def testMACValidation():
"""
Tests whether the server properly rejects messages when their MAC is modified.
"""
print("Testing validation of individual MAC bits...")
failBits = []
for maskBit in range(0, 96):
rejected = False
try:
# formulate a bit mask based on the current mask bit index
mask = bytearray([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
maskIndex = int((maskBit - (maskBit % 8)) / 8)
mask[maskIndex] = (0x80 >> (maskBit % 8))
if args.verbose:
maskBinString = ''.join(format(x, 'b').zfill(8) for x in mask)
print("\tTesting bit %d, mask: %s" % (maskBit, maskBinString))
else:
print("+", end="")
# connect to the server and do a handshake
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((args.host, args.port))
tls = TLSConnection(sock)
# assign mask as tweak
tls.macTweak = bytearray(mask)
tls.handshakeClientCert()
# send a packet
tls.send("GET / HTTP/1.0\n\n\n")
# try to read some data back
data = tls.read()
except (TLSRemoteAlert, socket.error):
rejected = True
if args.verbose:
print("\tBit %d rejected correctly!" % maskBit)
except (TLSAbruptCloseError, socket.error):
rejected = True
if args.verbose:
print("\tBit %d rejected correctly!" % maskBit)
if not rejected:
failBits.append(maskBit)
if not args.verbose:
print("")
if len(failBits) > 0:
macValidationIssue = getIssueTemplate("MAC_VALIDATION_ERROR")
macValidationIssue.findings = ', '.join(str(b) for b in failBits)
report.addIssue(macValidationIssue)
print("The following modified MAC bits were incorrectly accepted: ",
end='')
print(', '.join(str(b) for b in failBits))
else:
print("All modified MAC bits were correctly rejected.")
msg.RID = ''
msg.STIME = 0
msgType = 0
msgType = setBit(msgType, 0) # Identity
msgType = setBit(msgType, 1) # Authenticate
msg.TYPE = msgType
msg.BODY = '{"token":"foo"}'
data = Packet.Pack(msg)
connection.write(data)
## P2P message
msg.RID = 'a'
msg.TYPE = 0
msg.BODY = 'x'
data = Packet.Pack(msg)
data = connection.read() # You must implement your own tcp receiver
msg = Packet.UnPack(data) # Must catch error
print msg
raw_input('Press enter to exit')
connection.close()
msg.RID = ''
msg.STIME = 0
msgType = 0
msgType = setBit(msgType, 0) # Identity
msgType = setBit(msgType, 1) # Authenticate
msg.TYPE = msgType
msg.BODY = '{"token":"foo"}'
data = Packet.Pack(msg)
connection.write(data)
## P2P message
msg.RID = 'a'
msg.TYPE = 0
msg.BODY = 'x'
data = Packet.Pack(msg)
data = connection.read() # You must implement your own tcp receiver
msg = Packet.UnPack(data) # Must catch error
print msg
raw_input('Press enter to exit')
connection.close()