From: Ulf Hansson Subject: Re: [PATCH 1/8] crypto: hash: add zero length message hash for shax and md5 Date: Fri, 16 Oct 2015 13:26:08 +0200 Message-ID: References: <1444668826-6531-1-git-send-email-clabbe.montjoie@gmail.com> <1444668826-6531-2-git-send-email-clabbe.montjoie@gmail.com> <20151014100802.GA15884@gondor.apana.org.au> <20151015094204.GA6305@Red> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Herbert Xu , LABBE Corentin , "David S. Miller" , thomas.lendacky@amd.com, Geert Uytterhoeven , Wolfram Sang , Kees Cook , Maxime Ripard , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org To: LABBE Corentin Return-path: Received: from mail-wi0-f176.google.com ([209.85.212.176]:37942 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753640AbbJPL0K (ORCPT ); Fri, 16 Oct 2015 07:26:10 -0400 Received: by wicll6 with SMTP id ll6so5971841wic.1 for ; Fri, 16 Oct 2015 04:26:08 -0700 (PDT) In-Reply-To: <20151015094204.GA6305@Red> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 15 October 2015 at 11:42, LABBE Corentin wrote: > On Wed, Oct 14, 2015 at 06:08:02PM +0800, Herbert Xu wrote: >> On Mon, Oct 12, 2015 at 06:53:39PM +0200, LABBE Corentin wrote: >> > Some crypto drivers cannot process empty data message and return a >> > precalculated hash for md5/sha1/sha224/sha256. >> > >> > This patch add thoses precalculated hash in include/crypto. >> > >> > Signed-off-by: LABBE Corentin >> > --- >> > include/crypto/md5.h | 5 +++++ >> > include/crypto/sha.h | 20 ++++++++++++++++++++ >> > 2 files changed, 25 insertions(+) >> > >> > diff --git a/include/crypto/md5.h b/include/crypto/md5.h >> > index 146af82..6496ee0 100644 >> > --- a/include/crypto/md5.h >> > +++ b/include/crypto/md5.h >> > @@ -13,6 +13,11 @@ >> > #define MD5_H2 0x98badcfeUL >> > #define MD5_H3 0x10325476UL >> > >> > +static const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = { >> > + 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04, >> > + 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e, >> > +}; >> > + >> >> This potentially creates this structure in every file that includes >> md5.h. How about putting it into md5_generic and exporting it? >> > > md5_generic does not exists, do you mean md5.c ? > I have made some try with EXPORT_SYMBOL() but without success. > Do you have any example of how to do that ? > In the header file: extern const u8 md5_zero_message_hash[MD5_DIGEST_SIZE]; In the c-file: const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = { 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04, 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e, }; EXPORT_SYMBOL(md5_zero_message_hash); Kind regards Uffe