def do_counter_mode(k, iv, x, blocksize, ivsize):
aes = AES_ENCRYPT(k)
long_k = bytearray()
n = ceil(len(x) / blocksize)
for i in range(0, n):
c = aes((iv + i).to_bytes(ivsize, "big"))
long_k += c
return xor(x, long_k[:len(x)])
def build_key(key, c1, c2, c3):
xm12, xm13, xm23 = xor(c1, c2), xor(c1, c3), xor(c2, c3)
for i in range(0, len(c1)):
if key[i] != 0:
continue
if c1[i] == c2[i] or c1[i] == c3[i] or c2[i] == c3[i]:
continue
m12, m13, m23 = xm12[i], xm13[i], xm23[i]
if within_range(m13) and within_range(m23):
key[i] = ord(" ") ^ c3[i]
elif within_range(m12) and within_range(m23):
key[i] = ord(" ") ^ c2[i]
elif within_range(m12) and within_range(m13):
key[i] = ord(" ") ^ c1[i]
def decrypt_cbc(msg, key, iv):
cipher = AES.new(key, AES.MODE_ECB)
blocks = [msg[i:i + 32] for i in range(0, len(msg), 32)]
decrypted = ''
prev = str2hex(iv)
for block in blocks:
dec = cipher.decrypt(block.decode('hex')).encode('hex')
d = xor(prev, dec)
prev = block
decrypted += d
return decrypted
def encrypt_cbc(msg, key, iv):
cipher = AES.new(key, AES.MODE_ECB)
msg = pad(msg, 16)
msg = str2hex(msg)
blocks = [msg[i:i + 32] for i in range(0, len(msg), 32)]
encrypted = ''
en = str2hex(iv)
for block in blocks:
ip = xor(en, block)
en = cipher.encrypt(ip.decode('hex')).encode('hex')
encrypted += en
return encrypted
def encrypt_cbc(msg, key, iv='\x00' * 16, is_base64=False):
cipher = AES.new(key, AES.MODE_ECB)
if is_base64:
msg = base64.b64decode(msg)
msg = pad(msg, 16)
blocks = [msg[i:i + 16] for i in range(0, len(msg), 16)]
encrypted = ''
en = iv
for block in blocks:
ip = xor(en, block)
en = cipher.encrypt(ip)
encrypted += en
return encrypted
def decrypt_cbc(ct_string, k_string):
ct, k = bytes.fromhex(ct_string), bytes.fromhex(k_string)
assert len(ct) % BLOCKSIZE == 0, "Invalid format"
n = len(ct) // BLOCKSIZE
aes_decrypt = AES_DECRYPT(k)
m = bytearray()
for i in range(n - 1):
start, mid, end = i * BLOCKSIZE, (i + 1) * BLOCKSIZE, (i +
2) * BLOCKSIZE
cx, cy = ct[start:mid], ct[mid:end]
d = aes_decrypt(cy)
m += xor(cx, d)
return unpad(m)
def decrypt_cbc(msg, key, iv='\x00' * 16, is_base64=False):
cipher = AES.new(key, AES.MODE_ECB)
if is_base64:
print('Decoding base64...')
msg = base64.b64decode(msg)
blocks = [msg[i:i + 16] for i in range(0, len(msg), 16)]
decrypted = ''
prev = iv
for block in blocks:
dec = cipher.decrypt(block)
d = xor(prev, dec)
prev = block
decrypted += d
return decrypted
def encrypt_cbc(pt_string, k_string, blocksize=16):
pt, k = bytearray(pt_string, 'utf-8'), bytes.fromhex(k_string)
pad(pt)
print(pt)
n = len(pt) // BLOCKSIZE
current = urandom(BLOCKSIZE) #IV
aes_encrypt = AES_ENCRYPT(k)
ct = bytearray(current)
for i in range(n):
start, end = i * blocksize, (i + 1) * blocksize
m = pt[start:end]
d = xor(m, current)
current = aes_encrypt(d)
ct += current
print(len(ct))
return ct.hex()
def __init__(self, buffer):
self.packet = buffer[0:74]
self.frame_sync = self.packet[0:11]
self.data_block = self.packet[11:56]
self.batt_cond = (self.packet[13:15][::-1])
self.message_type = self.packet[15:18]
self.unit_addr = int((self.packet[18:35][::-1]), 2)
self.pressure = int((self.packet[35:42][::-1]), 2)
self.batt_charge = \
("{}%".format(int(int((self.packet[42:49][::-1]), 2) / 127 * 100)))
self.spare = self.packet[49]
self.valve_ckt_stat = self.packet[50]
self.conf_ind = self.packet[51]
self.turbine = self.packet[52]
self.motion = self.packet[53]
self.mkr_batt = self.packet[54]
self.mkr_light = self.packet[55]
self.checkbitsRx = self.packet[56:74]
self.batt_cond_dict = {
"11": "OK",
"10": "Low",
"01": "Very Low",
"00": "Not Monitored"
}
self.batt_cond_text = self.batt_cond_dict[self.batt_cond]
if (self.message_type == "111"):
if (self.conf_ind == "0"):
self.arm_status = "Arming"
else:
self.arm_status = "Armed"
else:
self.arm_status = "Normal"
self.generator = '1111001101000001111' # BCH generator polynomial
self.cipher_key = '101011011101110000' # XOR cipher key
self.data_block = helpers.reverse(self.data_block)
self.checkbits = helpers.checkbits(self.data_block, self.generator)
self.checkbits_cipher = helpers.xor(self.checkbits, self.cipher_key)
self.valid = (self.checkbits_cipher == self.checkbitsRx) # a match?
#!/usr/bin/env python3
import sys
import binascii
sys.path.append('..')
from helpers import abort, xor
if __name__ == "__main__":
if len(sys.argv) == 3 and not sys.argv[1] == '-h':
i1 = binascii.unhexlify(sys.argv[1])
i2 = binascii.unhexlify(sys.argv[2])
xored = xor(i1, i2)
print(str(binascii.hexlify(xored), 'ascii'))
elif len(sys.argv) == 4 and sys.argv[1] == '-h':
i1 = binascii.unhexlify(sys.argv[2])
i2 = binascii.unhexlify(sys.argv[3])
xored = xor(i1, i2)
print(str(xored, 'ascii'))
else:
abort(f'{sys.argv[0]}: [-h] input1 input2')
