local cmds = require('commands')
local lib14a = require('read14a')
getopt = require('getopt')							-- Used to get command line arguments

example = "script run mifarePlus"
author = "Dominic Celiano"
desc =
[[
Purpose: Lua script to communicate with the Mifare Plus EV1, including personalization (setting the keys) and proximity check. Manually edit the file to add to the commands you can send the card.

Please read the NXP manual before running this script to prevent making irreversible changes. Also note:
	- The Mifare Plus must start in SL0 for personalization. Card can then be moved to SL1 or SL3.
	- The keys are hardcoded in the script to "00...". Unless you change this, only use this script for testing purposes.
	- Make sure you choose your card size correctly (2kB or 4kB).

Small changes can be to made this script to communicate with the Mifare Plus S, X, or SE.

Arguments:
	-h             : this help
]]

SIXTEEN_BYTES_ZEROS = "00000000000000000000000000000000"

GETVERS_INIT = "0360" -- Begins the GetVersion command
GETVERS_CONT = "03AF" -- Continues the GetVersion command
POWEROFF = "OFF"
WRITEPERSO = "03A8"
COMMITPERSO = "03AA"
AUTH_FIRST = "0370"
AUTH_CONT = "0372"
AUTH_NONFIRST = "0376"
PREPAREPC = "03F0"
PROXIMITYCHECK = "03F2"
VERIFYPC = "03FD"
READPLAINNOMACUNMACED = "0336"

--- 
-- This is only meant to be used when errors occur
function oops(err)
	print("ERROR: ",err)
end

---
-- Usage help
function help()
	print(desc)
	print("Example usage")
	print(example)
end

---
-- Used to send raw data to the firmware to subsequently forward the data to the card.
function sendRaw(rawdata, crc, power)
	print(("<sent>: 	  %s"):format(rawdata))

	local flags = lib14a.ISO14A_COMMAND.ISO14A_RAW
	if crc then
		flags = flags + lib14a.ISO14A_COMMAND.ISO14A_APPEND_CRC
	end
	if power then
		flags = flags + lib14a.ISO14A_COMMAND.ISO14A_NO_DISCONNECT
	end

	local command = Command:new{cmd = cmds.CMD_READER_ISO_14443a, 
								arg1 = flags, -- Send raw
								arg2 = string.len(rawdata) / 2, -- arg2 contains the length, which is half the length of the ASCII-string rawdata
								data = rawdata}
	local ignore_response = false
	local result, err = lib14a.sendToDevice(command, ignore_response)
	if result then
		--unpack the first 4 parts of the result as longs, and the last as an extremely long string to later be cut down based on arg1, the number of bytes returned
		local count,cmd,arg1,arg2,arg3,data = bin.unpack('LLLLH512',result)
		returned_bytes = string.sub(data, 1, arg1 * 2)
		if returned_bytes ~= "" then
			print(("<recvd>: %s"):format(returned_bytes)) -- need to multiply by 2 because the hex digits are actually two bytes when they are strings
		end
		return returned_bytes
	else
		err = "Error sending the card raw data."
		oops(err)
	end
end

function writePerso()
	-- Used to write any data, including the keys (Key A and Key B), for all the sectors.
	-- writePerso() command parameters:
	--		1 byte  - 0xA8 - Command Code
	--		2 bytes - Address of the first block or key to be written to (40 blocks are numbered from 0x0000 to 0x00FF)
	--		X bytes - The data bytes to be written, starting from the first block. Amount of data sent can be from 16 to 240 bytes in 16 byte increments. This allows
	--				up to 15 blocks to be written at once.
	-- response from PICC:
	--		0x90 - OK
	--		0x09 - targeted block is invalid for writes, i.e. block 0, which contains manufacturer data
	--		0x0B - command invalid
	--		0x0C - unexpected command length
	


	cardsize = 4 --need to set to 4 for 4k or 2 for 2k
	if(cardsize == 4) then
		numsectors = 39
	elseif(cardsize == 2) then
		numsectors = 31
	else
		oops("Invalid card size")
	end

	-- Write to the AES sector keys
	print("Setting AES Sector keys")
	for i=0,numsectors do --for each sector number
		local keyA_block = "40" .. string.format("%02x", i * 2)
		local keyB_block = "40" .. string.format("%02x", (i * 2) + 1)
		--Can also calculate the keys fancily to make them unique, if desired
		keyA = SIXTEEN_BYTES_ZEROS
		keyB = SIXTEEN_BYTES_ZEROS
		writeBlock(keyA_block, keyA)
		writeBlock(keyB_block, keyB)
	end
	print("Finished setting AES Sector keys")

	print("Setting misc keys which haven't been set yet.")
	--CardMasterKey
	blocknum = "9000"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--CardConfigurationKey
	blocknum = "9001"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--L3SwitchKey
	blocknum = "9003"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--SL1CardAuthKey
	blocknum = "9004"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--L3SectorSwitchKey
	blocknum = "9006"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--L1L3MixSectorSwitchKey
	blocknum = "9007"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--VC Keys
	--VCProximityKey
	blocknum = "A001"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--VCSelectENCKey
	blocknum = "A080"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--VCSelectMACKey
	blocknum = "A081"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--TransactionMACKey1
	blocknum = "C000"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	--TransactionMACConfKey1
	blocknum = "C001"
	writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
	print("Finished setting misc keys.")

	print("WritePerso finished! Card is ready to move into new security level.")
end

function writeBlock(blocknum, data)
	-- Method writes 16 bytes of the string sent (data) to the specified block number
	-- The block numbers sent to the card need to be in little endian format (i.e. block 0x0001 is sent as 0x1000)
	blocknum_little_endian = string.sub(blocknum, 3, 4) .. string.sub(blocknum, 1, 2)
	commandString = WRITEPERSO .. blocknum_little_endian .. data --Write 16 bytes (32 hex chars).
	response = sendRaw(commandString, true, true) --0x90 is returned upon success
	if string.sub(response, 3, 4) ~= "90" then
		oops(("error occurred while trying to write to block %s"):format(blocknum))
	end
end

function authenticateAES()
	-- Used to try to authenticate with the AES keys we programmed into the card, to ensure the authentication works correctly.
	commandString = AUTH_FIRST
	commandString = commandString .. ""
end

function getVersion()
	sendRaw(GETVERS_INIT, true, true)
	sendRaw(GETVERS_CONT, true, true)
	sendRaw(GETVERS_CONT, true, true)
end

function commitPerso(SL)
	--pass SL as "01" to move to SL1 or "03" to move to SL3.
	commandString = COMMITPERSO .. SL
	response = sendRaw(commandString, true, true) --0x90 is returned upon success
	if string.sub(response, 3, 4) ~= "90" then
		oops("error occurred while trying to switch security level")
	end
end

function calculateMAC(MAC_input)
	-- Pad the input if it is not a multiple of 16 bytes (32 nibbles). 
	if(string.len(MAC_input) % 32 ~= 0) then
		MAC_input = MAC_input .. "80"
	end
	while(string.len(MAC_input) % 32 ~= 0) do
		MAC_input = MAC_input .. "0"
	end
	print("Padded MAC Input = " .. MAC_input .. ", length (bytes) = " .. string.len(MAC_input) / 2)

	--The MAC would actually be calculated here, and the output stored in raw_output
	raw_output = "00010203040506070001020304050607" -- Dummy filler for now of 16-byte output. To be filled with actual MAC for testing purposes.

	-- The final 8-byte MAC output is a concatenation of every 2nd byte starting from the second MSB.
	final_output = ""
	j = 3
	for i = 1,8 do
		final_output = final_output .. string.sub(RndR, j, j + 1) .. string.sub(RndC, j, j + 1)
		j = j + 4
	end
	return final_output
end

function proximityCheck()
	--PreparePC--
	commandString = PREPAREPC
	response = sendRaw(commandString, true, true)
	if(response == "") then
		print("ERROR: This card does not support the Proximity Check command.")
		return
	end
	OPT = string.sub(response, 5, 6)
	if(tonumber(OPT) == 1) then
		pps_present = true
	else
		pps_present = false
	end
	pubRespTime = string.sub(response, 7, 10)
	if(pps_present == true) then
		pps = string.sub(response, 11, 12)
	else
		pps = nil
	end
	print("OPT = " .. OPT .. " pubRespTime = " .. pubRespTime .. " pps = " .. pps)

	--PC--
	RndC = "0001020304050607" --Random Challenge
	num_rounds = 8 --Needs to be 1, 2, 4, or 8
	part_len = 8 / num_rounds
	j = 1
	RndR = ""
	for i = 1,num_rounds do
		pRndC = ""
		for q = 1,(part_len*2) do
			pRndC = pRndC .. string.sub(RndC,j,j)
			j = j + 1
		end
		commandString = PROXIMITYCHECK .. "0" .. tostring(part_len) .. pRndC
		pRndR = string.sub(sendRaw(commandString, true, true), 3, 3+part_len)
		RndR = RndR .. pRndR
	end
	print("RndC = " .. RndC .. " RndR = " .. RndR)

	--VerifyPC--
	MAC_input = "FD" .. OPT .. pubRespTime
	if(pps_present == true) then
		MAC_input = MAC_input .. pps
	end
	rnum_concat = ""
	rnum_concat = RndR .. RndC --temporary (only works for when a single random challenge (8 bytes) is sent)
	-- j = 1
	-- for i = 1,8 do
	-- 	rnum_concat = rnum_concat .. string.sub(RndR, j, j + 1) .. string.sub(RndC, j, j + 1)
	-- 	j = j + 2
	-- end
	MAC_input = MAC_input .. rnum_concat
	print("Concatenation of random numbers = " .. rnum_concat)
	print("Final PCD concatenation before input into MAC function = " .. MAC_input)
	MAC_tag = calculateMAC(MAC_input)
	print("8-byte PCD MAC_tag (placeholder - currently incorrect) = " .. MAC_tag)
	commandString = VERIFYPC .. MAC_tag
	response = sendRaw(commandString, true, true)
	print(response)
	PICC_MAC = string.sub(response, 5, 20)
	print("8-byte MAC returned by PICC = " .. PICC_MAC)
	MAC_input = "90" .. string.sub(MAC_input, 3)
	print("Final PICC concatenation before input into MAC function = " .. MAC_input)
	MAC_tag = calculateMAC(MAC_input)
	print("8-byte PICC MAC_tag (placeholder - currently incorrect) = " .. MAC_tag)

end

---
-- The main entry point
function main(args)
	print("")								-- Print a blank line to make things look cleaner
	for o, a in getopt.getopt(args, 'h') do			-- Populate command line arguments
		if o == "h" then help() return end
	end

	-- Initialize the card using the already-present read14a library
	info,err = lib14a.read14443a(true, false)
	--Perform RATS and PPS (Protocol and Parameter Selection) check to finish the ISO 14443-4 protocol.
	response = sendRaw("e050", true, true)
	if(response == "") then
		print("No response from RATS.")
	end
	response = sendRaw("D01100", true, true)
	if(response == "") then
		print("No response from PPS check.")
	end
	if err then
		oops(err)
		sendRaw(POWEROFF, false, false)
		return
	else
		print(("Connected to card with a UID of %s."):format(info.uid))
	end


	-- Now, the card is initialized and we can do more interesting things.

	--writePerso()
	--commitPerso("03") --move to SL3
	--getVersion()
	proximityCheck()

	--commandString = VERIFYPC .. "186EFDE8DDC7D30B"
	-- MAC = f5180d6e 40fdeae8 e9dd6ac7 bcd3350b
	-- response = sendRaw(commandString, true, true)

	-- attempt to read VCProximityKey at block A001
	-- commandString = READPLAINNOMACUNMACED .. "01A0" .. "01"
	-- response = sendRaw(commandString, true, true)

	-- authenticate with CardConfigurationKey
	-- commandString = AUTH_FIRST .. "0190" .. "00"
	-- response = sendRaw(commandString, true, true)

	-- Power off the Proxmark
	sendRaw(POWEROFF, false, false)



end


main(args) -- Call the main function
