Encrytion Help

[niftyapple]

Hey everyone!

I was just trying to perfect my encryption skills and I think I have confused myself more than done any good.

Been trying to follow the documentation given by the SCITE editor(you will see that I copied a lot of this from that directly to avoid making mistakes) but I cant get the decrypt process to work.

My test code I hope to use as proof of concept to store an encrypted password in a file for retrieval and decryption then use later on. Here is what I have so far.

I put some _ArrayDisplay's in to see the encryption process at work through its various stages, but as you can tell by running this, the last array display after attempting to decrypt, it doesnt turn out as the original array.
 

Help?!

#include <Crypt.au3>
#include <File.au3>
#include <Array.au3>
 
Local $aStringsToEncrypt[6] = ["AutoIt", "SciTE", "Crypt", ".au3", 42, "42"]
Local $test[6]
Local $hKey = _Crypt_DeriveKey("CryptPassword", $CALG_RC4) ; Declare a password string and algorithm to create a cryptographic key.

For $i = 0 to 5
   $test[$i] = _Crypt_EncryptData($aStringsToEncrypt[$i], $hKey, $CALG_USERKEY)
Next

_ArrayDisplay($test)

_FileWriteFromArray(@DesktopDir & "\encrypt.txt", $test)
;~ ----------------------
Local $test2
_FileReadToArray(@DesktopDir & "\enc.txt", $test2)

_ArrayDisplay($test2)

;~ UnEncrypt test
Local $unenc[6]
For $i = 1 to 6
   $unenc[$i-1] = _Crypt_DecryptData($test2[$i], $hKey, $CALG_USERKEY)
Next

_ArrayDisplay($unenc)

[BrewManNH]

I'm not sure, but it appears you're writing to one file and reading from another.

_FileWriteFromArray(@DesktopDir & "\encrypt.txt", $test)
;~ ----------------------
Local $test2
_FileReadToArray(@DesktopDir & "\enc.txt", $test2)

The write is to encrypt.txt, the read is from enc.txt. Is that intentional?

[niftyapple]

Woops, I did not mean to do that. I have updated it and here is the output of the 3rd display, still not the intended output.

 

[0]|0x4175746F4974
[1]|0x5363695445
[2]|0x4372797074
[3]|0x2E617533
[4]|0x2A000000
[5]|0x3432
 

Edited September 11, 2014 by niftyapple

[BrewManNH]

I missed this in your code the first time through, you need to change the following line.

; From this
$unenc[$i-1] = _Crypt_DecryptData($test2[$i], $hKey, $CALG_USERKEY)
; To this
$unenc[$i-1] = BinaryToString(_Crypt_DecryptData($test2[$i], $hKey, $CALG_USERKEY))

As the help file explains, the decrypted data is returned as a binary string, so you need to convert that string to the correct format with BinaryToString to be able to read it.

[niftyapple]

Ok, now I feel like I am just going to walk away from the keyboard for a while.

I was playing with this last night, also getting frustrated but was converting with binarytostring. Not sure why, when I simplified the code, that I didnt put that in the "tech demo".

Thanks again, thats a winner.

[BrewManNH]

Glad I could help.

[kudrow]

I am not having the exact issue but what I am facing is that once I send the encrypted data over TCP it is not received in its original form. I can send the string over just fine but when it gets encrypted and sent it gets all jacked up. It looks like wingdings. Any thoughts?

Thanks!

[kudrow]

Take a look at my 2 screen shots and you will see what I am talking about. Keep in mind I am not trying to decrypt anything "YET" at the receiving end. I just want to see consistent data from point A to point B. 

The encrypted data being sent.

The same data received from TCP

Anyone have any thoughts?

[kudrow]

I figured it out. I tried converting the encrypted data to "StringToBinary" before sending it and it works now. Of course I have to do BinaryToString before decrypting and then BinaryToString after decrypting. I hope this helps someone later down the road.

Thanks!

[jchd]

And don't forget to send UTF8 data so you receive UTF8 data! See options for said functions.