Re: [Boost-users] boost.Iostream OpenSSL Filter

Subject: Re: [Boost-users] boost.Iostream OpenSSL Filter
From: exocoder (exocoder_at_[hidden])
Date: 2012-08-08 14:10:19

Thank you for the info Neil,
I am looking at the example that you pointed to, need to get my head around the issues of
initialising/closing OpenSSL in the filter. It seems that every OpenSSL example uses a different
interface :(
Again Thank you for the advice.

On Mon, 2012-08-06 at 15:40 -0600, Neil Nelson wrote:
> exocoder,
> 
> Upon just reading the docs at
> 
> http://www.boost.org/doc/libs/1_50_0/libs/iostreams/doc/index.html
> 
> and particularly
> 
>      2.2.8. Multi-Character Filters
> 
> It looks like you could take the code from the following page
> 
> http://stackoverflow.com/questions/1007337/encrypting-and-decrypting-a-small-file-using-openssl
> 
> with the critical line being
> 
>      AES_cfb128_encrypt(indata, outdata, bytes_read, &key, ivec, &num, 
> AES_ENCRYPT);
> 
> that reads and writes to memory buffers. Two other aspects are: (1) 
> software using encryption is export restricted and you can research that 
> if needed for your application, (2) key management is likely the more 
> complicated part, and (3) use of initialization vectors (added random 
> bytes at the beginning of the input data).
> 
> Neil Nelson
> 
> > I am currently looking at using OpenSSL to write information to an
> > encrypted file on-the-fly so to speak. I have been researching my
> > options for doing this, and have come across the Boost.Iostream library,
> > which promises to be a very elegant solution (The documentation even
> > suggests that filters can be written to provide encryption/decryption
> > using OpenSSL).
> > It would seem that my best approach would be to use the BIO_f* interface
> > to encrypt a memory buffer, which could be written by overloading
> > write(). However the OpenSSL documentation is particularly sparse when
> > it comes to file/memory encryption and I would appreciate any advice on
> > how to do this.
> > Thank you in advance for any help proffered.
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users