[Solved] crypt.au3 Fails to decrypt data and sets @error to 0

[Kyan]

Hi

I'm using crypt.au3 to store data in the programa .ini, but every time I tried to decode it, _crypt_decryptdata, sets @error = 0 and returns -1 (weird ah)

this is how I'm doing

Local $dhj, $dpass
_Crypt_Startup()
$dhj = _Crypt_DeriveKey(BinaryToString($password), $CALG_DES)
$dpass = _Crypt_DecryptData("0x" & $sCryptedData, $dhj, $CALG_USERKEY)
MsgBox(0,"",$dpass) ;returns -1
MsgBox(0,"",@error) ;returns 0
_Crypt_DestroyKey($dhj)
_Crypt_Shutdown()

I'm doing something wrong?

Edited October 11, 2012 by DiOgO

[water]

Does the example for _Crypt_DecryptData from the help file work for you?

How do you create $sCryptedData? Why do you prefix the crypted data with "0x"?

[water]

MsgBox(0, "", @error)

returns 0 because @error is set by the last called function. In your case by the preceding MsgBox. Change it to

MsgBox(0, "", $dpass & @CRLF & "@error = " & @error)

[Kyan]

MsgBox(0, "", @error)

returns 0 because @error is set by the last called function. In your case by the preceding MsgBox. Change it to

MsgBox(0, "", $dpass & @CRLF & "@error = " & @error)

well seen

I found that problem comes from _Crypt_EncryptData, after encrypt, the @error is set to 2, 2 - Failed to determine buffer, how can I solve this? (I'm using the same structure as DecryptData, derivkey > crypt)

edit:

Does the example for _Crypt_DecryptData from the help file work for you?

How do you create $sCryptedData? Why do you prefix the crypted data with "0x"?

I like it written as hex string in the .ini, thats why I trimmed left the crypted data, and for decrypt it I need to add "0x" before the $sCryptedData Edited October 10, 2012 by DiOgO

[guinness]

My question would be what AutoIt version? As well as did you check the help file example?

[Kyan]

My question would be what AutoIt version? As well as did you check the help file example?

SciTE 2.28, of course I check the help file, if you see my second comment, you'll find the exact sentence that is at help file, about @error 2

if I knew what is causing the error "Failed to determine buffer" would be easier to fix

EDIT: Now is working without change anything :s

Edited October 11, 2012 by DiOgO

[water]

Guinness wasn't asking for the SciTE version you use (that's the editor) but for the AutoIt version.

This can easily be retrieved by running

MsgBox(0, "", @AutoItVersion)

[guinness]

Thanks water. Also their version of SciTE is outdated too so they may want to upgrade to the latest version of SciTE4AutoIt3.

Could you also provide a working example as we have no idea what $password contains or $sCryptedData. The more you can provide the easier it will be.

This works for me:

#include <Crypt.au3>

Local $aStringsToEncrypt[6] = ["AutoIt", "SciTE", "Crypt", ".au3", 42, "42"]
Local $sOutput = ""

Local $hKey = _Crypt_DeriveKey("CryptPassword", $CALG_RC4) ; Declare a password string and algorithm to create a cryptographic key.

For $iWord In $aStringsToEncrypt
    $sOutput &= $iWord & @TAB & " = " & _Crypt_EncryptData($iWord, $hKey, $CALG_USERKEY) & @CRLF ; Encrypt the text with the cryptographic key.
Next

MsgBox(0, "Encrypted data", $sOutput)

_Crypt_DestroyKey($hKey) ; Destroy the cryptographic key.

[Kyan]

Guinness wasn't asking for the SciTE version you use (that's the editor) but for the AutoIt version.

This can easily be retrieved by running

MsgBox(0, "", @AutoItVersion)

sorry, 3.3.8.1 is the value returned

Thanks water. Also their version of SciTE is outdated too so they may want to upgrade to the latest version of SciTE4AutoIt3.

Could you also provide a working example as we have no idea what $password contains or $sCryptedData. The more you can provide the easier it will be.

This works for me:

#include <Crypt.au3>

Local $aStringsToEncrypt[6] = ["AutoIt", "SciTE", "Crypt", ".au3", 42, "42"]
Local $sOutput = ""

Local $hKey = _Crypt_DeriveKey("CryptPassword", $CALG_RC4) ; Declare a password string and algorithm to create a cryptographic key.

For $iWord In $aStringsToEncrypt
$sOutput &= $iWord & @TAB & " = " & _Crypt_EncryptData($iWord, $hKey, $CALG_USERKEY) & @CRLF ; Encrypt the text with the cryptographic key.
Next

MsgBox(0, "Encrypted data", $sOutput)

_Crypt_DestroyKey($hKey) ; Destroy the cryptographic key.

$password contains a simple alphanumeric passphrase, it is in binary, so I use binarytostring to retrieve the ansii text

$sCryptedData contains data, previously encrypt with the same algorithm ($CALG_DES) and with the same password

the error could be by caused by using a different derivekey?, since I wrote the data in a .ini, and in another execution it decrypts (tries unless) to a normal text string

PS: now I tried in my script (not in test script) I got the same error in decryption stage,

there's some incompatibility with these libraries?

#include <WinHttp.au3>

#include <GuiStatusBar.au3>
#include <GuiMenu.au3>
#include <array.au3>
#include <Date.au3>#include <GDIPlus.au3>

EDIT: I test the encrypt function and decode function, and it was able to encrypt this string 'Test!()'''

the problem could be with reading the encrypted data from .ini

EDIT2: Solved, I using a variable that was not set (only after some commands it would be set), thanks for the help guys

Edited October 11, 2012 by DiOgO

[guinness]

It wasn't the answer I was really looking for. Anyway with what information you have provided I can only conclude that this is how you do it.

#include <Crypt.au3>

Local $bPassword = StringToBinary('passwordexample')
Local $sPassword = BinaryToString($bPassword)
ConsoleWrite('Password: ' & $sPassword & @CRLF)

_Crypt_Startup()

Local $hKey = _Crypt_DeriveKey($sPassword, $CALG_DES)

Local $bEncryptedText = _Crypt_EncryptData('Random Text', $hKey, $CALG_USERKEY)
Local $sEncryptedText =  String($bEncryptedText)
ConsoleWrite($sEncryptedText & ' >> IsString: ' & IsString($sEncryptedText) & @CRLF)

Local $sDecryptText = BinaryToString(_Crypt_DecryptData($sEncryptedText, $hKey, $CALG_USERKEY))
ConsoleWrite($sDecryptText & ' >> IsString: ' & IsString($sDecryptText) & @CRLF)

_Crypt_DestroyKey($hKey)

_Crypt_Shutdown()

If not, then provide a small reproducer.

[Kyan]

It wasn't the answer I was really looking for. Anyway with what information you have provided I can only conclude that this is how you do it.

#include <Crypt.au3>

Local $bPassword = StringToBinary('passwordexample')
Local $sPassword = BinaryToString($bPassword)
ConsoleWrite('Password: ' & $sPassword & @CRLF)

_Crypt_Startup()

Local $hKey = _Crypt_DeriveKey($sPassword, $CALG_DES)

Local $bEncryptedText = _Crypt_EncryptData('Random Text', $hKey, $CALG_USERKEY)
Local $sEncryptedText = String($bEncryptedText)
ConsoleWrite($sEncryptedText & ' >> IsString: ' & IsString($sEncryptedText) & @CRLF)

Local $sDecryptText = BinaryToString(_Crypt_DecryptData($sEncryptedText, $hKey, $CALG_USERKEY))
ConsoleWrite($sDecryptText & ' >> IsString: ' & IsString($sDecryptText) & @CRLF)

_Crypt_DestroyKey($hKey)

_Crypt_Shutdown()

If not, then provide a small reproducer.

I already said what was the problem, I was trying to use a variable that is not set (a empty one, like: Global $myvar)

here's the code:

expandcollapse popup

#include 
Global $ini = @ScriptDir & "test.ini"
$bPassword = StringToBinary("mypassword")
$bEncdata = _enc("random data")
ConsoleWrite("Encrypted:"&$bEncdata&@CRLF)
If $bEncdata <> -1 Then IniWriteSection($ini,"Data","Encrypted="&$bEncdata)
If FileExists($ini) Then
$iEnc = IniRead($ini,"Data","Encrypted",'')
If $iEnc <> '' Then
$sDec = _dec($iEnc)
ConsoleWrite("Decrypted:"&$sDec&@CRLF)
EndIf
EndIf

Func _enc($idp)
Local $hj, $he
_Crypt_Startup()
$hj = _Crypt_DeriveKey(BinaryToString($bPassword), $CALG_DES)
$he = _Crypt_EncryptData($idp, $hj, $CALG_USERKEY)
_Crypt_DestroyKey($hj)
_Crypt_Shutdown()
Return StringTrimLeft($he,2)
EndFunc

Func _dec($inp)
Local $dhj, $dpass
_Crypt_Startup()
$dhj = _Crypt_DeriveKey(BinaryToString($bPassword), $CALG_DES)
$dpass = _Crypt_DecryptData("0x"&$inp, $dhj, $CALG_USERKEY)
_Crypt_DestroyKey($dhj)
_Crypt_Shutdown()
If $dpass = -1 Then
MsgBox(16,"ERROR","Bad encrypted data")
IniDelete($ini,"Data")
Return ''
Else
Return BinaryToString($dpass)
EndIf
EndFunc

[guinness]

At the time you made that second edit I didn't see it as I was already working on the example. You're welcome anyway.