ccFTP (Rev2) [API]

--[[
    MIT License

    Copyright © 2016 Chickenbreadlp

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
]]

local ccFTPRev = "Rev2"
local runningFTPHost = nil

 -- GitHub File Downloader for Self-Suppling
local function GITget(branch, file)
    local response = http.get(
        "https://raw.githubusercontent.com/Chickenbreadlp/ReboOSt/"..branch.."/"..textutils.urlEncode( file )
    )

    if response then
        local sResponse = response.readAll()
        response.close()
        return sResponse
    else
    end
end
local function GITdownload(branch, filename, sFile)
    if fs.exists( sFile ) then
        return
    end

    local res = GITget(branch, filename)
    if res then
        local file = fs.open( sFile, "w" )
        file.write( res )
        file.close()
    end
end

 -- Pastebin Downloader for Self-Suppling
local function PASget(paste)
    local response = http.get(
        "http://pastebin.com/raw/"..textutils.urlEncode( paste )
    )

    if response then
        local sResponse = response.readAll()
        response.close()
        return sResponse
    else
    end
end
local function PASdownload(paste, sFile)
    if fs.exists( sFile ) then
        return
    end

    local res = PASget(paste)
    if res then
        local file = fs.open( sFile, "w" )
        file.write( res )
        file.close()
    end
end


 -- Way to create a keypair for AES from single case-sensitive key for Server functions
local function unfoldkeyS(keyhash)
 math.randomseed(tonumber(keyhash, 36))
 local key = {}
 local iv = {}
 for i=1, 16 do
  key[i] = math.random(0, 0xFF)
  iv[i] = math.random(0, 0xFF)
 end
 math.randomseed(os.clock())
 return key, iv
end

 -- Way to create a keypair for AES from single case-sensitive key for Clint functions
local function unfoldkeyC(Key)
 local keyhash = hash.sha256(Key)
 math.randomseed(tonumber(keyhash, 36))
 local key = {}
 local iv = {}
 for i=1, 16 do
  key[i] = math.random(0, 0xFF)
  iv[i] = math.random(0, 0xFF)
 end
 math.randomseed(os.clock())
 return key, iv
end


 -- checks if needed APIs are available and (if not) do exist
local function checkAPI()
 if ccaes == nil then
  if fs.exists("/.ccftp/ccaes") then
   os.loadAPI("/.ccftp/ccaes")
  else
   PASdownload("rCYDnCxn", "/.ccftp/ccaes")
   os.loadAPI("/.ccftp/ccaes")
  end
 end
 if hash == nil then
  if fs.exists("/.ccftp/hash") then
   os.loadAPI("/.ccftp/hash")
  else
   GITdownload("release", "ReboOSt/APIs/encryption", "/.ccftp/hash")
   os.loadAPI("/.ccftp/hash")
  end
 end
end

 -- checks for a Modem
local function checkModem()
 if rednet.isOpen() then
  return true
 end
 for _, side in ipairs( rs.getSides() ) do
  if peripheral.isPresent( side ) and peripheral.getType( side ) == "modem" then
   rednet.open( side )
   return true
  end
 end
 return false
end


 -- waits for receiving a message and unserialize it
local function waitForMessage(typ)
 local senderID = nil
 local command = nil
 if typ == "C" then
  senderID, command = rednet.receive("ccFTP", 5)
 elseif typ == "S" then
  senderID, command = rednet.receive("ccFTP")
 end
-- command = textutils.unserialize(command)
 return command, senderID
end

 -- sendMessage function for Client tools
local function sendMessageC(Hostname, UsrName, PassIV, command)
 local command = { UsrName, PassIV, command }
-- textutils.serialize(command)
 local hostID = rednet.lookup("ccFTP", Hostname)
 if hostID == nil then
  return nil
 else
  rednet.send(hostID, command, "ccFTP")
  return hostID
 end
end

 -- sendMessage function for Server tools
local function sendMessageS(response, ID)
-- command = textutils.serialize(command)
 rednet.send(ID, response, "ccFTP")
end


 -- returns the local API Rev
function getClientVer()
 return ccFTPRev
end

 -- returns the API Rev of Hostname or "nsh" if Hostname was not found
function getServerVer(Hostname)
 checkAPI()
 if checkModem() then
  local hosterID = sendMessageC(Hostname, "VerCheck", hash.sha256("VerCheck"), "VerCheck")
  if hosterID then
   local response, senderID = waitForMessage("C")
   if senderID == hosterID then
    return response
   elseif senderID == nil then
    return "nsh"
   end
  elseif hosterID == nil then
   return "nsh"
  end
 end
end


  ---- Server Functions ----

 -- returns true and current hostname if hostname is still active else it returns false
function getRunningHost()
 if runningFTPHost ~= nil then
  return true, runningFTPHost
 else
  return false
 end
end

 -- returns true if hostname was still active and is now shutdown, false if no hostname was running
function closeServer()
 if runningFTPHost ~= nil then
  rednet.unhost("ccFTP", runningFTPHost)
  runningFTPHost = nil
  return true
 else
  return false
 end
end

 -- runs a FTP Server (Hostname sets the FTP-Server Name ; FtpDir sets the Directory which should be shared through ccFTP ; UsrDir sets the directory, where the Accounts will be saved)
 -- It is not recommended to use Root Directory as FTP Share
function runServer(Hostname, loopoff, FtpDir, UsrDir)

 if Hostname == nil then
  error("Hostname missing!")
 end

 local UsrDir = UsrDir
 local FtpDir = FtpDir
 local loopoff = loopoff

 if type(loopoff) ~= "boolean" and type(loopoff) ~= "nil" then
  loopoff = false
 end

 if UsrDir == nil then UsrDir = "/.ccftp/Users" end
 if FtpDir == nil then FtpDir = "/FTP_Share" end
 if not fs.exists(FtpDir) then fs.makeDir(FtpDir) end

 checkAPI()

 if checkModem() then
  if runningFTPHost ~= Hostname and runningFTPHost ~= nil then
   closeServer()
  end
  rednet.host("ccFTP", Hostname)
  runningFTPHost = Hostname
  while true do

   local commandtab = nil
   local sender = nil
   commandtab, sender = waitForMessage("S")

   if #commandtab >= 3 then
    if commandtab[1] == "VerCheck" and commandtab[2] == hash.sha256("VerCheck") and commandtab[3] == "VerCheck" then
     sendMessageS(ccFTPRev, sender)
     if loopoff == true then
      return true, sender, "VerCheck", ""
     end
    elseif fs.exists(UsrDir.."/"..commandtab[1]) then

     local file = fs.open(UsrDir.."/"..commandtab[1], "r")
     local pass = file.readLine()
     file.close()

     local key, iv = unfoldkeyS(pass)

     if hash.sha256("iv"..iv[15]) == commandtab[2] then

      if commandtab[3][1] == "DirCont" then
       if #commandtab[3] >= 2 then
        if fs.exists(FtpDir.."/"..commandtab[3][2]) and fs.isDir(FtpDir.."/"..commandtab[3][2]) then
         local DirCont = fs.list(FtpDir.."/"..commandtab[3][2])
         local DirIdx = {}
         for _, content in ipairs(DirCont) do
          if fs.isDir(FtpDir.."/"..content) then
           table.insert(DirIdx, content)
          end
         end
         sendMessageS( { DirCont, DirIdx } , sender)
         if loopoff == true then
          return true, sender, "DirCont", commandtab[3][2]
         end
        else
         sendMessageS("ddne", sender)
         if loopoff == true then
          return false, sender, "DirCont", "ddne"
         end
        end
       else
        sendMessageS("nea", sender)
        if loopoff == true then
         return false, sender, "DirCont", "nea"
        end
       end

      elseif commandtab[3][1] == "getFile" then
       if #commandtab[3] >= 2 then
        if fs.exists(FtpDir.."/"..commandtab[3][2]) and not fs.isDir(FtpDir.."/"..commandtab[3][2]) then
         local file = fs.open(FtpDir.."/"..commandtab[3][2], "rb")
         local fileData = {}
         local filebyte = file.read()
         repeat
          table.insert(fileData, filebyte)
          filebyte =file.read()
         until filebyte == nil
         file.close()
         fileData = ccaes.encrypt_bytestream(fileData, key, iv)
         local response = { hash.sha256("iv"..iv[16]), fileData }
         sendMessageS(response, sender)
         if loopoff == true then
          return true, sender, "getFile", commandtab[3][2]
         end
        else
         sendMessageS("fdne", sender)
         if loopoff == true then
          return false, sender, "getFile", "fdne"
         end
        end
       else
        sendMessageS("nea", sender)
        if loopoff == true then
         return false, sender, "getFile", "nea"
        end
       end

      elseif commandtab[3][1] == "pushFile" then
       if #commandtab[3] >= 3 then
        local decdat = ccaes.decrypt_bytestream(commandtab[3][3], key, iv)
        local file = fs.open(FtpDir.."/"..commandtab[3][2], "wb")
        for i = 1, #decdat do
         file.write(decdat[i])
        end
        file.close()
        sendMessageS("OK", sender)
        if loopoff == true then
         return true, sender, "pushFile", commandtab[3][2]
        end

       else
        sendMessageS("nea", sender)
        if loopoff == true then
         return false, sender, "pushFile", "nea"
        end
       end

      elseif commandtab[3][1] == "delFile" then
       if #commandtab[3] >= 2 then
        if fs.exists(FtpDir.."/"..commandtab[3][2]) then
         fs.delete(FtpDir.."/"..commandtab[3][2])
         sendMessageS("OK", sender)
         if loopoff == true then
          return true, sender, "delFile", commandtab[3][2]
         end
        else
         sendMessageS("fdne", sender)
         if loopoff == true then
          return false, sender, "delFile", "fdne"
         end
        end

       else
        sendMessageS("nea", sender)
        if loopoff == true then
         return false, sender, "delFile", "nea"
        end
       end

      else
       sendMessageS("nsc", sender)
       if loopoff == true then
        return false, sender, commandtab[3][1], "nsc"
       end
      end

     else
      sendMessageS("pww", sender)
      if loopoff == true then
       return false, sender, commandtab[3][1], "pww"
      end
     end

    else
     sendMessageS("nsu", sender)
     if loopoff == true then
      return false, sender, commandtab[3][1], "nsu"
     end
    end

   else
    sendMessageS("nea", sender)
    if loopoff == true then
     return false, sender, "nea"
    end
   end

  end

 else
  return "nMa"
 end

end

 -- creates a new user (should only be run on ftp server) returns true when finishing succesfull; returns nUsrN when no user is specified; returns nUsrP when no Password is specified; returns UsrE when user already exists
function createUser(UsrName, UsrPass, UsrDir)
 checkAPI()
 if UsrName == nil then return "nUsrN" end
 if UsrPass == nil then return "nUsrP" end
 local UsrDir = UsrDir or "/.ccftp/Users"
 if fs.exists(UsrDir.."/"..UsrName) or UsrName == "VerCheck" then return "UsrE" end
 local file = fs.open(UsrDir.."/"..UsrName, "w")
 file.writeLine(hash.sha256(UsrPass))
 file.close()
 return true
end

 -- renames an already existing User (should only be run on ftp server) returns true when successfull; returns noUsrN when oUsrName not specified; returns nnUsrN when nUsrName not specified; returns nUsrP when UsrPass not specified; returns nsUsr when User does not exists; returns nUsrE when target name exists;returns pww when password wrong
function renameUser(oUsrName, nUsrName, UsrPass, UsrDir)
 checkAPI()
 if oUsrName == nil then return "noUsrN" end
 if nUsrName == nil then return "nnUsrN" end
 if UsrPass == nil then return "nUsrP" end
 local UsrDir = UsrDir or "/.ccftp/Users"
 if not fs.exists(UsrDir.."/"..oUsrName) then return "nsUsr" end
 if fs.exists(UsrDir.."/"..nUsrName) or nUsrName == "VerCheck" then return "nUsrE" end
 local file = fs.open(UserDir.."/"..oUsrName, "r")
 local opass = file.readLine()
 file.close()
 if opass == hash.sha256(UsrPass) then
  fs.move(UsrDir.."/"..oUsrName, UsrDir.."/"..nUsrName)
  return true
 else
  return "pww"
 end
end

 -- changes the password from any existing User (should only be run on ftp server) returns true when successfull; returns nUsrN when UsrName not specified; returns noUsrP when oUsrPass not specified; returns nnUsrP when nUsrPass not specified; returns nsUsr when User does not exists; returns pww when password wrong
function changeUserPass(UsrName, oUsrPass, nUsrPass, UsrDir)
 checkAPI()
 if UsrName == nil then return "nUsrN" end
 if oUsrPass == nil then return "noUsrP" end
 if nUsrPass == nil then return "nnUsrP" end
 local UsrDir = UsrDir or "/.ccftp/Users"
 if not fs.exists(UsrDir.."/"..UsrName) then return "nsUsr" end
 local file = fs.open(UsrDir.."/"..UsrName, "r")
 local opass = file.readLine()
 file.close()
 if opass == hash.sha256(oUsrPass) then
  local file = fs.open(UsrDir.."/"..UsrName, "w")
  file.writeLine(hash.sha256(nUsrPass))
  file.close()
  return true
 else
  return "pww"
 end
end

 -- removes any given user (should only be run on ftp server) returns turn when successfull; returns nUsrN when UsrName not specified; returns nUsrP when UsrPass not specified; returns nsUsr when User does not exists; returns pww when password wrong
function removeUser(UsrName, UsrPass, UsrDir)
 checkAPI()
 if UsrName == nil then return "nUsrN" end
 if UsrPass == nil then return "nUsrP" end
 local UsrDir = UsrDir or "/.ccftp/Users"
 if not fs.exists(UsrDir.."/"..UsrName) then return "nsUsr" end
 local file = fs.open(UsrDir.."/"..UsrName)
 local opass = file.readLine()
 file.close()
 if opass == hash.sha256(UsrPass) then
  fs.delete(UsrDir.."/"..UsrName)
  return true
 else
  return "pww"
 end
end


 -- runs the Server Shell (should only be used in parralel with runServer) (currently broken; using code for example program)
local function runServerShell()
 local ServCol
 if term.isColor() then ServCol = {colors.yellow, colors.lightBlue} else ServCol = {colors.lightGray, colors.white} end
 local function clearShellScreen()
  term.setBackgroundColor(colors.black)
  term.clear()
  term.setCursorPos(1,1)
  term.setTextColor(ServCol[1])
  print("ccFTP Server Shell")
 end
 clearShellScreen()
 while(true) do
  local opull = os.pullEvent
  term.setTextColor(ServCol[2])
  write("-> ")
  term.setTextColor(colors.white)
  os.pullEvent = os.pullEventRaw
  local input = string.lower(read())
  os.pullEvent = opull
  if input == "reboot" then
   os.reboot()
  elseif input == "shutdown" then
   os.shutdown()
  elseif input == "close" then
   rednet.unhost("ccFTP", runningHost)
   break
  elseif input == "clear" then
   clearShellScreen()
  elseif input == "change hostname" then
   if runningHost ~= nil then
    os.pullEvent = os.pullEventRaw
    term.setTextColor(ServCol[2])
    print("Current Hostname: "..runningHost)
    write("New Hostname: ")
    term.setTextColor(colors.white)
    local input = read()
    os.pullEvent = opull
    if input ~= nil then
     rednet.unhost("ccFTP", runningHost)
     rednet.host("ccFTP", input)
     runningHost = input
    else
     printError("Please enter a Hostname!")
    end
   else
    print("There is no ccFTP Server running on this computer!")
   end
   os.pullEvent = opull
  elseif input == "create User" then
   os.pullEvent = os.pullEventRaw
   term.setTextColor(ServCol[2])
   print("User to create: ")
   term.setTextColor(colors.white)
   local user = read()
   if user ~= "" then
    term.setTextColor(ServCol[2])
    print("Password: ")
    term.setTextColor(colors.white)
    local pass = read("*")
    if pass ~= "" then
     local res = createUser(user, pass)
     if res == true then
      term.setTextColor(ServCol[1])
      print("User created!")
     elseif res == "UsrE" then
      printError("User already exists!")
     end
    else
     printError("Please specify a Password!")
    end
   else
    printError("Please specify a Username!")
   end
   os.pullEvent = opull
  elseif input == "change Username" then
   os.pullEvent = os.pullEventRaw
   term.setTextColor(ServCol[2])
   write("Current Username: ")
   term.setTextColor(colors.white)
   local oName = read()
   if oName ~= "" then
    term.setTextColor(ServCol[2])
    write("Current Password: ")
    term.setTextColor(colors.white)
    local pass = read("*")
    if pass ~= "" then
     term.setTextColor(ServCol[2])
     write("New Username: ")
     term.setTextColor(colors.white)
     local nName = read()
     if nName ~= "" then
      renameUser(oName, nName, pass)
      if res == true then
       term.setTextColor(ServCol[1])
       print("Renamed "..oName.." to "..nName)
      elseif res == "nsUsr" then
       printError("User doesn not exist!")
      elseif res == "nUsrE" then
       printError("New Username is already occupied!")
      elseif res == "pww" then
       printError("Password wrong!")
      end
     else
      printError("Please enter in the new Username!")
     end
    else
     printError("Please enter in the current Password!")
    end
   else
    printError("Please put in the current Username!")
   end
   os.pullEvent = opull
  elseif input == "change Password" then
   os.pullEvent = os.pullEventRaw
   term.setTextColor(ServCol[2])
   write("Username: ")
   term.setTextColor(colors.white)
   local Uname = read()
   if Uname ~= "" then
    term.setTextColor(ServCol[2])
    write("Current Password: ")
    term.setTextColor(colors.white)
    local opass = read("*")
    if opass ~= "" then
     term.setTextColor(ServCol[2])
     write("New Password: ")
     term.setTextColor(colors.white)
     local npass = read()
     if nName ~= "" then
      local res = changeUserPass(Uname, opass, npass)
      if res == true then
       term.setTextColor(ServCol[1])
       print("Changed Password from "..Uname)
      elseif res == "nsUsr" then
       printError("User does not exist!")
      elseif res == "pww" then
       printError("Password wrong!")
      end
     else
      printError("Please enter in the new Username!")
     end
    else
     printError("Please enter in the current Password!")
    end
   else
    printError("Please put in the current Username!")
   end
   os.pullEvent = opull
  elseif input == "delete User" then
   os.pullEvent = os.pullEventRaw
   term.setTextColor(ServCol[2])
   write("Username: ")
   term.setTextColor(colors.white)
   local Uname = read()
   if Uname ~= "" then
    term.setTextColor(ServCol[2])
    write("Password: ")
    term.setTextColor(colors.white)
    local pass = read("*")
    if pass ~= "" then
     local res = removeUser(Uname, pass)
     if res == true then
      term.setTextColor(ServCol[1])
      print("Deleted User "..Uname)
     elseif res == "nsUsr" then
      printError("User does not exists!")
     elseif res == "pww" then
      printError("Password wrong!")
     end
    else
     printError("Please enter in a password!")
    end
   else
    printError("Please specify the Username!")
   end
   os.pullEvent = opull
  end
 end
end


  ---- Client Functions ----

 -- gets the Directory Tree for the specified Subdirectory (optional)
function getDirCont(Hostname, UsrName, UsrPass, Subdir)
 if Hostname == nil then
  return "nHn"
 elseif UsrName == nil then
  return "nUsrN"
 elseif UsrPass == nil then
  return "nUsrP"
 end
 Subdir = Subdir or ""
 checkAPI()
 if checkModem() then
  local key, iv = unfoldkeyC(UsrPass)
  local hosterID = sendMessageC(Hostname, UsrName, hash.sha256("iv"..iv[15]), {"DirCont", Subdir})
  if hosterID then
   local response, senderID = waitForMessage("C")
   if senderID == hosterID then
    if response[2] ~= nil then
     return response[1], response[2]
    else
     return response
    end
   elseif senderID == nil then
    return "nsh"
   end
  elseif hosterID == nil then
   return "nsh"
  end
 else
  return "nMa"
 end
end

 -- gets a single File from FTP-Server (FileHost is the full path to the file in the Share ; FileClient sets the path where the file should be saved)
function getFile(Hostname, UsrName, UsrPass, FileHost, FileClient)
 if Hostname == nil then
  return "nHn"
 elseif UsrName == nil then
  return "nUsrN"
 elseif UsrPass == nil then
  return "nUsrP"
 elseif FileHost == nil then
  return "nFPH"
 elseif FileClient == nil then
  return "nFPC"
 end
 checkAPI()
 if checkModem() then
  local key, iv = unfoldkeyC(UsrPass)
  local hosterID = sendMessageC(Hostname, UsrName, hash.sha256("iv"..iv[15]), {"getFile", FileHost})
  if hosterID then
   local response, senderID = waitForMessage("C")
   if senderID == hosterID then
    if response[1] == hash.sha256("iv"..iv[16]) then
     local content = ccaes.decrypt_bytestream(response[2], key, iv)
     local file = fs.open(FileClient, "wb")
     for i = 1, #content do
      file.write(content[i])
     end
     file.close()
     return true
    else
     return response
    end
   elseif senderID == nil then
    return "nsh"
   end
  else
   return "nsh"
  end
 else
  return "nMa"
 end
end

 -- puts a single file onto the FTP-Server (FileClient is the path of the file which should be uploaded ; FileHost sets the full path, where the file should be saved)
function pushFile(Hostname, UsrName, UsrPass, FileClient, FileHost)
 if Hostname == nil then
  return "nHn"
 elseif UsrName == nil then
  return "nUsrN"
 elseif UsrPass == nil then
  return "nUsrP"
 elseif FileHost == nil then
  return "nFPH"
 elseif FileClient == nil then
  return "nFPC"
 elseif not fs.exists(FileClient) then
  return "FPCnE"
 end
 checkAPI()
 if checkModem() then
  local key, iv = unfoldkeyC(UsrPass)
  local file = fs.open(FileClient, "rb")
  local fileData = {}
  local fileByte = file.read()
  repeat
  table.insert(fileData, fileByte)
  fileByte = file.read()
  until fileByte == nil
  file.close()
  fileData = ccaes.encrypt_bytestream(fileData, key, iv)
  local hosterID = sendMessageC(Hostname, UsrName, hash.sha256("iv"..iv[15]), {"pushFile", FileHost, fileData})
  if hosterID then
   local response, senderID = waitForMessage("C")
   if senderID == hosterID then
    if response == "OK" then
     return true
    else
     return response
    end
   elseif senderID == nil then
    return "nsh"
   end
  else
   return "nsh"
  end
 else
  return "nMa"
 end
end

 -- removes a single File from the FTP-Server
function removeFile(Hostname, UsrName, UsrPass, FileHost)
 if Hostname == nil then
  return "nHn"
 elseif UsrName == nil then
  return "nUsrN"
 elseif UsrPass == nil then
  return "nUsrP"
 elseif FileHost == nil then
  return "nFPH"
 end
 checkAPI()
 if checkModem() then
  local key, iv = unfoldkeyC(UsrPass)
  local hosterID = sendMessageC(Hostname, UsrName, hash.sha256("iv"..iv[15]), {"delFile", FileHost})
  if hosterID then
   local response, senderID = waitForMessage("C")
   if senderID == hosterID then
    if response == "OK" then
     return true
    else
     return response
    end
   elseif senderID == nil then
    return "nsh"
   end
  elseif hosterID == nil then
   return "nsh"
  end
 else
  return "nMa"
 end
end