1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
#!/usr/bin/env python3
# Copyright (c) 2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
import random
from enum import Enum
from test_framework.messages import MAGIC_BYTES
from test_framework.p2p import P2PInterface
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import random_bitflip
from test_framework.v2_p2p import (
EncryptedP2PState,
MAX_GARBAGE_LEN,
)
class TestType(Enum):
""" Scenarios to be tested:
1. EARLY_KEY_RESPONSE - The responder needs to wait until one byte is received which does not match the 16 bytes
consisting of network magic followed by "version\x00\x00\x00\x00\x00" before sending out its ellswift + garbage bytes
2. EXCESS_GARBAGE - Disconnection happens when > MAX_GARBAGE_LEN bytes garbage is sent
3. WRONG_GARBAGE_TERMINATOR - Disconnection happens when incorrect garbage terminator is sent
4. WRONG_GARBAGE - Disconnection happens when garbage bytes that is sent is different from what the peer receives
5. SEND_NO_AAD - Disconnection happens when AAD of first encrypted packet after the garbage terminator is not filled
6. SEND_NON_EMPTY_VERSION_PACKET - non-empty version packet is simply ignored
"""
EARLY_KEY_RESPONSE = 0
EXCESS_GARBAGE = 1
WRONG_GARBAGE_TERMINATOR = 2
WRONG_GARBAGE = 3
SEND_NO_AAD = 4
SEND_NON_EMPTY_VERSION_PACKET = 5
class EarlyKeyResponseState(EncryptedP2PState):
""" Modify v2 P2P protocol functions for testing EARLY_KEY_RESPONSE scenario"""
def __init__(self, initiating, net):
super().__init__(initiating=initiating, net=net)
self.can_data_be_received = False # variable used to assert if data is received on recvbuf.
def initiate_v2_handshake(self):
"""Send ellswift and garbage bytes in 2 parts when TestType = (EARLY_KEY_RESPONSE)"""
self.generate_keypair_and_garbage()
return b""
class ExcessGarbageState(EncryptedP2PState):
"""Generate > MAX_GARBAGE_LEN garbage bytes"""
def generate_keypair_and_garbage(self):
garbage_len = MAX_GARBAGE_LEN + random.randrange(1, MAX_GARBAGE_LEN + 1)
return super().generate_keypair_and_garbage(garbage_len)
class WrongGarbageTerminatorState(EncryptedP2PState):
"""Add option for sending wrong garbage terminator"""
def generate_keypair_and_garbage(self):
garbage_len = random.randrange(MAX_GARBAGE_LEN//2)
return super().generate_keypair_and_garbage(garbage_len)
def complete_handshake(self, response):
length, handshake_bytes = super().complete_handshake(response)
# first 16 bytes returned by complete_handshake() is the garbage terminator
wrong_garbage_terminator = random_bitflip(handshake_bytes[:16])
return length, wrong_garbage_terminator + handshake_bytes[16:]
class WrongGarbageState(EncryptedP2PState):
"""Generate tampered garbage bytes"""
def generate_keypair_and_garbage(self):
garbage_len = random.randrange(1, MAX_GARBAGE_LEN)
ellswift_garbage_bytes = super().generate_keypair_and_garbage(garbage_len)
# assume that garbage bytes sent to TestNode were tampered with
return ellswift_garbage_bytes[:64] + random_bitflip(ellswift_garbage_bytes[64:])
class NoAADState(EncryptedP2PState):
"""Add option for not filling first encrypted packet after garbage terminator with AAD"""
def generate_keypair_and_garbage(self):
garbage_len = random.randrange(1, MAX_GARBAGE_LEN)
return super().generate_keypair_and_garbage(garbage_len)
def complete_handshake(self, response):
self.sent_garbage = b'' # do not authenticate the garbage which is sent
return super().complete_handshake(response)
class NonEmptyVersionPacketState(EncryptedP2PState):
""""Add option for sending non-empty transport version packet."""
def complete_handshake(self, response):
self.transport_version = random.randbytes(5)
return super().complete_handshake(response)
class MisbehavingV2Peer(P2PInterface):
"""Custom implementation of P2PInterface which uses modified v2 P2P protocol functions for testing purposes."""
def __init__(self, test_type):
super().__init__()
self.test_type = test_type
def connection_made(self, transport):
if self.test_type == TestType.EARLY_KEY_RESPONSE:
self.v2_state = EarlyKeyResponseState(initiating=True, net='regtest')
elif self.test_type == TestType.EXCESS_GARBAGE:
self.v2_state = ExcessGarbageState(initiating=True, net='regtest')
elif self.test_type == TestType.WRONG_GARBAGE_TERMINATOR:
self.v2_state = WrongGarbageTerminatorState(initiating=True, net='regtest')
elif self.test_type == TestType.WRONG_GARBAGE:
self.v2_state = WrongGarbageState(initiating=True, net='regtest')
elif self.test_type == TestType.SEND_NO_AAD:
self.v2_state = NoAADState(initiating=True, net='regtest')
elif TestType.SEND_NON_EMPTY_VERSION_PACKET:
self.v2_state = NonEmptyVersionPacketState(initiating=True, net='regtest')
super().connection_made(transport)
def data_received(self, t):
if self.test_type == TestType.EARLY_KEY_RESPONSE:
# check that data can be received on recvbuf only when mismatch from V1_PREFIX happens
assert self.v2_state.can_data_be_received
else:
super().data_received(t)
class EncryptedP2PMisbehaving(BitcoinTestFramework):
def set_test_params(self):
self.num_nodes = 1
self.extra_args = [["-v2transport=1", "-peertimeout=3"]]
def run_test(self):
self.test_earlykeyresponse()
self.test_v2disconnection()
def test_earlykeyresponse(self):
self.log.info('Sending ellswift bytes in parts to ensure that response from responder is received only when')
self.log.info('ellswift bytes have a mismatch from the 16 bytes(network magic followed by "version\\x00\\x00\\x00\\x00\\x00")')
node0 = self.nodes[0]
self.log.info('Sending first 4 bytes of ellswift which match network magic')
self.log.info('If a response is received, assertion failure would happen in our custom data_received() function')
peer1 = node0.add_p2p_connection(MisbehavingV2Peer(TestType.EARLY_KEY_RESPONSE), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_v2_handshake=False)
peer1.send_raw_message(MAGIC_BYTES['regtest'])
self.log.info('Sending remaining ellswift and garbage which are different from V1_PREFIX. Since a response is')
self.log.info('expected now, our custom data_received() function wouldn\'t result in assertion failure')
peer1.v2_state.can_data_be_received = True
peer1.send_raw_message(peer1.v2_state.ellswift_ours[4:] + peer1.v2_state.sent_garbage)
with node0.assert_debug_log(['V2 handshake timeout peer=0']):
peer1.wait_for_disconnect(timeout=5)
self.log.info('successful disconnection since modified ellswift was sent as response')
def test_v2disconnection(self):
# test v2 disconnection scenarios
node0 = self.nodes[0]
expected_debug_message = [
[], # EARLY_KEY_RESPONSE
["V2 transport error: missing garbage terminator, peer=1"], # EXCESS_GARBAGE
["V2 handshake timeout peer=2"], # WRONG_GARBAGE_TERMINATOR
["V2 transport error: packet decryption failure"], # WRONG_GARBAGE
["V2 transport error: packet decryption failure"], # SEND_NO_AAD
[], # SEND_NON_EMPTY_VERSION_PACKET
]
for test_type in TestType:
if test_type == TestType.EARLY_KEY_RESPONSE:
continue
elif test_type == TestType.SEND_NON_EMPTY_VERSION_PACKET:
node0.add_p2p_connection(MisbehavingV2Peer(test_type), wait_for_verack=True, send_version=True, supports_v2_p2p=True)
self.log.info(f"No disconnection for {test_type.name}")
else:
with node0.assert_debug_log(expected_debug_message[test_type.value], timeout=5):
peer = node0.add_p2p_connection(MisbehavingV2Peer(test_type), wait_for_verack=False, send_version=False, supports_v2_p2p=True, expect_success=False)
peer.wait_for_disconnect()
self.log.info(f"Expected disconnection for {test_type.name}")
if __name__ == '__main__':
EncryptedP2PMisbehaving().main()
|
