class GsCipher:
gs_encryption_key = None
gs_iv = None
gs_speck = None
mode = None
logger = None
key_int = None
iv_int = None
def __init__(self):
key_bytes = array.array('B', [])
for k in self.gs_encryption_key:
key_bytes.append(k)
self.key_int = int.from_bytes(key_bytes,
byteorder='little',
signed=False)
iv_bytes = array.array('B', [])
for i in self.gs_iv:
iv_bytes.append(i)
self.iv_int = int.from_bytes(iv_bytes,
byteorder='little',
signed=False)
self.gs_speck = SpeckCipher(self.key_int,
key_size=128,
block_size=64,
mode=self.mode,
init=self.iv_int)
def encrypt(self, ax25_packet):
if self.gs_speck.mode == 'CBC':
self.gs_speck.update_iv(self.iv_int)
ax25_packet_encrypted = array.array('B', ax25_packet[:16])
ax25_packet_temp = array.array('B', ax25_packet[16:])
for i in range(0, 232, 8):
plaintext_int = int.from_bytes(ax25_packet_temp[i:(i + 8)],
byteorder='big',
signed=False)
ciphertext = self.gs_speck.encrypt(plaintext_int)
ciphertext_bytes = bytearray.fromhex('{:032x}'.format(ciphertext))
for c in ciphertext_bytes[8:]:
ax25_packet_encrypted.append(c)
ax25_packet_encrypted.extend([0x00] * 5)
return ax25_packet_encrypted
def decrypt(self, ax25_packet_encrypted):
if self.gs_speck.mode == 'CBC':
self.gs_speck.update_iv(self.iv_int)
ax25_packet = array.array('B', ax25_packet_encrypted[:16])
ax25_packet_temp = ax25_packet_encrypted[16:]
for i in range(0, 232, 8):
ciphertext_int = int.from_bytes(ax25_packet_temp[i:(i + 8)],
byteorder='big',
signed=False)
plaintext = self.gs_speck.decrypt(ciphertext_int)
plaintext_bytes = bytearray.fromhex('{:032x}'.format(plaintext))
for p in plaintext_bytes[8:]:
ax25_packet.append(p)
return ax25_packet
