des.py 文件源码

def decryptData(self, decryptKey, privParameters, encryptedData):
        if DES is None:
            raise error.StatusInformation(
                errorIndication=errind.decryptionError
            )

        snmpEngineBoots, snmpEngineTime, salt = privParameters

        # 8.3.2.1
        if len(salt) != 8:
            raise error.StatusInformation(
                errorIndication=errind.decryptionError
            )

        # 8.3.2.2 noop

        # 8.3.2.3
        desKey, iv = self.__getDecryptionKey(decryptKey, salt)

        # 8.3.2.4 -> 8.1.1.3
        if len(encryptedData) % 8 != 0:
            raise error.StatusInformation(
                errorIndication=errind.decryptionError
            )

        desObj = DES.new(desKey, DES.MODE_CBC, iv)

        # 8.3.2.6
        return desObj.decrypt(encryptedData.asOctets())