Method encrypt

scapy/layers/smb2.py:2001–2039

[MS-SMB2] sect 3.1.4.3 - Encrypting the Message

(self, dialect, EncryptionKey, CipherId)

            raise Exception("ERROR: SMB signature is invalid !")

    def encrypt(self, dialect, EncryptionKey, CipherId):
        """
        [MS-SMB2] sect 3.1.4.3 - Encrypting the Message
        """
        if dialect < 0x0300:
            raise Exception("Encryption is not supported on this SMB dialect !")
        elif dialect < 0x0311 and CipherId != "AES-128-CCM":
            raise Exception("CipherId is not supported on this SMB dialect !")

        data = bytes(self)
        smbt = SMB2_Transform_Header(
            OriginalMessageSize=len(self),
            SessionId=self.SessionId,
            Flags=0x0001,
        )
        if "GCM" in CipherId:
            from cryptography.hazmat.primitives.ciphers.aead import AESGCM

            nonce = os.urandom(12)
            cipher = AESGCM(EncryptionKey)
        elif "CCM" in CipherId:
            from cryptography.hazmat.primitives.ciphers.aead import AESCCM

            nonce = os.urandom(11)
            cipher = AESCCM(EncryptionKey)
        else:
            raise Exception("Unknown CipherId !")

        # Add nonce to header and build the auth data
        smbt.Nonce = nonce
        aad = bytes(smbt)[20:]

        # Perform the actual encryption
        data = cipher.encrypt(nonce, data, aad)

        # Put the auth tag in the Signature field
        smbt.Signature, data = data[-16:], data[:-16]

        return smbt / data


class _SMB2_Payload(Packet):