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SiriusMonk
 
Posts: 2
Joined: Sat Jun 29, 2019 6:46 am

(WIN) AESDecoder - reload Ascii -file - in Memory problem

by SiriusMonk Sat Jun 29, 2019 7:25 am

Hello,

I hope someone can help me, the problem is that I do not get the contents of the text file completely in memory. And this text is not decoded by the AESDecoder command. Maybe I miss a small thing, but maybe not knowing how to do it :-( . Thank you in advance, if I come to the solution before I post it, of course :)

Code: Select all

Global *Buffer = AllocateMemory(256) ; Allocate a global memory buffer to avoid realloc
Global *MemoryID = AllocateMemory(256)
Global Text$

Enumeration
  #SelectFileGadget
EndEnumeration

; Easy procedure to convert a datasection to an allocated memory block
  ;
  Procedure DataSectionToMemory(Size)
    Protected *Buffer
    *Buffer = AllocateMemory(Size)
    For k = 0 To Size-1
      Read.b value
      PokeB(*Buffer, k, value)
    Next
    ProcedureReturn *Buffer
  EndProcedure
 
 
Procedure CallbackS(Status, Filename$, File, SizeRead)
    Select Status
      Case #PB_Status_Saved
        ; File correctly saved
      Case #PB_Status_Error
        ; File saving has failed
    EndSelect
EndProcedure
 


Procedure ReadCallback(Status, Filename$, File, Size)
  If Status = #PB_Status_Loaded
    ; Read all data into the memory buffer
     length = Lof(0) 
     Debug "LL "+ length
     ; get the length of opened file
     Text$= ReadString(0, #PB_Ascii, length)   ; read all data into the memory block
     Debug "read: " + Text$   

; maybe the problem part  Beginn

     If *MemoryID
       Debug "Decodieren"
       For k = 0 To 72
        TestView$ + Hex(PokeB(*MemoryID,1, k), #PB_Byte) + " "
       Next
       Debug "Test1:"+ Testview$
       
       PokeS(*MemoryID, 0, Text$, 128, #PB_Ascii)
       Dummy$=PeekS(*MemoryID, -1, #PB_Ascii)
       Debug "Test2 : "+ Dummy$ 

      Debug "Decodieren2"
      *DecodedText = AllocateMemory(256)
      AESDecoder(*MemoryID, 0, *DecodedText, 0, 128, *AESKey1, 256, *AESInitializationVector1)
      Debug "Decoded text: " + PeekS(*DecodedText, 0, 128, #PB_Ascii)
      Debug "Fertig"
      CloseFile(0) 
   EndIf
   
   ElseIf Status = #PB_Status_Error
    Debug "Error when loading the file: " + Filename$
  EndIf
 
  ; Decode it with the same InitializationVector and private key
 
EndProcedure

; maybe the problem part END     


Procedure OpenFileRequesterCallback()
  If NextSelectedFile()
    If ReadFile(0, SelectedFileID(), @ReadCallback(), #PB_LocalFile )
    EndIf
  EndIf
EndProcedure

Procedure ChooseFileEvent()
  OpenFileRequester("*.txt", @OpenFileRequesterCallback())
EndProcedure


 
; Mainprg  BEGIN
 
Text$ = "Single block msg1 Single block msg2 Single block msg3 Single block msg4"
Debug "Original text: " + Text$
 
; AES encoder can only work with memory buffer, so put our text in a memory buffer
*AsciiText = AllocateMemory(256)
PokeS(*AsciiText, 0, Text$, -1, #PB_Ascii)
; Get the InitializationVector value (needed for CBC encoding)

Restore AESInitializationVector1
*AESInitializationVector1 = DataSectionToMemory(16)
; Our private key
Restore AESKey1
*AESKey1 = DataSectionToMemory(32)
 
; The output buffer, needs to be input buffer size+1, aligned to the next 16-byte block
;
*Output = AllocateMemory(256)
AESEncoder(*AsciiText, 0, *Output, 0, 128, *AESKey1, 256, *AESInitializationVector1)
 
; Display the encoded message
;
For k = 0 To 72
    HexView$ + Hex(PeekB(*Output, k), #PB_Byte) + " "
Next
Debug "Text encoded (hex view): " + HexView$
 
 
If CreateFile(0, "Text.txt", @CallbackS())
   WriteStringN(0, HexView$)
   ExportFile(0, "text/plain")
   CloseFile(0)                     
 Debug "Datei geschrieben" 
EndIf

Debug "Datei wiedereinlesen"

If OpenWindow(0, 0, 0, 300, 80, "Decoder", #PB_Window_ScreenCentered)
  ButtonGadget(#SelectFileGadget, 10, 10, 280, 25, "Please choose text.txt ...")
  BindGadgetEvent(0, @ChooseFileEvent())
EndIf



; Main END

; *****************************
; Data
; *****************************


 
DataSection
    AESInitializationVector1:
      Data.b $3d, $af, $ba, $42, $9d, $9e, $b4, $30, $b4, $22, $da, $80, $2c, $9f, $ac, $41,$3d
 
 
    AESKey1:
      Data.b $06, $a9, $21, $40, $36, $b8, $a1, $5b, $51, $2e, $03, $d5, $34, $12, $00, $06,$06, $a9, $21, $40, $36, $b8, $a1, $5b, $51, $2e, $03, $d5, $34, $12, $00, $06
EndDataSection

 
 



juror
 
Posts: 9
Joined: Fri Aug 01, 2014 4:39 am

Re: (WIN) AESDecoder - reload Ascii -file - in Memory probl

by juror Sun Jun 30, 2019 7:25 pm

You appear to be writing a string output which is not a multiple of 16, thus you are unable to decode it.
SiriusMonk
 
Posts: 2
Joined: Sat Jun 29, 2019 6:46 am

Re: (WIN) AESDecoder - reload Ascii -file - in Memory probl

by SiriusMonk Wed Jul 03, 2019 7:50 am

juror wrote:You appear to be writing a string output which is not a multiple of 16, thus you are unable to decode it.


Thanks ! I will check this...
juror
 
Posts: 9
Joined: Fri Aug 01, 2014 4:39 am

Re: (WIN) AESDecoder - reload Ascii -file - in Memory probl

by juror Wed Jul 03, 2019 8:15 pm

Sorry, since you're using aes256 you should be aligned on a 32 byte boundary
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