Merge pull request #2959 from trigat/master

Add ntag_clean Lua file via upload

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+- Added `ntag_clean.lua` script for easier NTAG memory wipe (@trigat)
 - Changed from Bigbuf malloc to Bigbuf calloc calls on device side (@iceman1001)
 - Added `lf t55xx view` - now viewing of T55XX dump files is possible (@iceman1001)
 - Fixed `lf indala cone` - now writing the right bits when using `--fc` and `--cn`

client/luascripts/ntag_clean.lua

@@ -0,0 +1,142 @@
+local reader = require('read14a')
+local ansicolors  = require('ansicolors')
+
+copyright = 'Trigat'
+author = 'Trigat'
+version = 'v0.0.1'
+desc = [[
+This script zero-fills NTAG pages in a user-specified range,
+or defaults to pages 4–39.
+
+Pages 0–3 (UID and configuration) cannot be erased.
+]]
+example = [[
+    -- Zero-fill default range (pages 4–39) with 0x00
+    1. script run ntag_clean
+
+    -- Zero-fill a custom range (pages 6–10)
+    2. script run ntag_clean -s 6 -e 10
+
+    -- Fill pages 4–39 with 0xFF
+    3. script run ntag_clean -d FF
+]]
+usage = [[
+script run ntag_clean [-s <start>] [-e <end>] [-d <hex>]
+]]
+arguments = [[
+    -h             : this help
+    -s <start>     : start page (default 4)
+    -e <end>       : end page (default 39)
+    -d <hex>       : data to write (8 hex chars, e.g. 00000000)
+                     If 2 hex chars are given (e.g. FF), it repeats to 8 (FFFFFFFF).
+]]
+
+local function normalize_hex(h)
+    if not h then return nil end
+    h = h:gsub("%s+", "")
+    if not h:match("^[0-9a-fA-F]+$") then return nil end
+    if #h == 2 then
+        h = h:rep(4)   -- "FF" converted to "FFFFFFFF"
+    end
+    if #h ~= 8 then
+        return nil
+    end
+    return h:upper()
+end
+
+local function parse_args(argv)
+    local opts = {}
+    local i = 1
+    while i <= #argv do
+        local a = argv[i]
+        if a == "-h" then
+            opts.h = true
+        elseif a == "-s" then
+            opts.s = tonumber(argv[i+1]); i = i + 1
+        elseif a == "-e" then
+            opts.e = tonumber(argv[i+1]); i = i + 1
+        elseif a == "-d" then
+            opts.d = argv[i+1]; i = i + 1
+        end
+        i = i + 1
+    end
+    return opts
+end
+
+-- check if card exists
+local function card_present()
+    local tag, err = reader.read()
+    if not tag then
+        print("No card detected. Aborting.")
+        return false
+    end
+
+    print("Card detected:", tag.uid, tag.name)
+    return true
+end
+
+-- Help output
+local function help()
+    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
+
+-- convert global args string into table
+local function split_args(argstr)
+    local t = {}
+    if not argstr then return t end
+    for word in argstr:gmatch("%S+") do
+        table.insert(t, word)
+    end
+    return t
+end
+
+local function main(args)
+    local start_block = 4
+    local end_block   = 39  -- Can be modified by user
+    local data        = "00000000"
+
+    local argv = split_args(args)
+    local opts = parse_args(argv)
+
+    if opts.h then return help() end
+    if opts.s then start_block = opts.s end
+    if opts.e then end_block   = opts.e end
+    if opts.d then
+        local norm = normalize_hex(opts.d)
+        if not norm then
+            print("Invalid -d <hex>. Use 8 hex chars (e.g. 00000000) or 2 chars (e.g. FF).")
+            return
+        end
+        data = norm
+    end
+
+    if start_block < 4 then
+        print("Cannot clean page 0-3. Those are UID and Config pages.")
+        return
+    end
+    if end_block < start_block then
+        print("End block must be greater than or equal to start page.")
+        return
+    end
+
+    -- check if card is present on reader
+    if not card_present() then
+        return
+    end
+
+    print(string.format("Zero-fill (%s) to pages %d..%d", data, start_block, end_block))
+    for b = start_block, end_block do
+        core.console(string.format("hf mfu wrbl -b %d -d %s", b, data))
+    end
+    print("Done.")
+end
+
+main(args)