On Wed, 2019-11-13 at 11:11 -0500, Jason Qian wrote:
> Hi Tomas,
>
> Using DH_compute_key_padded() seems fixed the problem.
>
> I have one more question regarding a similar issue but this time is
> about AES key generation.
>
> I think the problem is related to RAND_seed or RAND_bytes (someone
> also mentioned on another thread).
>
> RAND_seed(seed, ::strlen(seed));
> RAND_bytes(buf, keySize / 8);
>
I do not understand what is the problem you have. But nevertheless -
you should not need to call RAND_seed() unless you are running the code
on some very special platform where no method of automatical seeding of
the OpenSSL RNG is available.
Your RAND_bytes() call should be fine to produce an AES key of bit
length keySize.
>
>
>
>
>
> On Tue, Nov 12, 2019 at 10:50 AM Jason Qian <jqian@xxxxxxxxx> wrote:
> > Thanks Tomas,
> >
> > I will try that.
> >
> > On Tue, Nov 12, 2019 at 3:14 AM Tomas Mraz <tmraz@xxxxxxxxxx>
> > wrote:
> > > On Mon, 2019-11-04 at 17:34 -0500, Jason Qian via openssl-users
> > > wrote:
> > > > Hi
> > > >
> > > > We have an application that does the Diffie Hellman key
> > > exchange
> > > > (OpenSSL/1.1.0f).
> > > > It works fine, but under heavy loaded conditions, sometimes
> > > an
> > > > invalide secret been generated and other side couldn't decrypt
> > > the
> > > > data (the secret seems offset by one).
> > > >
> > > > The client side is c++ and the server side is java.
> > > >
> > > > DH_compute_key(secretKey, bnY, m_DH);
> > > >
> > > > Someone in the openssl group also talks about a similar
> > > issue, but
> > > > not sure if have a solution.
> > >
> > > Could it be a padding issue? I.E. use DH_compute_key_padded()
> > > instead.
> > >
--
Tomáš Mráz
No matter how far down the wrong road you've gone, turn back.
Turkish proverb
[You'll know whether the road is wrong if you carefully listen to your
conscience.]
