def encrypt(etype, key, msg_type, data):
if etype != RC4_HMAC:
raise NotImplementedError('Only RC4-HMAC supported!')
k1 = HMAC.new(key, pack('<I', msg_type)).digest()
data = random_bytes(8) + data
chksum = HMAC.new(k1, data).digest()
k3 = HMAC.new(k1, chksum).digest()
return chksum + ARC4.new(k3).encrypt(data)
def encrypt(etype, key, msg_type, data):
if etype != RC4_HMAC:
raise NotImplementedError('Only RC4-HMAC supported!')
k1 = HMAC.new(key, pack('<I', msg_type)).digest()
data = random_bytes(8) + data
chksum = HMAC.new(k1, data).digest()
k3 = HMAC.new(k1, chksum).digest()
return chksum + ARC4.new(k3).encrypt(data)
def decrypt(etype, key, msg_type, encrypted):
# MAGIC
if etype != RC4_HMAC:
return '31337313373133731337' + str(etype)
chksum = encrypted[:16]
data = encrypted[16:]
k1 = HMAC.new(key, pack('<I', msg_type)).digest()
k3 = HMAC.new(k1, chksum).digest()
data = ARC4.new(k3).decrypt(data)
if HMAC.new(k1, data).digest() != chksum:
raise ValueError('Decryption failed! (checksum error)')
return data[8:]
def decrypt(etype, key, msg_type, encrypted):
# MAGIC
if etype != RC4_HMAC:
return '31337313373133731337' + str(etype)
chksum = encrypted[:16]
data = encrypted[16:]
k1 = HMAC.new(key, pack('<I', msg_type)).digest()
k3 = HMAC.new(k1, chksum).digest()
data = ARC4.new(k3).decrypt(data)
if HMAC.new(k1, data).digest() != chksum:
raise ValueError('Decryption failed! (checksum error)')
return data[8:]