#!/usr/bin/env murgaLua

-- GUI for steghide <steghide.sourceforge.net>
-- function is limited to embedding data into jpg
-- 2010 mikshaw
-- version 0.1

function apply_img(img)
image=img -- global image filename
local imgdata=fltk:Fl_JPEG_Image(img)
local w=imgdata:w()
local h=imgdata:h()
if w>0 and h>0 then imgbox:image(imgdata) end
  local outname=string.gsub(image,"(.*)%..*","%1_stego.jpg")
  outpoot:value(outname)
-- display image info/capacity in menu bar
local my_cmd=io.popen("steghide info "..image.." -p nothing")
local my_result=my_cmd:read("*a")
my_cmd:close()
local cap_str=string.gsub(my_result,".*capacity:%s*([%d%.]*%s*%a+).*","%1")
local cap_num=string.gsub(cap_str,"([%d%.]*).*","%1")
local cap_fmt=string.gsub(cap_str,"[%d%.%s]*(%a+)","%1")
if cap_fmt=="Byte" then cap_num=math.floor(cap_num); mult=1
elseif cap_fmt=="KB" then mult=1024 end
local chars=math.floor(cap_num*mult)
imgbar:menu(0):label(fltk.fl_filename_name(img)..
" | "..w.."x"..h.." | embed capacity: "..cap_str)
textfield:label("Your message ("..chars.." character limit for this image):")
textfield:redraw_label()
imgbox:size(w,h)
imgscr:position(0,0)
imgscr:redraw()
imgbar:redraw()
end

function choose_img()
local img=fltk.fl_file_chooser("Choose a JPEG","*.jp{e,}g",nil,0)
if img then apply_img(img) end
end

function choose_target()
local target=fltk.fl_file_chooser("Save As...","*.jp{e,}g",nil,0)
if target then outpoot:value(target) end
end

function write_file()
if not image then
  tabs:value(t1)
  fltk.fl_alert("You must choose an image file.")
  return
end
if outpoot:value()=="" then
  fltk.fl_alert("You must supply an output filename.")
  return
end
if embpass:value()=="" then
  fltk.fl_alert("You must set a password.")
  return
end
local tmp=os.tmpname()..".txt"
local out=io.open(tmp,"w")
if out then
  out:write(textfield:value())
  out:close()
else
  fltk.fl_alert("Can't read "..tmp.." for some reason")
end
if overw:value()==1 then ow=" -f " else ow="" end
os.execute("steghide embed -ef "..tmp.." -cf "..image.." -sf "..outpoot:value()..
" -p "..embpass:value()..ow.." -e "..enc_menu:text(enc_menu:value()).." "..mod_menu:text(mod_menu:value()))
os.remove(tmp)
end

function extract(cmd)
if not image then
  tabs:value(t1)
  fltk.fl_alert("You must choose an image file.")
  return
end
if extpass:value()=="" then
  fltk.fl_alert("You must supply a password.")
  return
end
local my_cmd=io.popen("steghide "..cmd..image.." -p "..extpass:value())
local my_result=my_cmd:read("*a")
my_cmd:close()
extbuff:append(my_result.."\n")
end


bh=30; ww=500; wh=bh*20
w=fltk:Fl_Double_Window(ww,wh,"Steghide")
tabs=fltk:Fl_Tabs(0,0,ww,wh)

-- IMAGE TAB --
t1=fltk:Fl_Group(0,bh,ww,wh-bh,"image file")
t1:selection_color(46)
imgbar=fltk:Fl_Menu_Bar(0,bh,ww,bh)
imgbar:add("click here to choose an image")
imgbar:menu(0):callback(choose_img)
imgscr=fltk:Fl_Scroll(0,bh*2,ww,wh-bh*2)
imgbox=fltk:Fl_Box(0,bh*2,ww,wh-bh*2)
fltk:Fl_End() --imgscr
imgbox:align(85)
fltk:Fl_End() --t1

-- EMBED TAB --
t2=fltk:Fl_Group(0,bh,ww,wh-bh,"embed")
t2:selection_color(46)
embpass=fltk:Fl_Secret_Input(10,bh*2,ww-20,bh,"password:")
textfield=fltk:Fl_Multiline_Input(10,bh*4,ww-20,bh*10)
textfield:align(5)
textfield:label("Type your secret message here")
enc_menu=fltk:Fl_Choice(10,bh*15+10,ww/2-10,bh,"encryption:")
mod_menu=fltk:Fl_Choice(ww/2,bh*15+10,ww/2-10,bh,"mode:")
enc_menu:align(5); mod_menu:align(5)
enc_menu:add("none")
-- get encinfo
enc_info=io.popen("steghide encinfo")
enc_data=enc_info:read("*a")
enc_info:close()
-- first 2 lines are useless
enc_data=string.gsub(enc_data,".*%.%.%.%s*(.*)%s*\n","%1")
count=0
-- create table for encryption modes
enc_tab={}
for line in string.gmatch(enc_data,".-\n") do
  count=count+1
  e=string.gsub(line,"(.-):(.*)","%1")
  m=string.gsub(line,".-:(.*)","%1")
  enc_tab[count]={}
  for i in string.gmatch(m,"%w+") do
    table.insert(enc_tab[count],i)
  end
  if e == "rijndael-128" then enc_def=count end
  enc_menu:add(e)
end
-- select the default encoding
enc_menu:value(enc_def)
outpoot=fltk:Fl_File_Input(10,bh*17,ww-20-bh,bh,"save as:")
ch_target=fltk:Fl_Button(ww-bh-10,bh*17,bh,bh,"@>")
ch_target:callback(choose_target)
outpoot:align(5); embpass:align(5)
save=fltk:Fl_Button(10,bh*18,bh*3,bh,"save")
save:callback(write_file)
overw=fltk:Fl_Round_Button(bh*4,bh*18,bh*4,bh,"overwrite an existing file?")
enc_menu:callback(function()
mod_menu:clear()
mod_menu:add(" ")
if enc_menu:value()==0 then mod_menu:value(0)
else
for k,v in pairs(enc_tab[enc_menu:value()]) do
  mod_menu:add(v)
end
mod_menu:value(1)
end
end)
enc_menu:do_callback()
fltk:Fl_End() --t2

-- EXTRACT TAB --
t3=fltk:Fl_Group(0,bh,ww,wh-bh,"extract")
t3:selection_color(46)
exttext=fltk:Fl_Text_Display(10,bh*4,ww-20,bh*15)
extbuff=fltk:Fl_Text_Buffer()
exttext:buffer(extbuff)
extpass=fltk:Fl_Secret_Input(10,bh*2,ww-20,bh,"password:")
extpass:align(5)
infobutt=fltk:Fl_Button(10,bh*3,bh*3,bh,"get info")
infobutt:callback(function() extract("info ") end)
astext=fltk:Fl_Button(10+bh*3,bh*3,bh*3,bh,"extract text")
astext:callback(function() extract("extract  -f -xf - -sf ") end)
-- The asfile feature doesn't work well with lua
--asfile=fltk:Fl_Button(10+bh*6,bh*3,bh*3,bh,"extract file")
--asfile:callback(function() extract("extract -sf ") end)
fltk:Fl_End() --t3
fltk:Fl_End() --tabs

if arg[1] then apply_img(arg[1]) end

w:resizable(tabs)
tabs:resizable(t1)
tabs:resizable(t2)
tabs:resizable(t3)
t1:resizable(imgscr)
t2:resizable(textfield)
t3:resizable(exttext)
w:show()
Fl:run()