Merge pull request #281 from brianredbeard/lf-script

contrib: LF Programming script

diff --git a/client/scripts/lf_bulk_program.lua b/client/scripts/lf_bulk_program.lua
new file mode 100644 (file)
index 0000000..4758c20
--- /dev/null
+++ b/client/scripts/lf_bulk_program.lua
@@ -0,0 +1,158 @@
+--
+-- lf_bulk_program.lua - A tool to clone a large number of tags at once.
+-- Updated 2017-04-18
+--
+-- The getopt-functionality is loaded from pm3/client/lualibs/getopt.lua
+-- Have a look there for further details
+getopt = require('getopt')
+bit32 = require('bit32')
+
+usage = [[ script run lf_bulk_program.lua -f facility -b base_id_num -c count
+
+ e.g: 
+   script run lf_bulk_program.lua -f 1 -b 1000 -c 10
+]]
+author = "Brian Redbeard"
+desc =[[
+Perform bulk enrollment of 26 bit H10301 style RFID Tags
+For more info, check the comments in the code
+]]
+
+--[[Implement a function to simply visualize the bitstream in a text format
+--This is especially helpful for troubleshooting bitwise math issues]]--
+function toBits(num,bits)
+    -- returns a table of bits, most significant first.
+    bits = bits or math.max(1, select(2, math.frexp(num)))
+    local t = {} -- will contain the bits
+    for b = bits, 1, -1 do
+        t[b] = math.fmod(num, 2)
+        num = math.floor((num - t[b]) / 2)
+    end
+    return table.concat(t)
+end
+
+--[[Likely, I'm an idiot, but I couldn't find any parity functions in Lua
+  This can also be done with a combination of bitwise operations (in fact, 
+  is the canonically "correct" way to do it, but my brain doesn't just
+  default to this and so counting some ones is good enough for me]]--
+local function evenparity(s)
+       local _, count = string.gsub(s, "1", "")
+       
+       local p = count % 2
+       if (p == 0) then
+               return(false)
+       else
+               return(true)
+       end
+end
+       
+
+local function isempty(s)
+       return s == nil or s == ''
+end
+
+--[[The Proxmark3 "clone" functions expect the data to be in hex format so
+  take the card id number and facility ID as arguments and construct the
+  hex.  This should be easy enough to extend to non 26bit formats]]--
+local function cardHex(i,f)
+       fac = bit32.lshift(f,16)
+       id = bit32.bor(i, fac)
+       stream=toBits(id,26)
+
+       --As the function defaults to even parity and returns a boolean,
+       --perform a 'not' function to get odd parity
+       high = evenparity(string.sub(stream,0,12)) and 1 or 0
+       low = not evenparity(string.sub(stream,13)) and 1 or 0
+       bits = bit32.bor(bit32.lshift(id,1), low)
+       bits = bit32.bor(bits, bit32.lshift(high,25))
+
+       --Since the lua library bit32 is (obviously) 32 bits and we need to
+       --encode 36 bits to properly do a 26 bit tag with the preamble we need
+       --to create a higher order and lower order component which we will
+       --then assemble in the return.  The math above defines the proper
+       --encoding as per HID/Weigand/etc.  These bit flips are due to the
+       --format length check on bit 38 (cmdlfhid.c:64) and 
+       --bit 31 (cmdlfhid.c:66).
+       preamble = bit32.bor(0, bit32.lshift(1,5))
+       bits = bit32.bor(bits, bit32.lshift(1,26))
+
+       return ("%04x%08x"):format(preamble,bits)
+       
+end
+
+local function main(args)
+
+       --I really wish a better getopt function would be brought in supporting
+       --long arguments, but it seems this library was chosen for BSD style
+       --compatibility
+       for o, a in getopt.getopt(args, 'f:b:c:h') do
+               if o == 'f' then 
+                       if isempty(a) then 
+                               print("You did not supply a facility code, using 0")
+                               facility = 0
+                       else 
+                               facility = a
+                       end
+               elseif o == 'b' then 
+                       if isempty(a) then 
+                               print("You must supply the flag -b (base id)")
+                               return
+                       else
+                               baseid = a
+                       end
+               elseif o == 'c' then 
+                       if isempty(a) then 
+                               print("You must supply the flag -c (count)")
+                               return
+                       else
+                               count = a
+                       end
+               elseif o == 'h' then
+                       print(desc)
+                       print(usage)
+                       return
+               end
+       end
+
+       --Due to my earlier complaints about how this specific getopt library
+       --works, specifying ":" does not enforce supplying a value, thus we
+       --need to do these checks all over again.
+
+       if isempty(baseid) then 
+               print("You must supply the flag -b (base id)")
+               print(usage)
+               return
+       end
+
+       if isempty(count) then 
+               print("You must supply the flag -c (count)")
+               print(usage)
+               return
+       end
+
+       --If the facility ID is non specified, ensure we code it as zero
+       if isempty(facility) then 
+               print("Using 0 for the facility code as -f was not supplied")
+               facility = 0 
+       end
+
+       --The next baseid + count function presents a logic/UX conflict
+       --where users specifying -c 1 (count = 1) would try to program two
+       --tags.  This makes it so that -c 0 & -c 1 both code one tag, and all
+       --other values encode the expected amount.
+       if tonumber(count) > 0 then count = count -1 end
+
+       endid = baseid + count
+
+       for cardnum = baseid,endid do 
+               local card = cardHex(cardnum, facility)
+               print("Press enter to program card "..cardnum..":"..facility.." (hex: "..card..")")
+               --This would be better with "press any key", but we'll take
+               --what we can get.
+               io.read()
+               core.console( ('lf hid clone %s'):format(card) )
+       end
+end
+
+
+main(args)