TEE-Watchdog: Mitigating Unauthorized Activities within Trusted Execution Environments in ARM-Based Low-Power IoT Devices

Algorithm 1

Translating the application’s manifest file to memory-mapped access table

	Input:,   ⊳ CBOR-encoded Manifest File and list of system peripherals
	Output: Access Table
	procedure Policy_Converter ,
	= Decode
	3 Initialize Access Table                   ⊳ Initialize the Access Table data structure
	token = Tokenize            ⊳ Begin converting text into tokens and get first token
	while token do
	if token = = “UniqueID” then
	token = Tokenize                         ⊳ Get next token
	Access Table [i].app_ID = token
	else if token = = “Policies” then
	while 1 do
	token = Tokenize                        ⊳ Get next token
	while ti is less than sizeof (Peripherals) do
	if token = = Peripherals[ti].name then
	Access Table [i].peripheral = Peripheral[ti].addr
	token = Tokenize                      ⊳ Get next token
	if token = = “RW” then
	Access Table [i].perm = = “RW”
	++
	break
	else if token = = “RO” then
	Access Table [i].perm = = “RO”
	++
	break
	else
	++
	break                            ⊳ Invalid permission
	end
	else
	++
	end
	end
	if token has terminator then
	break
	end
	end
	else
	do nothing
	end
	end
	end procedure