------ Credits to Anavrins for SHA-256 in LUA API (Without him this = impossible)
--- Please rush down this is just SHA-256 code
local mod32 = 2^32
local sha_hashlen = 32
local sha_blocksize = 64

local band    = bit32 and bit32.band or bit.band
local bnot    = bit32 and bit32.bnot or bit.bnot
local bxor    = bit32 and bit32.bxor or bit.bxor
local blshift = bit32 and bit32.lshift or bit.blshift
local upack   = unpack

local function rrotate(n, b)
  local s = n/(2^b)
  local f = s%1
  return (s-f) + f*mod32
end
local function brshift(int, by) -- Thanks bit32 for bad rshift
  local s = int / (2^by)
  return s - s%1
end

local H = {
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
}

local K = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
}

local function incr(t, incr)
  if 0xFFFFFFFF - t[1] < incr then
    t[2] = t[2] + 1
    t[1] = incr - (0xFFFFFFFF - t[1]) - 1   
    else t[1] = t[1] + incr
    end
    return t
  end

  local function preprocess(data)
   local len = #data

   data[#data+1] = 0x80
   while #data%64~=56 do data[#data+1] = 0 end
   local l = incr({0,0}, len*8)
   for i = 2, 1, -1 do
    data[#data+1] = band(brshift(band(l[i], 0xFF000000), 24), 0xFF)
    data[#data+1] = band(brshift(band(l[i], 0xFF0000), 16), 0xFF)
    data[#data+1] = band(brshift(band(l[i], 0xFF00), 8), 0xFF)
    data[#data+1] = band(l[i], 0xFF)
  end
  return data
end

local function BE_toInt(bs, i)
  return blshift((bs[i] or 0), 24) + blshift((bs[i+1] or 0), 16) + blshift((bs[i+2] or 0), 8) + (bs[i+3] or 0)
end

local function digestblock(data, i, C)
  local w = {}
  for j = 1, 16 do w[j] = BE_toInt(data, i+(j-1)*4) end
  for j = 17, 64 do
    local v = w[j-15]
    local s0 = bxor(bxor(rrotate(w[j-15], 7), rrotate(w[j-15], 18)), brshift(w[j-15], 3))
    local s1 = bxor(bxor(rrotate(w[j-2], 17), rrotate(w[j-2], 19)), brshift(w[j-2], 10))
    w[j] = (w[j-16] + s0 + w[j-7] + s1)%mod32
  end
  local a, b, c, d, e, f, g, h = upack(C)
  for j = 1, 64 do
    local S1 = bxor(bxor(rrotate(e, 6), rrotate(e, 11)), rrotate(e, 25))
    local ch = bxor(band(e, f), band(bnot(e), g))
    local temp1 = (h + S1 + ch + K[j] + w[j])%mod32
    local S0 = bxor(bxor(rrotate(a, 2), rrotate(a, 13)), rrotate(a, 22))
    local maj = bxor(bxor(band(a, b), band(a, c)), band(b, c))
    local temp2 = (S0 + maj)%mod32
    h, g, f, e, d, c, b, a = g, f, e, (d+temp1)%mod32, c, b, a, (temp1+temp2)%mod32
  end
  C[1] = (C[1] + a)%mod32
  C[2] = (C[2] + b)%mod32
  C[3] = (C[3] + c)%mod32
  C[4] = (C[4] + d)%mod32
  C[5] = (C[5] + e)%mod32
  C[6] = (C[6] + f)%mod32
  C[7] = (C[7] + g)%mod32
  C[8] = (C[8] + h)%mod32
  return C
end

local mt = {
__tostring = function(a) return string.char(unpack(a)) end,
__index = {
toHex = function(self, s) return ("%02x"):rep(#self):format(unpack(self)) end,
isEqual = function(self, t)
 if type(t) ~= "table" then return false end
 if #self ~= #t then return false end
 local ret = 0
 for i = 1, #self do
  ret = bit32.bor(ret, bxor(self[i], t[i]))
end
return ret == 0
end
}
}

local function toBytes(t, n)
  local b = {}
  for i = 1, n do
    b[(i-1)*4+1] = band(brshift(band(t[i], 0xFF000000), 24), 0xFF)
    b[(i-1)*4+2] = band(brshift(band(t[i], 0xFF0000), 16), 0xFF)
    b[(i-1)*4+3] = band(brshift(band(t[i], 0xFF00), 8), 0xFF)
    b[(i-1)*4+4] = band(t[i], 0xFF)
  end
  return setmetatable(b, mt)
end

function digest(data)
  data = data or ""
  data = type(data) == "string" and {data:byte(1,-1)} or data

  data = preprocess(data)
  local C = {upack(H)}
  for i = 1, #data, 64 do C = digestblock(data, i, C) end
  return toBytes(C, 8)
end

function hmac(data, key)
  local data = type(data) == "table" and {upack(data)} or {tostring(data):byte(1,-1)}
  local key = type(key) == "table" and {upack(key)} or {tostring(key):byte(1,-1)}

  local blocksize = sha_blocksize

  key = #key > blocksize and digest(key) or key

  local ipad = {}
  local opad = {}
  local padded_key = {}

  for i = 1, blocksize do
    ipad[i] = bxor(0x36, key[i] or 0)
    opad[i] = bxor(0x5C, key[i] or 0)
  end

  for i = 1, #data do
    ipad[blocksize+i] = data[i]
  end

  ipad = digest(ipad)

  for i = 1, blocksize do
    padded_key[i] = opad[i]
    padded_key[blocksize+i] = ipad[i]
  end

  return digest(padded_key)
end

function pbkdf2(pass, salt, iter, dklen)
  local out = {}
  local hashlen = sha_hashlen
  local block = 1
  dklen = dklen or 32

  while dklen > 0 do
    local ikey = {}
    local isalt = type(salt) == "table" and {upack(salt)} or {tostring(salt):byte(1,-1)}
    local clen = dklen > hashlen and hashlen or dklen

    isalt[#isalt+1] = band(brshift(band(block, 0xFF000000), 24), 0xFF)
    isalt[#isalt+1] = band(brshift(band(block, 0xFF0000), 16), 0xFF)
    isalt[#isalt+1] = band(brshift(band(block, 0xFF00), 8), 0xFF)
    isalt[#isalt+1] = band(block, 0xFF)

    for j = 1, iter do
      isalt = hmac(isalt, pass)
      for k = 1, clen do ikey[k] = bxor(isalt[k], ikey[k] or 0) end
      if j % 200 == 0 then os.queueEvent("PBKDF2", j) coroutine.yield("PBKDF2") end
    end
    dklen = dklen - clen
    block = block+1
    for k = 1, clen do out[#out+1] = ikey[k] end
  end

  return setmetatable(out, mt)
end
--[[----------------------------------------------------------
                 Main Functions Begin
                  SHA-256 Code END
-----------------------------------------------------------]]--
token = "def_tk_010sk25jsmiq25jgsm23915asddrasdf" -- If you edit this, remember it and edit this in your disk lost password too! else u wont be able to ever recover password.
function encrypt(str, saltt)
  return pbkdf2(str, saltt, 128):toHex()
end
oldPullEvent = os.pullEvent
os.pullEvent = os.pullEventRaw
function CheckInstallation()
  print("NOTE: Disk's must be the first one attached")
  sleep(0.5)
  if not fs.exists("DiskLock.shx") then
    term.clear()
    term.setCursorPos(1,1)
    print("Do you want to create a computer lock?") 
    print("Valid Values: yes/no (Case-Sensitive)")
    val = read()
    if val == "yes" then
      term.clear()
      term.setCursorPos(1, 1)
      if not fs.exists("/disk/") then
        oldCol = term.getTextColor()
        if term.isColor() then 
          term.setTextColor(colors.blue) 
        end 
        print("Please insert your disk, After press enter to continue")
        if term.isColor() then 
          term.setTextColor(colors.black) 
        end
        entr = read("")
        if term.isColor() then 
          term.setTextColor(oldCol) 
        end
        CheckInstallation()
      else
        oldCol = term.getTextColor()
        if term.isColor() then 
          term.setTextColor(colors.lightBlue) 
        end
        print("Found Disc Continuing...")
        if term.isColor() then 
          term.setTextColor(oldCol) 
        end
        sleep(0.3)
        term.clear()
        term.setCursorPos(1, 1)
        oldCol = term.getTextColor()
        if term.isColor() then 
          term.setTextColor(colors.orange)
        end
        print("Please insert your desired password!")
        print("<!> Remember this since it can create your another password disk!")
        if term.isColor() then 
          term.setTextColor(colors.green) 
        end
        pass = read("*")
        if term.isColor() 
          then term.setTextColor(oldCol) 
        end
        if pass == nil or pass == "" or pass == " " or pass == "123" or pass == "abc" then
          sleep(1.0)
          term.clear()
          term.setCursorPos(1, 1)
          oldCol = term.getTextColor()
          if term.isColor() then 
            term.setTextColor(colors.red) 
          end
          print("Its a dumb password!")
          if term.isColor() then 
            term.setTextColor(oldCol) 
          end
          error() 
        else
          handle = fs.open("DiskLock.shx", "w")
          compId = os.computerID()
          idwpass = compId ..":" ..token
          term.clear()
          if term.isColor() then 
            oco2 = term.getTextColor()
            term.setTextColor(colors.yellow) 
          end
          print("Encrypting Now, It will take some time but you will get better results too!")
          if term.isColor() then 
            term.setTextColor(oco2)
          end
          enc_pass = encrypt(pass, idwpass)
          handle.write(enc_pass)
          handle.close()
          if fs.exists("disk/DiskLock.shc") then
            fs.delete("disk/DiskLock.shc")
          end
          handle = fs.open("disk/DiskLock.shc", "w")
          handle.write(enc_pass)
          handle.close()
          shell.run("set shell.allow_disk_startup false")
          term.clear()
          term.setCursorPos(1, 1)
          oldCol = term.getTextColor()
          if term.isColor() then 
            term.setTextColor(colors.green) 
          end
          print("<!> " ..tostring(compId) .. " is your computer id, Remember it to recover password disk")
          sleep(5)
          term.clear()
          print("Success, Rebooting now to apply changes...")
          if term.isColor() then 
            term.setTextColor(oldCol) 
          end
          sleep(1)
          os.reboot()
        end
      end
    elseif val == "no" then
      term.clear()
      term.setCursorPos(1, 1)
      oldCol = term.getTextColor()
      if term.isColor() then 
        term.setTextColor(colors.red) 
      end
      print("You chose NO, Continuing to Boot")
      if term.isColor() then 
        term.setTextColor(oldCol) 
      end
      error()
    else
      term.clear()
      term.setCursorPos(1, 1)
      oldCol = term.getTextColor()
      if term.isColor() then 
        term.setTextColor(colors.blue) 
      end
      print("Unknown/Idiotic Value...")
      if term.isColor() then 
        term.setTextColor(oldCol) 
      end
      error() 
    end
  end
end
function CheckLogin()
  term.clear()
  term.setCursorPos(1,1)
  if fs.exists("DiskLock.shx") then
    shell.run("set shell.allow_disk_startup false")
    term.clear()
    term.setCursorPos(1, 1)
    if not fs.exists("/disk/") then
      term.clear()
      oldCol = term.getTextColor()
      if term.isColor() then 
        term.setTextColor(colors.red) 
      end
      print("Welcome, Please insert the login disk!")
      if term.isColor() then 
        term.setTextColor(colors.yellow) 
      end
      print("Press enter once done.")
      if term.isColor() then 
        term.setTextColor(colors.black) 
      end
      xazz = read("")
      if term.isColor() then 
        term.setTextColor(oldCol) 
      end
      CheckLogin()
    else
      oldCol = term.getTextColor()
      if term.isColor() then 
        term.setTextColor(colors.orange) end
        print("Reading Disk.....")
        if term.isColor() then 
          term.setTextColor(oldCol) 
        end
        sleep(1)
        if not fs.exists("disk/DiskLock.shc") then
          oldCol = term.getTextColor()
          if term.isColor() then 
            term.setTextColor(colors.red) 
          end
          print("This disk does not contain login files!")
          if term.isColor() then 
            term.setTextColor(oldCol) 
          end
          sleep(1)
          CheckLogin()
        else
          pathTofile = shell.resolve("disk/DiskLock.shc")
          file = fs.open(pathTofile, "r")
          if file then
            diskdata = file.readAll()
            file.close()
            p2f2 = shell.resolve("DiskLock.shx")
            file2 = fs.open(p2f2, "r")
            if not file2 then
             oldCol = term.getTextColor()
             if term.isColor() then 
              term.setTextColor(colors.red) 
            end 
            print("Computer failed to read the login data, File.IO Failure!")
            print("Computer has not continued to boot.")
            if term.isColor() then 
              term.setTextColor(oldCol) 
            end 
          end
          logindata = file2.readAll()
          file2.close()
          if (diskdata == logindata) then
            oldCol = term.getTextColor()
            if term.isColor() then 
              term.setTextColor(colors.red) 
            end 
 			shell.run("eject", "left")
			shell.run("eject", "right")
			shell.run("eject", "top")
			shell.run("eject", "bottom")
			term.clear()
            oldCol = term.getTextColor()
            if term.isColor() then
			    term.setTextColor(colors.green)
            end
            print("Welcome back!")
            if term.isColor() then 
              term.setTextColor(oldCol)
            end
            os.pullEvent = oldPullEvent
            error()
          else
            oldCol = term.getTextColor()
            if term.isColor() then 
              term.setTextColor(colors.red) 
            end
            print("The login data dosen't match!")
            if term.isColor() then 
              term.setTextColor(oldCol) 
            end
            sleep(1)
            CheckLogin()
          end
        else
         oldCol = term.getTextColor()
         if term.isColor() then 
          term.setTextColor(colors.red) 
        end
        print("Failed to read the disk file!")
        if term.isColor() then 
          term.setTextColor(oldCol) 
        end
        sleep(1)
        CheckLogin()
      end
    end
  end
end
end
CheckInstallation()
CheckLogin()