security start

apps/trust.lua

@@ -1,6 +1,8 @@
 require = requireInjector(getfenv(1))
 local Socket = require('socket')
 local SHA1 = require('sha1')
+local Terminal = require('terminal')
+local Crypto = require('crypto')
 
 local remoteId
 local args = { ... }
@@ -21,7 +23,11 @@ if not remoteId then
 end
 
 print('Password')
-local password = read()
+local password = Terminal.readPassword('Enter password: ')
+
+if not password then
+  error('Invalid password')
+end
 
 print('connecting...')
 local socket = Socket.connect(remoteId, 19)
@@ -45,11 +51,9 @@ end
 
 local secretKey = os.getSecretKey()
 local publicKey = modexp(exchange.base, secretKey, exchange.primeMod)
+local password = SHA1.sha1(password)
 
-socket:write({
-  password = SHA1.sha1(password),
-  publicKey = publicKey,
-})
+socket:write(Crypto.encrypt({ pk = publicKey }, password))
 
 print(socket:read(2) or 'No response')
 

sys/apis/crypto.lua

@@ -0,0 +1,151 @@
+-- https://github.com/PixelToast/ComputerCraft/blob/master/apis/enc
+
+local Crypto = { }
+
+local function serialize(t) 
+  local sType = type(t)
+  if sType == "table" then
+    local lstcnt=0
+    for k,v in pairs(t) do
+      lstcnt = lstcnt + 1
+    end
+    local result = "{"
+    local aset=1
+    for k,v in pairs(t) do
+      if k==aset then
+        result = result..serialize(v)..","
+        aset=aset+1
+      else
+        result = result..("["..serialize(k).."]="..serialize(v)..",")
+      end
+    end
+    result = result.."}"
+    return result
+  elseif sType == "string" then
+    return string.format("%q",t)
+  elseif sType == "number" or sType == "boolean" or sType == "nil" then
+    return tostring(t)
+  elseif sType == "function" then
+    local status,data=pcall(string.dump,t)
+    if status then
+      data2=""
+      for char in string.gmatch(data,".") do
+        data2=data2..zfill(string.byte(char))
+      end
+      return 'f("'..data2..'")'
+    else
+      error("Invalid function: "..data)
+    end
+  else
+    error("Could not serialize type "..sType..".")
+  end
+end
+
+local function unserialize( s )
+  local func, e = loadstring( "return "..s, "serialize" )
+  if not func then
+    return s,e
+  else
+    setfenv( func, {
+      f=function(S)
+        return loadstring(splitnum(S))
+      end,
+    })
+    return func()
+  end
+end
+
+local function sure(N,n)
+  if (l2-n)<1 then N="0" end
+  return N
+end
+
+local function splitnum(S)
+  Out=""
+  for l1=1,#S,2 do
+    l2=(#S-l1)+1
+    CNum=tonumber("0x"..sure(string.sub(S,l2-1,l2-1),1) .. sure(string.sub(S,l2,l2),0))
+    Out=string.char(CNum)..Out
+  end
+  return Out
+end
+
+local function zfill(N)
+  N=string.format("%X",N)
+  Zs=""
+  if #N==1 then
+    Zs="0"
+  end
+  return Zs..N
+end
+
+local function wrap(N)
+  return N-(math.floor(N/256)*256)
+end
+
+local function checksum(S)
+  local sum=0
+  for char in string.gmatch(S,".") do
+    math.randomseed(string.byte(char)+sum)
+    sum=sum+math.random(0,9999)
+  end
+  math.randomseed(sum)
+  return sum
+end
+
+local function genkey(len,psw)
+  checksum(psw)
+  local key={}
+  local tKeys={}
+  for l1=1,len do
+    local num=math.random(1,len)
+    while tKeys[num] do
+      num=math.random(1,len)
+    end
+    tKeys[num]=true
+    key[l1]={num,math.random(0,255)}
+  end
+  return key
+end
+
+function Crypto.encrypt(data,psw)
+  data=serialize(data)
+  local chs=checksum(data)
+  local key=genkey(#data,psw)
+  local out={}
+  local cnt=1
+  for char in string.gmatch(data,".") do
+    table.insert(out,key[cnt][1],zfill(wrap(string.byte(char)+key[cnt][2])),chars)
+    cnt=cnt+1
+  end
+  return string.sub(serialize({chs,table.concat(out)}),2,-3)
+end
+
+function Crypto.decrypt(data,psw)
+  local oData=data
+  data=unserialize("{"..data.."}")
+  if type(data)~="table" then
+    return oData
+  end
+  local chs=data[1]
+  data=data[2]
+  local key=genkey((#data)/2,psw)
+  local sKey={}
+  for k,v in pairs(key) do
+    sKey[v[1]]={k,v[2]}
+  end
+  local str=splitnum(data)
+  local cnt=1
+  local out={}
+  for char in string.gmatch(str,".") do
+    table.insert(out,sKey[cnt][1],string.char(wrap(string.byte(char)-sKey[cnt][2])))
+    cnt=cnt+1
+  end
+  out=table.concat(out)
+  if checksum(out or "")==chs then
+    return unserialize(out)
+  end
+  return oData,out,chs
+end
+
+return Crypto

sys/apis/socket.lua

@@ -1,4 +1,5 @@
 local Logger = require('logger')
+local Crypto = require('crypto')
 
 local socketClass = { }
 
@@ -168,7 +169,7 @@ function Socket.connect(host, port)
     type = 'OPEN',
     shost = socket.shost,
     dhost = socket.dhost,
-    sharedKey = exchange.publicKey,
+    t = Crypto.encrypt({ ts = os.time() }, exchange.publicKey),
   })
 
   local timerId = os.startTimer(3)
@@ -206,8 +207,10 @@ function trusted(msg, port)
   local pubKey = trustList[msg.shost]
 
   if pubKey then
+    local data = Crypto.decrypt(msg.t or '', pubKey)
+
     --local sharedKey = modexp(pubKey, exchange.secretKey, public.primeMod)
-    return pubKey == msg.sharedKey
+    return data.ts and tonumber(data.ts) and math.abs(os.time() - data.ts) < 1
   end
 end
 

sys/apis/terminal.lua

@@ -150,4 +150,19 @@ function Terminal.mirror(ct, dt)
   end
 end
 
+function Terminal.readPassword(prompt)
+  if prompt then
+    term.write(prompt)
+  end
+  local fn = term.write
+  term.write = function() end
+  local s = read(prompt)
+  term.write = fn
+
+  if s == '' then
+    return
+  end
+  return s
+end
+
 return Terminal

sys/extensions/os.lua

@@ -67,6 +67,11 @@ function os.getSecretKey()
   return Util.readFile('.secret')
 end
 
+function os.getPassword()
+  Config.load('os', config)
+  return config.password
+end
+
 os.lock = function()
   --os.locked = true
 

sys/network/trust.lua

@@ -1,5 +1,6 @@
 local Socket = require('socket')
 local process = require('process')
+local Crypto = require('crypto')
 
 process:newThread('trust_server', function()
 
@@ -11,9 +12,14 @@ process:newThread('trust_server', function()
 
     local data = socket:read(2)
     if data then
-      if os.verifyPassword(data.password) then
+      local password = os.getPassword()
+      if not password then
+        socket:write('No password has been set')
+      else
+        data = Crypto.decrypt(data, password)
+        if data and data.pk then
           local trustList = Util.readTable('.known_hosts') or { }
-        trustList[socket.dhost] = data.publicKey
+          trustList[socket.dhost] = data.pk
           Util.writeTable('.known_hosts', trustList)
 
           socket:write('Trust accepted')
@@ -21,6 +27,7 @@ process:newThread('trust_server', function()
           socket:write('Invalid password or password is not set')
         end
       end
+    end
     socket:close()
   end
 end)