File crypter\decrypter in XXTEA, Siccome siamo in vena di criptazione xD

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xdmisterx

Posted on 22/4/2010, 09:39

CITAZIONE

[...]L'XXTEA, tecnicamente parlando, è un cifrario a blocchi basato su una rete di Feistel non bilanciata, dove le due metà in cui è diviso il blocco di dati su cui opera la funzione non sono delle stesse dimensioni. L'XXTEA lavora, infatti, su blocchi di dimensione variabile la cui lunghezza è minimo 64 bit e multipla di 32 bit. Il numero dei cicli completi dipende dalla dimensione del blocco, ma devono comunque essere compresi fra un minimo di 6 ed un massimo di 32 (quando si utilizzano blocchi di piccole dimensioni).[...]

Wiki

Avendo trovato l'udf nel forum ufficiale, ho fatto questa semplice interfaccia per il suo utilizzo:

SPOILER (click to view)

CODICE

#include <GuiConstants.au3>
#include <WindowsConstants.au3>

Global $title = "File crypter XXTEA"

$gui = GUICreate($title,320,120,-1,-1,-1,0x00000010)

GUICtrlCreateGroup("Encrypt\decrypt file",10,10,300,100)
$file_path = GUICtrlCreateInput("",20,30,200,20)
GUICtrlSetTip($file_path,"The path of the file to encrypt or decrypt")
GUICtrlSetState($file_path,$GUI_DROPACCEPTED)
$open_dialog = GUICtrlCreateButton("Path...",225,30,80,20)
$del_file = GUICtrlCreateCheckbox("Delete the input file...",20,55)
$pwd = GUICtrlCreateInput("",20,80,200,20,0x0020)
GUICtrlSetTip($pwd,"The password")
$encdec = GUICtrlCreateButton("Enc\Dec",225,80,80,20)

GUISetState()

While 1
Switch GUIGetMsg()
Case $gui_event_close
Exit
Case $open_dialog
$path = FileOpenDialog($title,@ScriptDir,"All(*.*)")
If $path <> "" Then
GUICtrlSetData($file_path,$path)
EndIf
Case $encdec
$read_path = GUICtrlRead($file_path)
$pwd_r = GUICtrlRead($pwd)
If $read_path <> "" And $pwd_r <> "" Then
$open = FileOpen($read_path,0)
$read = FileRead($open)
FileClose($open)
$sp = StringSplit($read_path,".",2)
If $sp[UBound($sp)-1] = "fcx" Then
$data = _XXTEA_Decrypt($read,$pwd_r)
$sp_name = StringSplit($read_path,"\",2)
$file_decrypted = StringReplace($sp_name[UBound($sp_name)-1],".fcx","")
$file_decrypted_path = StringReplace($read_path,$sp_name[UBound($sp_name)-1],"")
$write = FileOpen($file_decrypted_path & $file_decrypted,2)
FileWrite($write,$data)
FileClose($write)
Else
$data = _XXTEA_Encrypt($read,$pwd_r)
$sp_name = StringSplit($read_path,"\",2)
$file_crypted = $sp_name[UBound($sp_name)-1] &".fcx"
$file_crypted_path = StringReplace($read_path,$sp_name[UBound($sp_name)-1],"")
$write = FileOpen($file_crypted_path & $file_crypted,2)
FileWrite($write,$data)
FileClose($write)
EndIf
If GUICtrlRead($del_file) = $gui_checked Then
FileDelete($read_path)
EndIf
EndIf
GUICtrlSetData($pwd,"")
EndSwitch
WEnd

Func _XXTEA_Encrypt($Data, $Key)
$Data = Binary($Data)
Local $DataLen = BinaryLen($Data)
If $DataLen = 0 Then
Return ""
ElseIf $DataLen < 8 Then
$DataLen = 8
EndIf

Local $Opcode = '0x83EC14B83400000099538B5C2420558B6C242056578B7C9DFCF7FB89C683C606C74424180000000085F68D76FF0F8EEA000000896C24288D4BFF8D549D00894C2410895424148974242081442418B979379E8B4C2418C1E90281E103000000894C241C31F6397424107E568B5424288BCF8B6CB204C1E9058D14AD0000000033CA8BD58BC7C1EA03C1E00433D003CA8B5424188BDE81E303000000335C241C8B4424308B1C9833D533DF03D333CA8B542428010CB28B0CB2463974241089CF7FAA8B5424288BCF8B2AC1E9058D14AD0000000033CA8BD58BC7C1EA03C1E00433D003CA8B5424188BDE81E303000000335C241C8B4424308B1C9833D533DF03D3FF4C242033CA8B542414014AFC8B4AFC8B54242089CF420F8F2DFFFFFF5F31C05E5D5B83C414C21000'
Local $CodeBuffer = DllStructCreate("byte[" & BinaryLen($Opcode) & "]")
DllStructSetData($CodeBuffer, 1, $Opcode)

Local $V = DllStructCreate("byte[" & Ceiling($DataLen / 4) * 4 & "]")
DllStructSetData($V, 1, $Data)

Local $K = DllStructCreate("byte[16]")
DllStructSetData($K, 1, $Key)

DllCall("user32.dll", "none", "CallWindowProc", "ptr", DllStructGetPtr($CodeBuffer), _
"ptr", DllStructGetPtr($V), _
"int", Ceiling($DataLen / 4), _
"ptr", DllStructGetPtr($K), _
"int", 0)

Local $Ret = DllStructGetData($V, 1)
$CodeBuffer = 0
$V = 0
$K = 0
Return $Ret
EndFunc

Func _XXTEA_Decrypt($Data, $Key)
$Data = Binary($Data)
Local $DataLen = BinaryLen($Data)
If $DataLen = 0 Then Return ""

Local $Opcode = '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
Local $CodeBuffer = DllStructCreate("byte[" & BinaryLen($Opcode) & "]")
DllStructSetData($CodeBuffer, 1, $Opcode)

Local $V = DllStructCreate("byte[" & Ceiling($DataLen / 4) * 4 & "]")
DllStructSetData($V, 1, $Data)

Local $K = DllStructCreate("byte[16]")
DllStructSetData($K, 1, $Key)

DllCall("user32.dll", "none", "CallWindowProc", "ptr", DllStructGetPtr($CodeBuffer), _
"ptr", DllStructGetPtr($V), _
"int", Ceiling($DataLen / 4), _
"ptr", DllStructGetPtr($K), _
"int", 0)

Local $Ret = DllStructGetData($V, 1)
$CodeBuffer = 0
$V = 0
$K = 0
Return $Ret
EndFunc

Cripta e decripta file.
Ho inserito l'opzione drag & drop per la scelta del file