local cmds = require('commands')
local lib14a = require('read14a')
local getopt = require('getopt')

copyright = ''
author = 'Dominic Celiano'
version = 'v1.0.1'
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.
]]
example = [[
    -- default
    script run mifareplus
]]
usage = [[
script run mifareplus -h

Arguments:
    -h             : this help
]]


-- Default
SIXTEEN_BYTES_ZEROS = '00000000000000000000000000000000'

-- ISO7816 commands used
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
local function oops(err)
    print('ERROR:', err)
    core.clearCommandBuffer()
    return nil, err
end
---
-- Usage help
local function help()
    print(copyright)
    print(author)
    print(version)
    print(desc)
    print('Example usage')
    print(example)
    print(usage)
end
---
-- Used to send raw data to the firmware to subsequently forward the data to the card.
local 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:newMIX{cmd = cmds.CMD_HF_ISO14443A_READER,
                                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 = command:sendMIX(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 > 0 then
            print(("<recvd>: %s"):format(returned_bytes)) -- need to multiply by 2 because the hex digits are actually two bytes when they are strings
            return returned_bytes
        else
            return nil
        end
    else
        oops("Error sending the card raw data.")
        return nil
    end
end

local 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

local 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

local 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

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

local 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

local 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

local function proximityCheck()
    --PreparePC--
    commandString = PREPAREPC
    response = sendRaw(commandString, true, true)
    if not response then return oops("This card is not support the proximity check command.") 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 = ''
    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 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, response)
    if #response < 20 then return oops("Wrong response length (expected 20, got "..#response..") exiting") end

    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)

    local o, a
    for o, a in getopt.getopt(args, 'h') do -- Populate command line arguments
        if o == "h" then return help() end
    end

    -- Initialize the card using the already-present read14a library
    -- Perform RATS and PPS (Protocol and Parameter Selection) check to finish the ISO 14443-4 protocol.
    info,err = lib14a.read(true, false)
    if not info then
        lib14a.disconnect()
        return oops(err)
    end

    --
    response = sendRaw("D01100", true, true)
    if not response then
        lib14a.disconnect()
        return oops("No response from PPS check")
    end

    print("Connected to")
    print(" Type : "..info.name)
    print("  UID : "..info.uid)

    -- 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)

    lib14a.disconnect()
end

main(args)
