My Hawaii Vacation Lua Decode

hawaii_decode.lua

#!/usr/bin/env lua

-- Placeholder for the actual key
local __K = "YOUR_12K_CHARACTER_KEY_HERE"

-- Helper function to create UTF-8 character from bytes
local function __U8(a, b, c, d)
  return string.char(a, b, c, d)
end

-- Create the 16-token alphabet (hex nibbles 0-F)
local function __T()
  return {
    __U8(240, 159, 140, 186),  -- 0
    __U8(240, 159, 140, 180),  -- 1
    __U8(240, 159, 140, 138),  -- 2
    __U8(240, 159, 140, 139),  -- 3
    __U8(240, 159, 165, 165),  -- 4
    __U8(240, 159, 140, 136),  -- 5
    __U8(240, 159, 144, 162),  -- 6
    __U8(240, 159, 144, 160),  -- 7
    __U8(240, 159, 144, 172),  -- 8
    __U8(240, 159, 144, 139),  -- 9
    __U8(240, 159, 144, 154),  -- A
    __U8(240, 159, 144, 179),  -- B
    __U8(240, 159, 144, 161),  -- C
    __U8(240, 159, 166, 128),  -- D
    __U8(240, 159, 166, 136),  -- E
    __U8(240, 159, 144, 153)   -- F
  }
end

-- Simple hash function for key
local function S(k)
  k = tostring(k or "")
  local s = 3237919422
  for i = 1, #k do
    s = (s * 1315423911 + k:byte(i)) % 4294967296
  end
  return s
end

-- Linear congruential generator for keystream
local function M(seed)
  return function()
    seed = (1664525 * seed + 1013904223) % 4294967296
    return seed
  end
end

-- 4-bit XOR function
local function X(a, b)
  local r, p = 0, 1
  for _ = 1, 4 do
    local A = a % 2
    local B = b % 2
    if (A + B) % 2 == 1 then
      r = r + p
    end
    a = (a - A) / 2
    b = (b - B) / 2
    p = p * 2
  end
  return r
end

-- Main decoder function
local function __D(t, k)
  local T = __T()
  local toklen = 4
  
  if k == nil then
    k = __K
  end
  
  local key_on = k ~= nil and k ~= ""
  local permute = true and key_on
  
  -- Build permutation table
  local perm = {}
  for n = 0, 15 do
    perm[n] = n
  end
  
  if permute then
    local r = M(S(tostring(k) .. "|perm"))
    for i = 15, 1, -1 do
      local j = r() % (i + 1)
      perm[i], perm[j] = perm[j], perm[i]
    end
  end
  
  -- Build decode map
  local dec_map = {}
  for n = 0, 15 do
    local idx = permute and perm[n] or n
    dec_map[T[idx + 1]] = n
  end
  
  -- Remove whitespace from input
  t = (t or ""):gsub("%s+", "")
  
  local out, n, i, step = {}, #t, 1, toklen * 2
  
  -- Setup keystream for XOR
  local ks
  if key_on then
    local r = M(S(tostring(k) .. "|xor"))
    function ks()
      local v = r() % 256
      return (v - v % 16) / 16, v % 16
    end
  end
  
  -- Decode pairs of tokens
  while n >= i + step - 1 do
    local a = t:sub(i, i + toklen - 1)
    local b = t:sub(i + toklen, i + step - 1)
    local hi, lo = dec_map[a], dec_map[b]
    
    if not hi or not lo then
      break
    end
    
    if ks then
      local kh, kl = ks()
      hi = X(hi, kh)
      lo = X(lo, kl)
    end
    
    out[#out + 1] = string.char(hi * 16 + lo)
    i = i + step
  end
  
  return table.concat(out)
end

-- Convert escaped string to actual bytes
local function unescape_string(s)
  -- Convert \240\159\140\186 style escapes to actual characters
  return s:gsub("\\(%d%d%d)", function(d)
    return string.char(tonumber(d))
  end)
end

-- Test function to decode all strings in a file
local function decode_all_strings(filename)
  local f = io.open(filename, "r")
  if not f then
    print("Error: Cannot open file " .. filename)
    return
  end
  
  local content = f:read("*all")
  f:close()
  
  -- Pattern to match __D("...", __K) or __D('...', __K) calls
  -- This captures the escaped string content
  local results = {}
  local count = 0
  
  -- Match both single and double quoted strings
  for encoded in content:gmatch('__D%("([^"]+)", __K%)') do
    count = count + 1
    local unescaped = unescape_string(encoded)
    local decoded = __D(unescaped, __K)
    if decoded and #decoded > 0 then
      -- Try to show first 40 chars of encoded for reference
      local preview = encoded:sub(1, 40)
      if #encoded > 40 then preview = preview .. "..." end
      table.insert(results, {
        num = count,
        encoded = preview,
        decoded = decoded
      })
    end
  end
  
  for encoded in content:gmatch("__D%('([^']+)', __K%)") do
    count = count + 1
    local unescaped = unescape_string(encoded)
    local decoded = __D(unescaped, __K)
    if decoded and #decoded > 0 then
      local preview = encoded:sub(1, 40)
      if #encoded > 40 then preview = preview .. "..." end
      table.insert(results, {
        num = count,
        encoded = preview,
        decoded = decoded
      })
    end
  end
  
  return results
end

-- Main execution
if arg[1] == "test" then
  -- Test with specific encoded string (with escape sequences)
  local encoded = arg[2]
  if encoded then
    local unescaped = unescape_string(encoded)
    print("Decoded: " .. __D(unescaped, __K))
  else
    print("Usage: lua decoder.lua test <encoded_string>")
  end
elseif arg[1] == "file" then
  -- Decode all strings from file
  local filename = arg[2] or "decompiled.lua"
  print("Decoding strings from: " .. filename)
  print(string.rep("=", 70))
  
  local results = decode_all_strings(filename)
  
  if #results == 0 then
    print("WARNING: No strings found!")
    print("\nDebugging: Checking if key is set...")
    if __K == "YOUR_12K_CHARACTER_KEY_HERE" then
      print("ERROR: You need to replace __K with the actual key!")
    else
      print("Key is set (length: " .. #__K .. ")")
      print("\nTrying to decode a test string...")
      -- Try decoding one of the constants we can see
      local test = unescape_string("\\240\\159\\140\\138\\240\\159\\144\\172")
      print("Test decode result: [" .. __D(test, __K) .. "]")
    end
  else
    for i, result in ipairs(results) do
      print(string.format("%3d. %s", result.num, result.decoded))
      print("     Encoded: " .. result.encoded)
      print()
    end
  end
  
  print(string.rep("=", 70))
  print("Total strings decoded: " .. #results)
else
  -- Interactive mode
  print("Prometheus String Decoder")
  print("Usage:")
  print("  lua decoder.lua test <encoded_string>  - Decode single string")
  print("  lua decoder.lua file [filename]        - Decode all strings from file")
  print()
  if __K == "YOUR_12K_CHARACTER_KEY_HERE" then
    print("WARNING: Key not set! Replace __K with actual key")
  else
    print("Key length: " .. #__K .. " characters")
  end
end

-- Export the decoder function for use as module
return {
  decode = __D,
  decode_all = decode_all_strings
}