AutoHotkey Community

SetBatchLines -1
#NoTrayIcon
#SingleInstance Off
Loop %0%
 File := %A_Index%

RegRead Setting, HKEY_CURRENT_USER, Software\Simcrypt
if (Setting = "Unique")
 {
 if (A_OSVersion = "WIN_VISTA")
  RegRead Key, HKEY_LOCAL_MACHINE, SOFTWARE\Microsoft\Windows NT\CurrentVersion, ProductID
 else
  RegRead Key, HKEY_LOCAL_MACHINE, SOFTWARE\Microsoft\Windows\CurrentVersion, ProductID
 goto Encrypt
 }
else if (Setting = "User")
 RegRead Key, HKEY_CURRENT_USER, Software\Simcrypt, User
else
 {
  Gui Add, Edit, vKey w125
  Gui Add, Button, x43 default, Encrypt
  Gui Show,, Key
  return
 }

ButtonEncrypt:
Gui Submit


Encrypt:
BinRead(File, Text, 0, 0)
FileGetSize Size, %File%, M
if Size > 0
 FileCopy %File%, %File%.bak
FileDelete %File%
FileAppend % VxEncrypt(Key, Text), %File%
FileDelete %File%.bak
GuiClose:
ExitApp

VxEncrypt(key, message, CryptEvent = "")
{
   LowerBound = 34
   UpperBound = 126
   StringReplace, Message, Message, `r`n, `n, all
   StringLeft, CryptEvent, CryptEvent, 1
   If !CryptEvent
      CryptEvent = e
   Loop, parse, key
      key .= "`n" Asc(A_LoopField)
   key := SubStr(key, InStr(Key, "`n",0,1)+1)
   NewMessage =
   Loop, Parse, Message
   {
      code := Asc(A_LoopField)
      If ( code >= LowerBound ) && ( code <= UpperBound )
      {
         mco := code
         prevc := A_Index
         newkey := ""
         Loop, Parse, key, `n
            code := Clamp(( code - (A_LoopField * ( Mod(A_LoopField, 2)
            * 2 - 1 )) * ((CryptEvent = "e") * 2 - 1) ), LowerBound, UpperBound )
         If CryptEvent = e
            mco := code
         Loop, Parse, key, `n
            newkey .= "`n" (prevc := Clamp((A_LoopField + mco * (Mod((mco
            +Prevc), 2) * 2 - 1) + Prevc), 1, 255))
         key := SubStr( newkey, 2 )
      }
      NewMessage .= Chr(code)
   }
return % NewMessage
}

clamp( number, low, high )
{
   span := (high - low + (high > low)*2 - 1)
   return number + span * Round(((low-number)/2 + (high-number)/2)/span)
}

BinRead(file, ByRef data, n=0, offset=0)
{
   h := DllCall("CreateFile","Str",file,"Uint",0x80000000,"Uint",3,"UInt",0,"UInt",3,"Uint",0,"UInt",0)
   IfEqual h,-1, SetEnv, ErrorLevel, -1
   IfNotEqual ErrorLevel,0,Return,0

   m = 0
   IfLess offset,0, SetEnv,m,2
   r := DllCall("SetFilePointerEx","Uint",h,"Int64",offset,"UInt *",p,"Int",m)
   IfEqual r,0, SetEnv, ErrorLevel, -3
   IfNotEqual ErrorLevel,0, {
      t = %ErrorLevel%
      DllCall("CloseHandle", "Uint", h)
      ErrorLevel = %t%
      Return 0
   }

   TotalRead = 0
   data =
   IfEqual n,0, SetEnv n,0xffffffff

   format = %A_FormatInteger%
   SetFormat Integer, Hex

   Loop %n%
   {
      result := DllCall("ReadFile","UInt",h,"UChar *",c,"UInt",1,"UInt *",Read,"UInt",0)
      if (!result or Read < 1 or ErrorLevel)
         break
      TotalRead += Read
      c += 0
      StringTrimLeft c, c, 2
      c = 0%c%
      StringRight c, c, 2
      data = %data%%c%
   }

   IfNotEqual ErrorLevel,0, SetEnv,t,%ErrorLevel%

   h := DllCall("CloseHandle", "Uint", h)
   IfEqual h,-1, SetEnv, ErrorLevel, -2
   IfNotEqual t,,SetEnv, ErrorLevel, %t%

   SetFormat Integer, %format%
   Totalread += 0
   Return TotalRead
}

SetBatchLines -1
#NoTrayIcon
#SingleInstance Off
Loop %0%
 File := %A_Index%
FileRead Text, %File%

RegRead Setting, HKEY_CURRENT_USER, Software\Simcrypt
if (Setting = "Unique")
 {
 if (A_OSVersion = "WIN_VISTA")
  RegRead Key, HKEY_LOCAL_MACHINE, SOFTWARE\Microsoft\Windows NT\CurrentVersion, ProductID
 else
  RegRead Key, HKEY_LOCAL_MACHINE, SOFTWARE\Microsoft\Windows\CurrentVersion, ProductID
 goto Decrypt
 }
else if (Setting = "User")
 RegRead Key, HKEY_CURRENT_USER, Software\Simcrypt, User
else
 {
  Gui Add, Edit, vKey w125
  Gui Add, Button, x43 default, Decrypt
  Gui Show,, Key
  return
 }

ButtonDecrypt:
Gui Submit

Decrypt:
BinText := VxEncrypt(Key, Text,1)
FileDelete %File%
BinWrite(File, BinText, 0, 0)
GuiClose:
ExitApp

VxEncrypt(key, message, CryptEvent = "")
{
   LowerBound = 34
   UpperBound = 126
   StringReplace, Message, Message, `r`n, `n, all
   StringLeft, CryptEvent, CryptEvent, 1
   If !CryptEvent
      CryptEvent = e
   Loop, parse, key
      key .= "`n" Asc(A_LoopField)
   key := SubStr(key, InStr(Key, "`n",0,1)+1)
   NewMessage =
   Loop, Parse, Message
   {
      code := Asc(A_LoopField)
      If ( code >= LowerBound ) && ( code <= UpperBound )
      {
         mco := code
         prevc := A_Index
         newkey := ""
         Loop, Parse, key, `n
            code := Clamp(( code - (A_LoopField * ( Mod(A_LoopField, 2)
            * 2 - 1 )) * ((CryptEvent = "e") * 2 - 1) ), LowerBound, UpperBound )
         If CryptEvent = e
            mco := code
         Loop, Parse, key, `n
            newkey .= "`n" (prevc := Clamp((A_LoopField + mco * (Mod((mco
            +Prevc), 2) * 2 - 1) + Prevc), 1, 255))
         key := SubStr( newkey, 2 )
      }
      NewMessage .= Chr(code)
   }
return % NewMessage
}


clamp( number, low, high )
{
   span := (high - low + (high > low)*2 - 1)
   return number + span * Round(((low-number)/2 + (high-number)/2)/span)
}


BinWrite(file, data, n=0, offset=0)
{

   h := DllCall("CreateFile","str",file,"Uint",0x40000000,"Uint",0,"UInt",0,"UInt",4,"Uint",0,"UInt",0)
   IfEqual h,-1, SetEnv, ErrorLevel, -1
   IfNotEqual ErrorLevel,0,Return,0

   m = 0
   IfLess offset,0, SetEnv,m,2
   r := DllCall("SetFilePointerEx","Uint",h,"Int64",offset,"UInt *",p,"Int",m)
   IfEqual r,0, SetEnv, ErrorLevel, -3
   IfNotEqual ErrorLevel,0, {
      t = %ErrorLevel%
      DllCall("CloseHandle", "Uint", h)
      ErrorLevel = %t%
      Return 0
   }

   TotalWritten = 0
   m := Ceil(StrLen(data)/2)
   If (n <= 0 or n > m)
       n := m
   Loop %n%
   {
      StringLeft c, data, 2
      StringTrimLeft data, data, 2
      c = 0x%c%
      result := DllCall("WriteFile","UInt",h,"UChar *",c,"UInt",1,"UInt *",Written,"UInt",0)
      TotalWritten += Written
      if (!result or Written < 1 or ErrorLevel)
         break
   }

   IfNotEqual ErrorLevel,0, SetEnv,t,%ErrorLevel%

   h := DllCall("CloseHandle", "Uint", h)
   IfEqual h,-1, SetEnv, ErrorLevel, -2
   IfNotEqual t,,SetEnv, ErrorLevel, %t%

   Return TotalWritten
}

#NoTrayIcon
SetBatchLines -1
Gui -Caption
Gui Color, 0x80B2D3
Gui Add, Edit, r10 ReadOnly,
(
SYMCRYPT v. 1.4
------------------------------
V 1.4
  Context Menu support for all file types
  Backup files larger than 1MB during encryption
V 1.3
  New encryption method
  Read/Write binary
v 1.2
 Encrypt .txt files
  - Drag-n-Drop to the EXE or
  - Right click the .txt file and choose Encrypt.
  - Computer Specific Key
  - Set default key

About Simcrypt
-----------------
Simcrypt is a simple encryption program.

Currently Simcrypt can only encrypt simple text files.

This program should not be used for any serious
purposes, the encryption level is very weak and
errors may occur.

Any feedback or questions can be sent to
  abhishek.regmi@gmail.com

Use at your own risk.
)
Gui Font, s15
Gui Add, Button, w100 x30 y150,Install
Gui Add, Button, w100 x145 y150, Exit
Gui Show, w280 h200
return

ButtonInstall:
IfExist %A_ProgramFiles%\Simpcrypt\
 FileRemoveDir, %A_ProgramFiles%\Simpcrypt\, 1
FileCreateDir %A_ProgramFiles%\Simpcrypt\
FileInstall Encrypt.exe, %A_ProgramFiles%\Simpcrypt\Encrypt.exe
FileInstall Decrypt.exe, %A_ProgramFiles%\Simpcrypt\Decrypt.exe
FileInstall Options.exe, %A_ProgramFiles%\Simpcrypt\Options.exe
FileInstall Uninstall.exe, %A_ProgramFiles%\Simpcrypt\Uninstall.exe
FileCreateDir %A_StartMenuCommon%\Simpcrypt\
FileCreateShortcut %A_ProgramFiles%\Simpcrypt\Options.exe, %A_StartMenuCommon%\Simpcrypt\Options.lnk
FileCreateShortcut %A_ProgramFiles%\Simpcrypt\Uninstall.exe, %A_StartMenuCommon%\Simpcrypt\Uninstall.lnk


RegWrite REG_SZ, HKEY_CLASSES_ROOT, *\shell\Encrypt\Command, , "%A_ProgramFiles%\Simpcrypt\Encrypt.exe" "`%0"
RegWrite REG_SZ, HKEY_CLASSES_ROOT, *\shell\Decrypt\Command, , "%A_ProgramFiles%\Simpcrypt\Decrypt.exe" "`%0"
Msgbox Symcrypt has successfully been installed!
ButtonExit:
GuiClose:
ExitApp

FileRemoveDir %A_ProgramFiles%\Simpcrypt\, 1
FileRemoveDir %A_StartMenuCommon%\Simpcrypt, 1
RegDelete HKEY_CLASSES_ROOT, *\shell\Encrypt\
RegDelete HKEY_CLASSES_ROOT, *\shell\Decrypt\
RegDelete HKEY_CURRENT_USER, Software\Simcrypt
Msgbox Symcrypt has successfully been uninstalled!

#SingleInstance Force
SetBatchLines -1
RegRead Setting, HKEY_CURRENT_USER, Software\Simcrypt
Gui Color, 0x80B2D3
Gui Add, Text, , OPTIONS
Gui Add, CheckBox, x15 y30 vUnique, Auto-Gen Key
Gui Add, CheckBox, x15 y50 vDefault, User Defined Key
Gui Add, Edit, x25 y72 vUserKey, Pur|_01n3d
Gui Add, CheckBox, x15 y95 vSelect, Manual Key
Gui Add, Button, default, Submit

if (Setting = Unique)
 GuiControl, , Unique, 1
else if (Setting = User)
 {
  RegRead UserKey, HKEY_CURRENT_USER, Software\Simcrypt, User
  GuiControl, , Default, 1
  GuiControl, , UserKey, %UserKey%
 }
else
 GuiControl, , Select, 1
Gui Show, w250 h200, Encrypt Options
return



ButtonSubmit:
Gui Submit
if (Unique = 1)
 RegWrite REG_SZ, HKEY_CURRENT_USER, Software\Simcrypt, , Unique
else if (Default = 1)
 {
  RegWrite REG_SZ, HKEY_CURRENT_USER, Software\Simcrypt, , User
  RegWrite REG_SZ, HKEY_CURRENT_USER, Software\Simcrypt, User, %UserKey%
 }
else if (Select = 1)
 RegWrite REG_SZ, HKEY_CURRENT_USER, Software\Simcrypt, , Manual
Msgbox Changes have been made!
GuiClose:
ExitApp

...
Create a backup copy of the file before encryption
...