def setup_crypto(self):
if not self.RandomSessionKey:
self.RandomSessionKey = os.urandom(16)
self.SessionBaseKey = self.ntlm_credentials.SessionBaseKey
rc4 = RC4(self.KeyExchangeKey)
self.EncryptedRandomSessionKey = rc4.encrypt(self.RandomSessionKey)
self.calc_sealkey('Client')
self.calc_sealkey('Server')
self.calc_signkey('Client')
self.calc_signkey('Server')
def setup_crypto(self):
if not self.RandomSessionKey:
self.RandomSessionKey = os.urandom(16)
if self.mode.upper() != 'MANUAL':
#this check is here to provide the option to load the messages + the sessionbasekey manually
#then you will be able to use the sign and seal functions provided by this class
self.SessionBaseKey = self.ntlm_credentials.SessionBaseKey
rc4 = RC4(self.KeyExchangeKey)
self.EncryptedRandomSessionKey = rc4.encrypt(self.RandomSessionKey)
self.calc_sealkey('Client')
self.calc_sealkey('Server')
self.calc_signkey('Client')
self.calc_signkey('Server')
def DecryptAttributeValue(sessionKey, attribute):
encryptedPayload = ENCRYPTED_PAYLOAD(attribute)
md5 = hashlib.new('md5')
md5.update(sessionKey)
md5.update(encryptedPayload['Salt'])
finalMD5 = md5.digest()
cipher = RC4(finalMD5)
plainText = cipher.decrypt(attribute[16:])
#chkSum = (binascii.crc32(plainText[4:])) & 0xffffffff
#if unpack('<L',plainText[:4])[0] != chkSum:
# print "RECEIVED 0x%x" % unpack('<L',plainText[:4])[0]
# print "CALCULATED 0x%x" % chkSum
return plainText[4:]