FreeOpcUa / python-opcua

        self.ClientCertificate = None

        self._freeze = True

    def to_binary(self):

        packet = []

        packet.append(self.SessionId.to_binary())

        packet.append(uabin.Primitives.String.pack(self.ClientUserIdOfSession))

        packet.append(uabin.Primitives.Int32.pack(len(self.ClientUserIdHistory)))

        for fieldname in self.ClientUserIdHistory:

            packet.append(uabin.Primitives.String.pack(fieldname))

        packet.append(uabin.Primitives.String.pack(self.AuthenticationMechanism))

        packet.append(uabin.Primitives.String.pack(self.Encoding))

        packet.append(uabin.Primitives.String.pack(self.TransportProtocol))

        packet.append(uabin.Primitives.UInt32.pack(self.SecurityMode.value))

        packet.append(uabin.Primitives.String.pack(self.SecurityPolicyUri))

        packet.append(uabin.Primitives.ByteString.pack(self.ClientCertificate))

        return b''.join(packet)

    @staticmethod

    def from_binary(data):

        self.SecurityLevel = 0

        self._freeze = True

    def to_binary(self):

        packet = []

        packet.append(uabin.Primitives.String.pack(self.EndpointUrl))

        packet.append(self.Server.to_binary())

        packet.append(uabin.Primitives.ByteString.pack(self.ServerCertificate))

        packet.append(uabin.Primitives.UInt32.pack(self.SecurityMode.value))

        packet.append(uabin.Primitives.String.pack(self.SecurityPolicyUri))

        packet.append(uabin.Primitives.Int32.pack(len(self.UserIdentityTokens)))

        for fieldname in self.UserIdentityTokens:

            packet.append(fieldname.to_binary())

        packet.append(uabin.Primitives.String.pack(self.TransportProfileUri))

        packet.append(uabin.Primitives.Byte.pack(self.SecurityLevel))

        return b''.join(packet)

    @staticmethod

    def from_binary(data):