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

Subject: Re: [Boost-users] boost.Iostream OpenSSL Filter
From: Will Mason (willchido_at_[hidden])
Date: 2012-08-08 14:29:43

Hello,

On Wed, Aug 8, 2012 at 1:10 PM, exocoder <exocoder_at_[hidden]> wrote:

> 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 :(
>

I think the OpenSSL EVP interface is the one you want:
http://www.openssl.org/docs/crypto/EVP_EncryptInit.html#

Cheers,
Will

> 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
>
>
>
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