Encrypt Binary file

[usera]

Greeting,

I have a task to encrypt a Binary file., What I am thinking the easiest way is as below.

1. open that binary file (size unknown)

2. read all content in the memory (buffer)

3. read each byte then Add 01(Hex).

4. write back to a new file (maybe new file name).

Just do not have any ideas how to operate that for the binary file.

thanks for all the help (feedback)

usera

[BrewManNH]

_Crypt_EncryptFile

[usera]

_Crypt_EncryptFile

Thanks for your idea, but that is not what I am looking for.

I am looking for:

1. open that binary file (size unknown)

2. read all content in the memory (buffer)

3. read each byte then Add 01(Hex).

4. write back to a new file (maybe new file name).

Thanks

[guinness]

Open the help file and look at FileOpen, FileRead & FileWrite.

[BrewManNH]

That's not really encrypting the file very well, it wouldn't take much to decrypt that file once encrypted. But, if you want to reinvent the wheel, have at it.

[JohnOne]

usera, you have been a member here for over 5 years, and not once

have you posted a single line of code to help yourself.

I think it's about time you started.

[Kyan]

That's not really encrypting the file very well, it wouldn't take much to decrypt that file once encrypted. But, if you want to reinvent the wheel, have at it.

yup, with brute force, but if you know about crypt udf, can you explain if the derivedkey offers better protection than a plain password?

sorry if is a bit offtopic, i just wanna know

btw, I done 3days ago a function to crypt n' decrypt files, I think is what you're looking for

#include
Func _dec($iFile)
If FileExists($iFile) Then
Local $fOpen = FileOpen($iFile,16)
Local $fRead = FileRead($fOpen)
_Crypt_Startup()
Local $fDec = _Crypt_DecryptData($fRead, "yourPasswordGoesHere", $CALG_AES_256)
FileWrite(@ScriptDir & "decrypted.bin",$fDec)
_Crypt_Shutdown()
FileClose($fOpen)
;$Filename = StringRegExp($iFile,"(.*?)z",1)
EndIf
EndFunc

Func _enc($iFile)
_Crypt_Startup()
Local $fOpen = FileOpen($iFile,16)
Local $sData = FileRead($fOpen)
$crp = _Crypt_EncryptData($sData, "yourPasswordGoesHere", $CALG_AES_256)
FileWrite(@ScriptDir & "decrypted.bin",$crp)
FileClose($fOpen)
_Crypt_Shutdown()
EndFunc

PS: bbc of autoit code has some problems...

Edited September 14, 2012 by DiOgO

[guinness]

can you explain if the derivedkey offers better protection than a plain password?

_Crypt_EncryptData uses _Crypt_DeriveKey regardless of if you use a password or handle from previously calling_Crypt_DeriveKey. Look at the function for a better idea. Edited September 14, 2012 by guinness

[Kyan]

_Crypt_EncryptData uses _Crypt_DeriveKey regardless of if you use a password or handle from previously calling_Crypt_DeriveKey. Look at the function for a better idea.

so why who created the _Crypt_EncryptData function also created the _Crypt_DeriveKey? just to save some time in crypting a bunch of data?

in consolewrite, the derived key is like a 32bit string, but changes every time I execute the function, so may be easy do decrypt

Edited September 14, 2012 by DiOgO

[guinness]

It's because it's part of the Window's API >> CryptDeriveKey and someone may wish to retain the handle of _Crypt_DeriveKey, I for one just pass a password to the encrypt function.

[Kyan]

It's because it's part of the Window's API >> CryptDeriveKey and someone may wish to retain the handle of _Crypt_DeriveKey, I for one just pass a password to the encrypt function.

understood...

so no brute force blocking

[guinness]

I'm not following.

Edited September 14, 2012 by guinness

[Kyan]

I'm not following.

I thought that _Crypt_DeriveKey could give a bit more security against brute force atacks against encrypted data from crypt UDF, just it...

[guinness]

Oh OK. It's exactly the same security level, regardless of whether you use the handle or a password string.