Re: reply: reply: A new realization of ecc-sm2

[Niels Möller]

"zhongxuan (A)"  writes:

> Yes, I've tried to make a fork in
> https://git.lysator.liu.se/nettle/nettle/-/forks/new but failed, it
> just reports ' An error occurred while forking the project. Please try
> again. '.

Sorry, I don't really know how to troubleshoot. Maybe you can try if it
works better on the mirror repo at https://gitlab.com/gnutls/nettle?

I've had a new look at your latest patch. I'm not at all familiar with
sm2, and I'm hoping I don't have to fully understand all details, but I
am a bit confused.

I think one important part of your patch is about adding support for
Weierstrass curves with a different constant than a = -3.

And then I look at the spec at
https://datatracker.ietf.org/doc/html/draft-shen-sm2-ecdsa to see how
the curve really is defined. It looks like that document gives several
examples of curves, including one named "Fp-256", but the one that it
looks like you are defining, in eccdata.c, is the one defined in
Appendix D "Recommended parameters".

So my first question: Is "sm2" an appropriate name for a single curve,
or is there some more specific name for the curve in Appendix D that you
use?

Second question, when I look at that curve, it is defined like this:

:A elliptic curve on a prime field of 256 bits is recommended:
: 
: 
:y^2 = x^3 + ax + b
: 
: 
: p=FFFE       
: a=FFFE       FFFC
: b=28E9FA9E 9D9F5E34 4D5A9E4B CF6509A7 F39789F5 15AB8F92 DDBCBD41 4D940E93
: n=FFFE    7203DF6B 21C6052B 53BBF409 39D54123
: Gx=32C4AE2C 1F198119 5F990446 6A39C994 8FE30BBF F2660BE1 715A4589 334C74C7
: Gy=BC3736A2 F4F6779C 59BDCEE3 6B692153 D0A9877C C62A4740 02DF32E5 2139F0A0

But for this parameters, we have a = p - 3 = -3 (mod p), like for all
other Weierstrass curves currently supported by Nettle! Which is good
news, since then the same point addition functions can be used, but it
also means that maybe you have done some work that isn't really needed?

Regards,
/Niels


-- 
Niels Möller. PGP key CB4962D070D77D7FCB8BA36271D8F1FF368C6677.
Internet email is subject to wholesale government surveillance.
___
nettle-bugs mailing list -- nettle-bugs@lists.lysator.liu.se
To unsubscribe send an email to nettle-bugs-le...@lists.lysator.liu.se

reply: reply: A new realization of ecc-sm2

[zhongxuan (A)]

> "zhongxuan (A)"  writes:

>> Where should I commit my patch? The access request to fork in Nettle / 
>> nettle * GitLab (liu.se) was 
>> denied.

> Hi, I think you asked for "developer access" in the Nettle repo, which would 
> allow you to push any changes you like to the repository. You can't have 
> that, but unfortunately, I couldn't add any explanatory message when pushing 
> the deny button in gitlab.

> The usual way to contribute code in gitlab (as well as on github), is that 
> you make your own "fork" of the repository, where you have full permissions. 
> You commit your changes to a branch in that fork, and then create a merge 
> request asking for changes to be merged into the original repo.

Yes, I've tried to make a fork in 
https://git.lysator.liu.se/nettle/nettle/-/forks/new but failed, it just 
reports ' An error occurred while forking the project. Please try again. '.
I replied a long email but tragically didn’t attach my patch.
Here I attach my new patch of ecc-sm2.
Besides, could you help me figure out what's wrong with my fork? I preferred to 
commit in fork mode, too.

> See
> https://docs.gitlab.com/ee/user/project/repository/forking_workflow.html
> on how to create a fork from the gitlab ui.

> When you work with git locally, you can have both your own "fork" repo and 
> the original repo as git "remotes".
  
> And if gitlab doesn't work out for you, you could also send the updated patch 
> to this list.

> Best regards,
> /Niels

> --
> Niels Möller. PGP key CB4962D070D77D7FCB8BA36271D8F1FF368C6677.
> Internet email is subject to wholesale government surveillance.
___
nettle-bugs mailing list -- nettle-bugs@lists.lysator.liu.se
To unsubscribe send an email to nettle-bugs-le...@lists.lysator.liu.se