Re: [Opensc-devel] Fwd: ECDH Engine

[Douglas E E. <dee...@gm...>]

I see you sent the same message to the openssl-dev list yesterday, but no one has responded yet.

OpenSC has a engine_pkcs11 that can do ECDSA, but no one has added ECDH yet. The main reason was that until OpenSSL-1.0.2 the routines in ECDSA_METHOD that needed to be replaced were not exposed, and 
it took years for the OpenSSL people to finally do something about this. They added ECDSA_METHOD_set_sign and ECDSA_METHOD_set_sign.

I am afraid it might be years until the ECDH has the extra routines need to work with an engine. To get the
ECDSA_METHOD changes into OpenSSL I had to get the engine working using the ecdsa/ec_locl.h header file
to show what was actually needed.


On 10/6/2015 12:37 PM, Alexander Gostrer wrote:
> Hi Doug,
>
> David suggested to contact you.
> We are writing an openssl ECDH engine. All private keys are in the hardware (including ephemeral keys). I found that the DH_METHOD has both (*generate_key) and (*compute_key) methods while the
> ECDH_METHOD has just the (*compute_key) method.

Your have the ephemeral keys in hardware? Won't that require a different ephemeral key for every active connection?

A key is a key, and there is a EC_KEY_generate_key defined in ec.h, that will work for ECDSA or ECDH.
But the ability to generate_key may also need to be exposed if you need to have the ephemeral keys created on the card.
I have not looked at what this would take.

>
> We would like (once the engine is completed) to use standard SSL_accept() etc calls. But the compute_key() returns shared secret based on previously generated public/private key pair and the public
> key is already sent to a peer). Is there a hook to replace the public key before it is sent out? Any ideas/plans about adding this hook into the code?

Not sure how to answer this.

>
> Thank you,
> Alex Gostrer.
>
>
>     On Tue, Oct 6, 2015 at 7:54 AM, David Woodhouse <dw...@in... <mailto:dw...@in...>> wrote:
>
>         On Tue, 2015-10-06 at 07:52 -0700, Alexander Gostrer wrote:
>          > Yeah, with ECDSA we have no problems. We thought about submitting a
>          > patch but the code is pretty complicated and we weren't sure that we
>          > completely understand it. Also we wanted to stick with the stable
>          > version.
>
>         You need to fix it in HEAD first. Then we can talk about backporting to
>         older versions.
>
>          >  Do you have Doug's email? Don't want to spam other people.
>
>         Probably best to use the opensc mailing list.
>         ope...@li... <mailto:ope...@li...>
>
>         --
>         dwmw2
>
>
>
>
>
> ------------------------------------------------------------------------------
>
>
>
> _______________________________________________
> Opensc-devel mailing list
> Ope...@li...
> https://lists.sourceforge.net/lists/listinfo/opensc-devel
>

-- 

  Douglas E. Engert  <DEE...@gm...>