def DESL(K, D):
"""
Indicates the encryption of an 8-byte data item D with the 16-byte key K
using the Data Encryption Standard Long (DESL) algorithm.
The result is 24 bytes in length.
:param K:
:param D:
:return:
"""
if len(K) != 16:
raise Exception("K MUST be 16 bytes long")
if len(D) != 8:
raise Exception("D MUST be 8 bytes long")
res = b''
res += DES(K[:7]).encrypt(D)
res += DES(K[7:14]).encrypt(D)
res += DES(K[14:] + b'\x00' * 5).encrypt(D)
return res
def calc_key_exchange_key(self, with_lm = False, non_nt_session_key = False): if self.credentials.password: lm_hash = LMOWFv1(self.credentials.password) else: lm_hash = self.credentials.lm_hash if with_lm: temp1 = DES(lm_hash[:7]).encrypt(self.LMResponse.to_bytes()[:8]) temp2 = DES(lm_hash[7:8] + b'\xBD\xBD\xBD\xBD\xBD\xBD').encrypt(self.LMResponse.to_bytes()[:8]) kex = temp1 + temp2 else: if non_nt_session_key: kex = lm_hash[:8] + b'\x00' * 8 else: kex = self.SessionBaseKey return kex
def LMOWFv1(password):
LM_SECRET = b'KGS!@#$%'
t1 = password[:14].ljust(14, '\x00').upper()
d = DES(t1[:7].encode('ascii'))
r1 = d.encrypt(LM_SECRET)
d = DES(t1[7:].encode('ascii'))
r2 = d.encrypt(LM_SECRET)
return r1 + r2
def removeDESLayer(cryptedHash, rid): Key1,Key2 = deriveKey(rid) Crypt1 = DES(Key1, cipherMODE.ECB) Crypt2 = DES(Key2, cipherMODE.ECB) decryptedHash = Crypt1.decrypt(cryptedHash[:8]) + Crypt2.decrypt(cryptedHash[8:]) return decryptedHash