; Demo: Streaming AES file encode/decode 
	; netmaestro August 2010 
	; Purebasic 4.51 
	 
	Declare Encode(void) 
	Declare Decode(void) 
	 
	OpenWindow(0,0,0,200,120,"Cryptor!",#PB_Window_SystemMenu|#PB_Window_ScreenCentered) 
	ButtonGadget(0, 50,20,100,20,"Encrypt a file") 
	ButtonGadget(1, 50,50,100,20,"Decrypt a file") 
	CreateStatusBar(0, WindowID(0)) 
	AddStatusBarField(200) 
	StatusBarProgress(0,0,0,#PB_ProgressBar_Smooth,0,100) 
	 
	Repeat 
	EventID = WaitWindowEvent() 
	Select EventID 
	Case #PB_Event_Gadget 
	Select EventGadget() 
	Case 0 
	CreateThread(@Encode(), 0) 
	 
	Case 1 
	CreateThread(@Decode(), 0) 
	EndSelect 
	EndSelect 
	Until EventID = #PB_Event_CloseWindow 
	 
	End 
	 
	 
	Procedure Encode(void) 
	 
	chunksize = 4096 
	rawfilename$ = OpenFileRequester("Please choose a file to encrypt:","","",0) 
	encfilename$ = rawfilename$+".enc" 
	 
	If OpenFile(0, rawfilename$) 
	If CreateFile(1, encfilename$) 
	DisableGadget(0,1) 
	DisableGadget(1,1) 
	 
	length.q = Lof(0) 
	numparts = length/chunksize 
	lastchunksize = length%chunksize 
	If lastchunksize 
	numparts+1 
	lastchunk = numparts 
	Else 
	lastchunk = 0 
	EndIf 
	 
	*raw     = AllocateMemory(chunksize)  
	*secure  = AllocateMemory(chunksize)  
	 
	StartAESCipher(0, ?key, 256, ?iVector, #PB_Cipher_CBC|#PB_Cipher_Encode) 
	 
	For i=1 To numparts 
	If i=lastchunk 
	FillMemory(*raw, chunksize, 0, #PB_Byte) 
	ReadData(0, *raw, lastchunksize) 
	Else 
	ReadData(0, *raw, chunksize) 
	EndIf 
	AddCipherBuffer(0, *raw, *secure, chunksize) 
	WriteData(1, *secure, chunksize) 
	prog.d = i/numparts*100 
	StatusBarProgress(0,0, Int(prog)) 
	Delay(1) 
	Next 
	If lastchunksize 
	WriteLong(1, lastchunksize) 
	Else 
	WriteLong(1, chunksize) 
	EndIf 
	 
	FinishCipher(0)  
	CloseFile(0) 
	CloseFile(1) 
	 
	FreeMemory(*raw) 
	FreeMemory(*secure) 
	 
	MessageRequester("Finished", "Encrypted file "+encfilename$+" saved",#MB_ICONINFORMATION) 
	StatusBarProgress(0,0,0) 
	 
	DisableGadget(0,0) 
	DisableGadget(1,0) 
	 
	EndIf 
	EndIf 
	EndProcedure 
	 
	Procedure Decode(void) 
	 
	chunksize = 4096 
	 
	encfilename$ = OpenFileRequester("Please choose a file to decrypt:","","",0) 
	rawfilename$ = SaveFileRequester("Please choose a new name for the decrypted file","","",0) 
	 
	If OpenFile(0, encfilename$) 
	FileSeek(0, Lof(0)-4) 
	lastchunksize = ReadLong(0) 
	FileSeek(0, 0) 
	If CreateFile(1, rawfilename$) 
	DisableGadget(0,1) 
	DisableGadget(1,1) 
	 
	length.q = Lof(0) 
	numparts = length/chunksize 
	 
	*raw     = AllocateMemory(chunksize)  
	*secure  = AllocateMemory(chunksize)  
	 
	StartAESCipher(0, ?key, 256, ?iVector, #PB_Cipher_CBC|#PB_Cipher_Decode) 
	 
	For i=1 To numparts 
	ReadData(0, *secure, chunksize) 
	AddCipherBuffer(0, *secure, *raw, chunksize) 
	If i=numparts 
	WriteData(1, *raw, lastchunksize) 
	Else 
	WriteData(1, *raw, chunksize) 
	EndIf 
	prog.d = i/numparts*100 
	StatusBarProgress(0,0, Int(prog)) 
	Delay(1) 
	Next 
	 
	FinishCipher(0)  
	CloseFile(0) 
	CloseFile(1) 
	 
	FreeMemory(*raw) 
	FreeMemory(*secure) 
	 
	MessageRequester("Finished", "Decrypted file "+rawfilename$+" saved",#MB_ICONINFORMATION) 
	StatusBarProgress(0,0,0) 
	 
	DisableGadget(0,0) 
	DisableGadget(1,0) 
	EndIf 
	EndIf 
	EndProcedure 
	 
	 
	DataSection 
	key: 
	Data.b $8C,$15,$51,$2C,$0C,$8A,$0A,$D8,$07,$E4,$21,$A2,$8E,$83,$A3,$88,$8A,$CA,$FB,$E1 
	Data.b $7B,$A3,$6B,$D6,$BC,$F7,$E6,$CD,$FE,$B5,$D7,$B3 
	iVector: 
	Data.b $08,$0C,$96,$48,$33,$51,$35,$80,$0C,$A9,$42,$1E,$11,$E0,$83,$C7,$C4,$C6,$E1,$E4 
	Data.b $2E,$40,$81,$0A,$24,$70,$00,$10,$08,$B3,$64,$21 
	EndDataSection