On Monday, August 26, 2019 at 4:09:47 PM UTC-4, Jeffrey Walton wrote:
>
> On Mon, Aug 26, 2019 at 2:30 PM Philippe Antoine
> <[email protected]> wrote:
> >
> > My same is Philippe Antoine.
> > I have been doing differential fuzzing about elliptic curve cryptography
> with different libraries including cryptopp.
> >
> > On August the 6th, oss-fuzz found the first regression after about one
> year.
> > I think this is dut to commit
> https://github.com/weidai11/cryptopp/commit/c9ef9420e762b91cc06463d349cf06e04c749b9d
>
> >
> > My output is the following
> >
> point=04202020202020ffffff2020202020200020ffffffff20202020ff20ff20ff200104c8423eb699c3ace2e623855cb9238cb43971464f4b6686765c46ed4ce035dc
>
>
> >
> bignum=000000000000000000000000000000000000000000000000000000000000000a
> >
> mbedlts:045de6bae41907dbe3f0aa32b272add6b92fb2b79fdc49af35fb844be1c4c629e899295109c41cfe76a9c06c23d95b2d4be3b6f61a476acf1a67a0d848abba89e1
>
>
> >
> libecc:045de6bae41907dbe3f0aa32b272add6b92fb2b79fdc49af35fb844be1c4c629e899295109c41cfe76a9c06c23d95b2d4be3b6f61a476acf1a67a0d848abba89e1
>
>
> >
> libecc:045de6bae41907dbe3f0aa32b272add6b92fb2b79fdc49af35fb844be1c4c629e899295109c41cfe76a9c06c23d95b2d4be3b6f61a476acf1a67a0d848abba89e1
>
>
> >
> openssl:045de6bae41907dbe3f0aa32b272add6b92fb2b79fdc49af35fb844be1c4c629e899295109c41cfe76a9c06c23d95b2d4be3b6f61a476acf1a67a0d848abba89e1
>
>
> >
> gcrypt:045de6bae41907dbe3f0aa32b272add6b92fb2b79fdc49af35fb844be1c4c629e899295109c41cfe76a9c06c23d95b2d4be3b6f61a476acf1a67a0d848abba89e1
>
>
> >
> cryptopp:0407f16bad8b16f5441f1a15f8e7eca364d97bb3a3c09b320bb9807ee26857b66f882ba526e55ebbf22342ae5a0186ed0ca1db8870fd001c63ae36dc72ee15f6e7
>
>
> >
> > That means when I multiply by 10 the point on the curve brainpoolP256r1
> >
> > x = 202020202020ffffff2020202020200020ffffffff20202020ff20ff20ff2001
> >
> > y = 04c8423eb699c3ace2e623855cb9238cb43971464f4b6686765c46ed4ce035dc
> >
> > I get a different result than all the other libraries
> >
> > I will look into it a bit more, but I already wanted to let you know
> this...
>
> Thanks Philippe.
>
> Yeah, that's not good. Does your test include a fresh check-out and
> build of the Crypto++ library?
>
Ugh, I can duplicate it with:
Integer
x("0x202020202020ffffff2020202020200020ffffffff20202020ff20ff20ff2001");
Integer
y("0x04c8423eb699c3ace2e623855cb9238cb43971464f4b6686765c46ed4ce035dc");
Integer
s("0x000000000000000000000000000000000000000000000000000000000000000a");
GroupParameters params(ASN1::brainpoolP256r1());
ECP::Element p(x, y);
ECP::Element t = params.GetCurve().ScalarMultiply(p, s);
std::cout << std::hex << t.x << std::endl;
std::cout << std::hex << t.y << std::endl;
--
You received this message because you are subscribed to "Crypto++ Users". More
information about Crypto++ and this group is available at
http://www.cryptopp.com and
http://groups.google.com/forum/#!forum/cryptopp-users.
---
You received this message because you are subscribed to the Google Groups
"Crypto++ Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/cryptopp-users/4f35713d-0ece-42f9-9961-70eba21dfd26%40googlegroups.com.
