From: Juston Davies <justondavies@...>
Date: 2009-08-26T02:21:15+09:00
Subject: Re: Working with openssl and files

Well that did it. Wasn't the write, but the read. Thanks a bunch!

On Aug 25, 11:16 am, Aaron Patterson <aa...@tenderlovemaking.com>
wrote:
> On Wed, Aug 26, 2009 at 01:33:02AM +0900, Juston Davies wrote:
> > Let me start out by saying all I do is in the name of science, I only
> > say this because what Im about to ask seems unreasonable. I'm trying
> > to:
>
> > 1.) Take an existing ruby script
> > 2.) Encrypt it
> > 3.) Store the encrypted copy in another file
> > 4.) Reopen that file
> > 5.) Decrypt the contents
> > 6.) eval the contents
>
> > I have some code so far, here is what it looks like:
> > -----------------------------------------------------------------------------------------------------------------------------------
> > require 'openssl'
>
> > def encrypt(data, key, iv, cipher_type)
> >   aes = OpenSSL::Cipher::Cipher.new(cipher_type)
> >   aes.encrypt
> >   aes.key = key
> >   aes.iv = iv if iv != nil
> >   aes.update(data) + aes.final
> > end
>
> > def decrypt(encrypted_data, key, iv, cipher_type)
> >   aes = OpenSSL::Cipher::Cipher.new(cipher_type)
> >   aes.decrypt
> >   aes.key = key
> >   aes.iv = iv if iv != nil
> >   aes.update(encrypted_data) + aes.final
> > end
>
> > @key = "borgeddd"*4
> > @salt = nil
> > @algorithm = "AES-256-ECB"
>
> > file = File.new("./Ruby_Script.rb")
>
> > encrypted_file = File.open("borged", 'w')
>
> You probably need to open the file in binary write mode:
>
>   encrypted_file = File.open("borged", 'wb')
>
>
>
> > encrypted_output = encrypt(file.read, @key, @salt, @algorithm)
> > encrypted_file.write(encrypted_output)
>
> > encrypted_file.close
>
> > file = File.open("borged")
> > decrypted_output = decrypt(file.read, @key, @salt, @algorithm) #works
> > if I just use the string encrypted_output
> > puts decrypted_output
>
> > eval decrypted_output
> > -----------------------------------------------------------------------------------------------------------------------------------
>
> > The code works if I just encrypt and decrypt strings, but when I write
> > to a file it appears its losing data. After encrypting the data and
> > looking at the length of the string its roughly about 1,000
> > characters, however, after I write to a file and close/reopen it the
> > new content is only about 300 characters long. That could be a bad
> > measurement, but it seems to me like Im losing something in the
> > translation. When I actually run this code as it is I get:
>
> > "C:/Workspace/Hob-nobbery/init.rb:16:in `final': wrong final block
> > length (OpenSSL::CipherError)"
> > "     from C:/Workspace/Hob-nobbery/init.rb:16:in `decrypt'"
>
> > Any ideas?
>
> Try opening the file in binary write mode as I've written above.  I
> think that will work out the problems.
>
> --
> Aaron Pattersonhttp://tenderlovemaking.com/