytes(1000) + int_to_bytes(10000)+ b'testfile.txt' + US_BYTE + encoded
packets = split_to_assembly_packets(file_data, FILE)
for p in packets:
packet.add_packet(p)
# Test
self.assertIsNone(packet.assemble_and_store_file())
self.assertTrue(os.path.isfile(f'{DIR_RX_FILES}Alice/testfile.txt'))
self.assertEqual(os.path.getsize(f'{DIR_RX_FILES}Alice/testfile.txt'), 10000)
def test_group_remove_datagram(self) -> None:
# Setup
packet = self.create_packet(GROUP_MSG_MEMBER_REM_HEADER +
bytes(GROUP_ID_LENGTH) + int_to_bytes(2) +
nick_to_pub_key('Alice') +
nick_to_pub_key('Bob'))
self.queues[GATEWAY_QUEUE].put((self.ts, packet))
# Test
self.assertIsNone(src_incoming(*self.args, unit_test=True))
self.assertEqual(self.queues[DST_MESSAGE_QUEUE].qsize(), 0)
def test_rotate_tx_mk(self):
self.assertIsNone(self.keyset.rotate_tx_mk())
self.assertEqual(
self.keyset.tx_mk,
blake2b(bytes(SYMMETRIC_KEY_LENGTH) + int_to_bytes(INITIAL_HARAC),
digest_size=SYMMETRIC_KEY_LENGTH))
self.assertEqual(self.keyset.rx_mk, bytes(SYMMETRIC_KEY_LENGTH))
self.assertEqual(self.keyset.tx_hk, bytes(SYMMETRIC_KEY_LENGTH))
self.assertEqual(self.keyset.rx_hk, bytes(SYMMETRIC_KEY_LENGTH))
self.assertEqual(self.keyset.tx_harac, 1)
self.assertEqual(self.keyset.rx_harac, INITIAL_HARAC)
def test_file_datagram(self):
# Setup
packet = self.create_packet(FILE_DATAGRAM_HEADER + int_to_bytes(2) +
nick_to_pub_key('Alice') +
nick_to_pub_key('Bob') + 200 * b'a')
self.queues[GATEWAY_QUEUE].put((self.ts, packet))
# Test
self.assertIsNone(src_incoming(*self.args, unittest=True))
self.assertEqual(self.queues[DST_MESSAGE_QUEUE].qsize(), 0)
self.assertEqual(self.queues[F_TO_FLASK_QUEUE].qsize(), 2)
def test_noise_packet_interrupts_file(self):
# Setup
packet = Packet('*****@*****.**', self.contact, ORIGIN_CONTACT_HEADER, FILE, self.settings)
compressed = zlib.compress(os.urandom(10000), level=COMPRESSION_LEVEL)
file_key = os.urandom(KEY_LENGTH)
encrypted = encrypt_and_sign(compressed, key=file_key)
encrypted += file_key
encoded = base64.b85encode(encrypted)
file_data = int_to_bytes(1000) + int_to_bytes(10000) + b'testfile.txt' + US_BYTE + encoded
packets = split_to_assembly_packets(file_data, FILE)
packets = packets[:20]
packets.append(byte_padding(P_N_HEADER)) # Add cancel packet
for p in packets:
packet.add_packet(p)
# Test
self.assertEqual(len(packet.assembly_pt_list), 0) # Cancel packet empties packet list
self.assertFalse(packet.long_active)
self.assertFalse(packet.is_complete)
self.assertEqual(packet.log_masking_ctr, len(packets))
def setUp(self):
self.msg = ("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean condimentum consectetur purus quis"
" dapibus. Fusce venenatis lacus ut rhoncus faucibus. Cras sollicitudin commodo sapien, sed bibendu"
"m velit maximus in. Aliquam ac metus risus. Sed cursus ornare luctus. Integer aliquet lectus id ma"
"ssa blandit imperdiet. Ut sed massa eget quam facilisis rutrum. Mauris eget luctus nisl. Sed ut el"
"it iaculis, faucibus lacus eget, sodales magna. Nunc sed commodo arcu. In hac habitasse platea dic"
"tumst. Integer luctus aliquam justo, at vestibulum dolor iaculis ac. Etiam laoreet est eget odio r"
"utrum, vel malesuada lorem rhoncus. Cras finibus in neque eu euismod. Nulla facilisi. Nunc nec ali"
"quam quam, quis ullamcorper leo. Nunc egestas lectus eget est porttitor, in iaculis felis sceleris"
"que. In sem elit, fringilla id viverra commodo, sagittis varius purus. Pellentesque rutrum loborti"
"s neque a facilisis. Mauris id tortor placerat, aliquam dolor ac, venenatis arcu.")
self.contact = create_contact()
self.settings = Settings(logfile_masking=True)
compressed = zlib.compress(b'abcdefghijk', level=COMPRESSION_LEVEL)
file_key = os.urandom(KEY_LENGTH)
encrypted = encrypt_and_sign(compressed, key=file_key)
encrypted += file_key
encoded = base64.b85encode(encrypted)
self.short_f_data = (int_to_bytes(1) + int_to_bytes(2) + b'testfile.txt' + US_BYTE + encoded)
def mock_file_preprocessor(payload):
if len(payload) < 255:
padded = byte_padding(payload)
packet_list = [F_S_HEADER + padded]
else:
payload = bytes(8) + payload
padded = byte_padding(payload)
p_list = split_byte_string(padded, item_len=255)
packet_list = ([F_L_HEADER + int_to_bytes(len(p_list)) + p_list[0][8:]] +
[F_A_HEADER + p for p in p_list[1:-1]] +
[F_E_HEADER + p_list[-1]])
return packet_list
def test_function(self):
# Setup
no_msg = int_to_bytes(1)
cmd_data = b'*****@*****.**' + US_BYTE + no_msg
window_list = WindowList()
contact_list = ContactList()
settings = Settings()
master_key = MasterKey()
# Test
self.assertFR("Error: Could not find 'user_data/ut_logs'.",
display_logs, cmd_data, window_list, contact_list,
settings, master_key)
def test_disabled_file_reception_raises_fr_with_end_packet(self):
# Setup
packet = Packet('*****@*****.**', self.contact, ORIGIN_CONTACT_HEADER, FILE, self.settings)
packet.long_active = True
compressed = zlib.compress(os.urandom(10000), level=COMPRESSION_LEVEL)
file_key = os.urandom(KEY_LENGTH)
encrypted = encrypt_and_sign(compressed, key=file_key)
encrypted += file_key
encoded = base64.b85encode(encrypted)
file_data = int_to_bytes(1000) + int_to_bytes(10000)+ b'testfile.txt' + US_BYTE + encoded
packets = split_to_assembly_packets(file_data, FILE)
for p in packets[:-1]:
self.assertIsNone(packet.add_packet(p))
packet.contact.file_reception = False
# Test
for p in packets[-1:]:
self.assertFR("Alert! File reception disabled mid-transfer.", packet.add_packet, p)
self.assertEqual(packet.log_masking_ctr, len(packets))
def group_add_member(group_name: str,
purp_members: List['bytes'],
contact_list: 'ContactList',
group_list: 'GroupList',
settings: 'Settings',
queues: 'QueueDict',
master_key: 'MasterKey',
_: Optional[bytes] = None
) -> None:
"""Add new member(s) to a specified group."""
if group_name not in group_list.get_list_of_group_names():
if yes(f"Group {group_name} was not found. Create new group?", abort=False, head=1):
group_create(group_name, purp_members, contact_list, group_list, settings, queues, master_key)
return None
else:
raise FunctionReturn("Group creation aborted.", head=0, delay=1, tail_clear=True)
purp_pub_keys = set(purp_members)
pub_keys = set(contact_list.get_list_of_pub_keys())
before_adding = set(group_list.get_group(group_name).get_list_of_member_pub_keys())
ok_pub_keys_set = set(pub_keys & purp_pub_keys)
new_in_group_set = set(ok_pub_keys_set - before_adding)
end_assembly = list(before_adding | new_in_group_set)
rejected = list(purp_pub_keys - pub_keys)
already_in_g = list(before_adding & purp_pub_keys)
new_in_group = list(new_in_group_set)
ok_pub_keys = list(ok_pub_keys_set)
if len(end_assembly) > settings.max_number_of_group_members:
raise FunctionReturn(f"Error: TFC settings only allow {settings.max_number_of_group_members} "
f"members per group.", head_clear=True)
group = group_list.get_group(group_name)
group.add_members([contact_list.get_contact_by_pub_key(k) for k in new_in_group])
command = GROUP_ADD + group.group_id + b''.join(ok_pub_keys)
queue_command(command, settings, queues)
group_management_print(ADDED_MEMBERS, new_in_group, contact_list, group_name)
group_management_print(ALREADY_MEMBER, already_in_g, contact_list, group_name)
group_management_print(UNKNOWN_ACCOUNTS, rejected, contact_list, group_name)
if new_in_group:
if yes("Publish the list of new members to involved?", abort=False):
add_packet = (GROUP_MSG_MEMBER_ADD_HEADER
+ group.group_id
+ int_to_bytes(len(before_adding))
+ b''.join(before_adding)
+ b''.join(new_in_group))
queue_to_nc(add_packet, queues[RELAY_PACKET_QUEUE])
def new_master_key(self):
password = MasterKey.new_password()
salt = os.urandom(32)
rounds = 1
assert isinstance(salt, bytes)
while True:
time_start = time.monotonic()
master_key, memory = argon2_kdf(password, salt, rounds, local_testing=False)
time_final = time.monotonic() - time_start
if time_final > 3.0:
self.master_key = master_key
master_key_hash = hash_chain(master_key)
ensure_dir(f'{DIR_USER_DATA}/')
with open(self.file_name, 'wb+') as f:
f.write(salt
+ master_key_hash
+ int_to_bytes(rounds)
+ int_to_bytes(memory))
break
else:
rounds *= 2
def test_successful_command_decryption(self):
# Setup
command = byte_padding(b'test')
encrypted_message = encrypt_and_sign(command, KEY_LENGTH*b'\x01')
encrypted_harac = encrypt_and_sign(int_to_bytes(1), KEY_LENGTH*b'\x01')
packet = COMMAND_PACKET_HEADER + encrypted_harac + encrypted_message
keyset = self.key_list.get_keyset(LOCAL_ID)
keyset.tx_harac = 1
# Test
assembly_pt, account, origin = decrypt_assembly_packet(packet, self.window_list, self.contact_list, self.key_list)
self.assertEqual(assembly_pt, command)
self.assertEqual(account, LOCAL_ID)
self.assertEqual(origin, ORIGIN_USER_HEADER)
def group_rm_member(group_name: str,
purp_members: List[bytes],
contact_list: 'ContactList',
group_list: 'GroupList',
settings: 'Settings',
queues: 'QueueDict',
master_key: 'MasterKey',
_: Optional[bytes] = None) -> None:
"""Remove member(s) from the specified group or remove the group itself."""
if not purp_members:
group_rm_group(group_name, contact_list, group_list, settings, queues,
master_key)
if group_name not in group_list.get_list_of_group_names():
raise FunctionReturn(f"Group '{group_name}' does not exist.",
head_clear=True)
purp_pub_keys = set(purp_members)
pub_keys = set(contact_list.get_list_of_pub_keys())
before_removal = set(
group_list.get_group(group_name).get_list_of_member_pub_keys())
ok_pub_keys_set = set(purp_pub_keys & pub_keys)
removable_set = set(before_removal & ok_pub_keys_set)
remaining = list(before_removal - removable_set)
not_in_group = list(ok_pub_keys_set - before_removal)
rejected = list(purp_pub_keys - pub_keys)
removable = list(removable_set)
ok_pub_keys = list(ok_pub_keys_set)
group = group_list.get_group(group_name)
group.remove_members(removable)
command = GROUP_REMOVE + group.group_id + b''.join(ok_pub_keys)
queue_command(command, settings, queues)
group_management_print(REMOVED_MEMBERS, removable, contact_list,
group_name)
group_management_print(NOT_IN_GROUP, not_in_group, contact_list,
group_name)
group_management_print(UNKNOWN_ACCOUNTS, rejected, contact_list,
group_name)
if removable and remaining and yes(
"Publish the list of removed members to remaining members?",
abort=False):
rem_packet = (GROUP_MSG_MEMBER_REM_HEADER + group.group_id +
int_to_bytes(len(remaining)) + b''.join(remaining) +
b''.join(removable))
queue_to_nc(rem_packet, queues[RELAY_PACKET_QUEUE])
def test_expired_harac_raises_fr(self):
# Setup
encrypted_message = encrypt_and_sign(PRIVATE_MESSAGE_HEADER + byte_padding(b'test'), 32 * b'\x01')
harac_in_bytes = int_to_bytes(1)
encrypted_harac = encrypt_and_sign(harac_in_bytes, 32 * b'\x01')
packet = MESSAGE_PACKET_HEADER + encrypted_harac + encrypted_message + ORIGIN_CONTACT_HEADER + b'*****@*****.**'
window_list = WindowList(nicks=['Alice', 'local'])
contact_list = ContactList(nicks=['Alice', 'local'])
key_list = KeyList(nicks=['Alice', 'local'])
keyset = key_list.get_keyset('*****@*****.**')
keyset.rx_harac = 3
# Test
self.assertFR("Warning! Received packet from Alice had an expired hash ratchet counter.", decrypt_assembly_packet, packet, window_list, contact_list, key_list)
def process_message_datagram(ts: 'datetime', packet: bytes, header: bytes,
buf_key: bytes, queues: 'QueueDict') -> None:
"""Process message or public key datagram."""
packets_to_dst = queues[DST_MESSAGE_QUEUE]
onion_pub_key, payload = separate_header(packet,
ONION_SERVICE_PUBLIC_KEY_LENGTH)
packet_str = header.decode() + b85encode(payload)
ts_bytes = int_to_bytes(int(ts.strftime("%Y%m%d%H%M%S%f")[:-4]))
buffer_to_flask(packet_str, onion_pub_key, ts, header, buf_key)
if header == MESSAGE_DATAGRAM_HEADER:
packets_to_dst.put(header + ts_bytes + onion_pub_key +
ORIGIN_USER_HEADER + payload)
def queue_packet(mk, hk, tx_harac, packet, onion_pub_key=None):
"""Create encrypted datagram."""
if onion_pub_key is None:
header = b''
queue = queues[COMMAND_DATAGRAM_HEADER]
packet = split_to_assembly_packets(packet, COMMAND)[0]
else:
header = onion_pub_key + ORIGIN_CONTACT_HEADER
queue = queues[MESSAGE_DATAGRAM_HEADER]
packet = split_to_assembly_packets(packet, MESSAGE)[0]
encrypted_harac = encrypt_and_sign(int_to_bytes(tx_harac), hk)
encrypted_message = encrypt_and_sign(packet, mk)
encrypted_packet = header + encrypted_harac + encrypted_message
queue.put((datetime.datetime.now(), encrypted_packet))
def check_for_files(url_token: str, onion_pub_key: bytes, onion_addr: str,
short_addr: str, session: 'Session',
queues: 'QueueDict') -> None:
"""See if a file is available from contact.."""
try:
file_data = session.get(f"http://{onion_addr}.onion/{url_token}/files",
stream=True).content
if file_data:
ts = datetime.now()
ts_bytes = int_to_bytes(int(ts.strftime("%Y%m%d%H%M%S%f")[:-4]))
packet = FILE_DATAGRAM_HEADER + ts_bytes + onion_pub_key + ORIGIN_CONTACT_HEADER + file_data
queues[DST_MESSAGE_QUEUE].put(packet)
rp_print(f"File from contact {short_addr}", ts)
except requests.exceptions.RequestException:
pass
def load_file_data(self) -> None:
"""Load file name, size and data from specified path."""
if not os.path.isfile(self.path):
raise FunctionReturn("Error: File not found.")
self.name = (self.path.split('/')[-1]).encode()
self.name_length_check()
byte_size = os.path.getsize(self.path)
if byte_size == 0:
raise FunctionReturn("Error: Target file is empty.")
self.size = int_to_bytes(byte_size)
self.size_print = readable_size(byte_size)
with open(self.path, 'rb') as f:
self.data = f.read()
def setUp(self):
self.cmd_data = b'*****@*****.**' + US_BYTE + int_to_bytes(1)
self.ts = datetime.now()
self.window_list = WindowList(nicks=['Alice', 'Bob'])
self.window = self.window_list.get_window('*****@*****.**')
self.window.type_print = 'contact'
self.contact_list = ContactList(nicks=['Alice', 'Bob'])
self.group_list = GroupList()
self.settings = Settings()
self.master_key = MasterKey()
self.time = datetime.fromtimestamp(
struct.unpack('<L',
binascii.unhexlify('08ceae02'))[0]).strftime('%H:%M')
self.o_struct_pack = struct.pack
struct.pack = lambda *_: binascii.unhexlify('08ceae02')
def send_packet(packet: bytes,
key_list: 'KeyList',
settings: 'Settings',
gateway: 'Gateway',
l_queue: 'Queue',
rx_account: str = None,
tx_account: str = None,
logging: bool = None) -> None:
"""Encrypt and send assembly packet.
Load keys from key database, encrypt assembly packet, add
headers, send and optionally log the assembly packet.
:param packet: Padded plaintext assembly packet
:param key_list: Key list object
:param settings: Settings object
:param gateway: Gateway object
:param l_queue: Multiprocessing queue for logged messages
:param rx_account: Recipient account
:param tx_account: Sender's account associated with recipient's account
:param logging: When True, log the assembly packet
:return: None
"""
if len(packet) != 256:
raise CriticalError("Invalid assembly packet PT length.")
if rx_account is None:
keyset = key_list.get_keyset('local')
header = COMMAND_PACKET_HEADER
trailer = b''
else:
keyset = key_list.get_keyset(rx_account)
header = MESSAGE_PACKET_HEADER
trailer = tx_account.encode() + US_BYTE + rx_account.encode()
harac_in_bytes = int_to_bytes(keyset.tx_harac)
encrypted_harac = encrypt_and_sign(harac_in_bytes, keyset.tx_hek)
encrypted_message = encrypt_and_sign(packet, keyset.tx_key)
encrypted_packet = header + encrypted_harac + encrypted_message + trailer
transmit(encrypted_packet, settings, gateway)
keyset.rotate_tx_key()
if logging and rx_account is not None:
l_queue.put((packet, rx_account, settings, key_list.master_key))
def store_settings(self) -> None:
"""Store settings to encrypted database."""
attribute_list = [self.__getattribute__(k) for k in self.key_list]
# Convert attributes into constant length byte string
pt_bytes = b''
for a in attribute_list:
if isinstance(a, bool): pt_bytes += bool_to_bytes(a)
elif isinstance(a, int): pt_bytes += int_to_bytes(a)
elif isinstance(a, float): pt_bytes += double_to_bytes(a)
elif isinstance(a, str): pt_bytes += str_to_bytes(a)
else: raise CriticalError("Invalid attribute type in settings.")
ct_bytes = encrypt_and_sign(pt_bytes, self.master_key.master_key)
ensure_dir(f'{DIR_USER_DATA}/')
with open(self.file_name, 'wb+') as f:
f.write(ct_bytes)
def test_function(self):
# Setup
ts = datetime.datetime.now()
no_msg = int_to_bytes(1)
cmd_data = b'*****@*****.**' + US_BYTE + no_msg
window_list = WindowList()
contact_list = ContactList()
settings = Settings()
master_key = MasterKey()
write_log_entry(F_S_HEADER + bytes(255), '*****@*****.**', settings,
master_key)
# Test
self.assertIsNone(
export_logs(cmd_data, ts, window_list, contact_list, settings,
master_key))
os.remove('Unittest - Plaintext log (None)')
cleanup()
def setUp(self):
self.unittest_dir = cd_unittest()
self.cmd_data = int_to_bytes(1) + nick_to_pub_key("Bob")
self.ts = datetime.now()
self.window_list = WindowList(nicks=['Alice', 'Bob'])
self.window = self.window_list.get_window(nick_to_pub_key("Bob"))
self.window.type_print = 'contact'
self.window.name = 'Bob'
self.window.type = WIN_TYPE_CONTACT
self.contact_list = ContactList(nicks=['Alice', 'Bob'])
self.group_list = GroupList()
self.settings = Settings()
self.master_key = MasterKey()
self.args = (self.ts, self.window_list, self.contact_list,
self.group_list, self.settings, self.master_key)
time_float = struct.unpack('<L', bytes.fromhex('08ceae02'))[0]
self.time = datetime.fromtimestamp(time_float).strftime("%H:%M:%S.%f")[:-4]
def queue_packet(key, hek, tx_harac, packet, rx_account=None):
if rx_account is None:
header = COMMAND_PACKET_HEADER
trailer = b''
queue = queues[COMMAND_PACKET_HEADER]
packet = split_to_assembly_packets(packet, COMMAND)[0]
else:
header = MESSAGE_PACKET_HEADER
trailer = ORIGIN_CONTACT_HEADER + rx_account
queue = queues[MESSAGE_PACKET_HEADER]
packet = split_to_assembly_packets(packet, MESSAGE)[0]
encrypted_harac = encrypt_and_sign(int_to_bytes(tx_harac), hek)
encrypted_message = encrypt_and_sign(packet, key)
encrypted_packet = header + encrypted_harac + encrypted_message + trailer
queue.put((datetime.datetime.now(), encrypted_packet))
time.sleep(0.1)
def print_logs(user_input: 'UserInput',
window: 'Window',
contact_list: 'ContactList',
settings: 'Settings',
c_queue: 'Queue',
master_key: 'MasterKey') -> None:
"""Print log files on screen."""
try:
no_messages_str = user_input.plaintext.split()[1]
if not no_messages_str.isdigit():
raise FunctionReturn("Specified invalid number of messages to print.")
no_messages = int(no_messages_str)
except IndexError:
no_messages = 0
packet = LOG_DISPLAY_HEADER + window.uid.encode() + US_BYTE + int_to_bytes(no_messages)
queue_command(packet, settings, c_queue)
access_history(window, contact_list, settings, master_key, no_messages)
def update_delivery_time(self) -> None:
"""Calculate transmission time.
Transmission time is based on average delays and settings.
"""
no_packets = self.count_number_of_packets()
if self.settings.session_traffic_masking:
avg_delay = self.settings.traffic_masking_static_delay + (
self.settings.traffic_masking_random_delay / 2)
if self.settings.multi_packet_random_delay:
avg_delay += (self.settings.max_duration_of_random_delay / 2)
total_time = len(self.window) * no_packets * avg_delay
total_time *= 2 # Accommodate command packets between file packets
total_time += no_packets * TRAFFIC_MASKING_QUEUE_CHECK_DELAY
else:
# Determine total data to be transmitted over serial
rs = RSCodec(2 * self.settings.session_serial_error_correction)
total_data = 0
for c in self.window:
data = os.urandom(PACKET_LENGTH) + c.rx_account.encode(
) + c.tx_account.encode()
enc_data = rs.encode(data)
total_data += no_packets * len(enc_data)
# Determine time required to send all data
total_time = 0.0
if self.settings.local_testing_mode:
total_time += no_packets * LOCAL_TESTING_PACKET_DELAY
else:
total_bauds = total_data * BAUDS_PER_BYTE
total_time += total_bauds / self.settings.session_serial_baudrate
total_time += no_packets * self.settings.txm_inter_packet_delay
if self.settings.multi_packet_random_delay:
total_time += no_packets * (
self.settings.max_duration_of_random_delay / 2)
# Update delivery time
self.time_bytes = int_to_bytes(int(total_time))
self.time_print = str(datetime.timedelta(seconds=int(total_time)))
def rotate_tx_mk(self) -> None:
"""\
Update Transmitter Program's tx-message key and tx-harac.
Replacing the key with its hash provides per-message forward
secrecy for sent messages. The hash ratchet used is also known
as the SCIMP Ratchet[1], and it is widely used, e.g., as part of
Signal's Double Ratchet[2].
To ensure the hash ratchet does not fall into a short cycle of
keys, the harac (that is a non-repeating value) is used as an
additional input when deriving the next key.
[1] (pp. 17-18) https://netzpolitik.org/wp-upload/SCIMP-paper.pdf
[2] https://signal.org/blog/advanced-ratcheting/
"""
self.tx_mk = blake2b(self.tx_mk + int_to_bytes(self.tx_harac), digest_size=SYMMETRIC_KEY_LENGTH)
self.tx_harac += 1
self.store_keys()
def queue_file(window: 'Window', settings: 'Settings', f_queue: 'Queue',
gateway: 'Gateway') -> None:
"""Ask file path and load file data."""
path = ask_path_gui("Select file to send...", settings, get_file=True)
file = File(path, window, settings, gateway)
name = file.name.decode()
size = file.size.decode()
payload = file.plaintext
if len(payload) < 255:
padded = byte_padding(payload)
packet_list = [F_S_HEADER + padded]
else:
payload = bytes(8) + payload
padded = byte_padding(payload)
p_list = split_byte_string(padded, item_len=255)
# < number of packets >
packet_list = (
[F_L_HEADER + int_to_bytes(len(p_list)) + p_list[0][8:]] +
[F_A_HEADER + p for p in p_list[1:-1]] + [F_E_HEADER + p_list[-1]])
for p in packet_list:
assert len(p) == 256
if settings.confirm_sent_files:
if not yes(
f"Send {name} ({size}) to {window.type} {window.name} "
f"({len(packet_list)} packets, time: {file.time_s})?",
tail=1):
raise FunctionReturn("File selection aborted.")
if settings.session_trickle:
log_m_dictionary = dict((c.rx_account, c.log_messages) for c in window)
for p in packet_list:
f_queue.put((p, log_m_dictionary))
else:
for c in window:
for p in packet_list:
f_queue.put((p, settings, c.rx_account, c.tx_account,
c.log_messages, window.uid))