public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "Stephan Müller" <smueller@chronox.de>
To: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Nicolai Stange <nstange@suse.de>
Cc: Hannes Reinecke <hare@suse.de>, Torsten Duwe <duwe@suse.de>,
	Zaibo Xu <xuzaibo@huawei.com>,
	Giovanni Cabiddu <giovanni.cabiddu@intel.com>,
	David Howells <dhowells@redhat.com>,
	Jarkko Sakkinen <jarkko@kernel.org>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	qat-linux@intel.com, keyrings@vger.kernel.org,
	Nicolai Stange <nstange@suse.de>
Subject: Re: [PATCH 16/18] crypto: dh - calculate Q from P for the full public key verification
Date: Sun, 05 Dec 2021 07:07:11 +0100	[thread overview]
Message-ID: <4182894.UPlyArG6xL@positron.chronox.de> (raw)
In-Reply-To: <20211201004858.19831-17-nstange@suse.de>

Am Mittwoch, 1. Dezember 2021, 01:48:56 CET schrieb Nicolai Stange:

Hi Nicolai,

> As the ->q in struct dh_ctx gets never set anywhere, the code
> in dh_is_pubkey_valid() for doing the full public key validation in
> accordance to SP800-56Arev3 is effectively dead.
> 
> However, for safe-prime groups, Q = (P - 1)/2 by definition and this
> enables dh_is_pubkey_valid() to calculate Q on the fly for these groups.
> Implement this.
> 
> With this change, the last code accessing struct dh_ctx's ->q is now gone.
> Remove this member from struct dh_ctx.

Isn't it expensive to always calculate Q for a-priori known values? Why not 
add Q to the safe-prime definitions and do not do this operation here?

If you need Q for all of those safe-primes, you may get them from [1] and 
following lines.

[1] https://github.com/smuellerDD/acvpparser/blob/master/parser/
safeprimes.h#L346

Ciao
Stephan



  parent reply	other threads:[~2021-12-05  6:07 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-01  0:48 [PATCH 00/18] crypto: dh - infrastructure for NVM in-band auth and FIPS conformance Nicolai Stange
2021-12-01  0:48 ` [PATCH 01/18] crypto: dh - remove struct dh's ->q member Nicolai Stange
2021-12-01  7:11   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 02/18] crypto: dh - constify struct dh's pointer members Nicolai Stange
2021-12-01  7:13   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 03/18] crypto: dh - optimize domain parameter serialization for well-known groups Nicolai Stange
2021-12-01  7:17   ` Hannes Reinecke
2021-12-09  9:08     ` Nicolai Stange
2021-12-01  0:48 ` [PATCH 04/18] crypto: dh - introduce RFC 7919 safe-prime groups Nicolai Stange
2021-12-01  7:23   ` Hannes Reinecke
2021-12-09  9:10     ` Nicolai Stange
2021-12-01  0:48 ` [PATCH 05/18] crypto: testmgr - add DH RFC 7919 ffdhe2048 test vector Nicolai Stange
2021-12-01  7:24   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 06/18] crypto: dh - introduce RFC 3526 safe-prime groups Nicolai Stange
2021-12-01  7:24   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 07/18] crypto: testmgr - add DH RFC 3526 modp2048 test vector Nicolai Stange
2021-12-01  7:25   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 08/18] crypto: testmgr - run only subset of DH vectors based on config Nicolai Stange
2021-12-01  7:28   ` Hannes Reinecke
2021-12-09  9:18     ` Nicolai Stange
2021-12-01  0:48 ` [PATCH 09/18] crypto: dh - implement private key generation primitive Nicolai Stange
2021-12-01  7:28   ` Hannes Reinecke
2021-12-05  5:52   ` Stephan Müller
2021-12-08  6:20     ` Nicolai Stange
2021-12-08  7:16       ` Stephan Mueller
2021-12-01  0:48 ` [PATCH 10/18] crypto: dh - introduce support for ephemeral key generation to dh-generic Nicolai Stange
2021-12-01  7:29   ` Hannes Reinecke
2021-12-05  6:11   ` Stephan Müller
2021-12-08  6:32     ` Nicolai Stange
2021-12-01  0:48 ` [PATCH 11/18] crypto: dh - introduce support for ephemeral key generation to hpre driver Nicolai Stange
2021-12-01  7:30   ` Hannes Reinecke
2021-12-05  6:11   ` Stephan Müller
2021-12-01  0:48 ` [PATCH 12/18] crypto: dh - introduce support for ephemeral key generation to qat driver Nicolai Stange
2021-12-01  7:30   ` Hannes Reinecke
2021-12-05  6:11   ` Stephan Müller
2021-12-01  0:48 ` [PATCH 13/18] crypto: testmgr - add DH test vectors for key generation Nicolai Stange
2021-12-01  7:31   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 14/18] lib/mpi: export mpi_rshift Nicolai Stange
2021-12-01  7:32   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 15/18] crypto: dh - store group id in dh-generic's dh_ctx Nicolai Stange
2021-12-01  7:32   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 16/18] crypto: dh - calculate Q from P for the full public key verification Nicolai Stange
2021-12-01  7:33   ` Hannes Reinecke
2021-12-05  6:07   ` Stephan Müller [this message]
2021-12-08  6:41     ` Nicolai Stange
2021-12-01  0:48 ` [PATCH 17/18] crypto: dh - try to match domain parameters to a known safe-prime group Nicolai Stange
2021-12-01  7:34   ` Hannes Reinecke
2021-12-01  0:48 ` [PATCH 18/18] crypto: dh - accept only approved safe-prime groups in FIPS mode Nicolai Stange
2021-12-01  7:34   ` Hannes Reinecke
2021-12-09  9:26     ` Nicolai Stange

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4182894.UPlyArG6xL@positron.chronox.de \
    --to=smueller@chronox.de \
    --cc=davem@davemloft.net \
    --cc=dhowells@redhat.com \
    --cc=duwe@suse.de \
    --cc=giovanni.cabiddu@intel.com \
    --cc=hare@suse.de \
    --cc=herbert@gondor.apana.org.au \
    --cc=jarkko@kernel.org \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nstange@suse.de \
    --cc=qat-linux@intel.com \
    --cc=xuzaibo@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox