[Gambas-user] Cipher

[Tobias Boege]

On Wed, 27 May 2020, Antonio Teixeira wrote:
> Hi everyone,
> 
> I am trying  to use ciper with "AES-128-XTS" method but I am always getting
> an error.
> 
>  hCipherText = Cipher[sAlgorithmus].Encrypt(sPlain, sKey, sInitVector)
> 
> In my case sPlain is a string with numbers, skey is an uuid
> ("cbfcc1173b5a4b83ae9a355079aae54c") and no mater the size of sInitVector I
> always get the error : InitVector length does not match method of FMain in
> line....
> 
> Any help please?
> 

The IV length for AES-128-XTS is 16 and I get no problems executing this:

  #!/usr/bin/env gbs3

  Use "gb.openssl"

  Public Sub Main()
    Dim sKey As String = "cbfcc1173b5a4b83ae9a355079aae54c"
    Dim sIV As String  = "0123456789abcdef"
    Dim hCrypt As CipherText

    Print "KeyLength:", Cipher["AES-128-XTS"].KeyLength == Len(sKey)
    Print "IvLength:",  Cipher["AES-128-XTS"].IvLength  == Len(sIV)
    hCrypt = Cipher["AES-128-XTS"].Encrypt(Format$(Now), sKey, sIV)
    Print "CipherText:", Base64$(hCrypt.Cipher)
    Print "Decrypted:", Cipher["AES-128-XTS"].Decrypt(hCrypt)
  End

  ==========================================================================

  KeyLength:      True
  IvLength:       True
  CipherText:     6NuzSxByac+p+DD2qLuRmqpTTw==
  Decrypted:      05/27/2020 21:59:27

Regards,
Tobias

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk