From: Stefan Hellermann Subject: Re: [PATCH] [crypto] XTS: use proper alignment v2 Date: Wed, 05 Mar 2008 23:48:01 +0100 Message-ID: <47CF2321.6020100@the2masters.de> References: <20080302135135.GC16659@Chamillionaire.breakpoint.cc> <958c4032ba3b28931dea586d0338bf1ec1594659.1204465942.git.sebastian@breakpoint.cc> <20080305111602.GB27552@gondor.apana.org.au> <20080305114652.GA18070@Chamillionaire.breakpoint.cc> <20080305115203.GA28021@gondor.apana.org.au> <20080305120153.GA18425@Chamillionaire.breakpoint.cc> <47CEA7F5.2080700@the2masters.de> <20080305163753.GA20787@Chamillionaire.breakpoint.cc> <20080305221746.GA32072@Chamillionaire.breakpoint.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Herbert Xu , linux-crypto@vger.kernel.org To: Sebastian Siewior Return-path: Received: from smtp10.unit.tiscali.de ([213.205.33.46]:55469 "EHLO smtp10.unit.tiscali.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755787AbYCEWsy (ORCPT ); Wed, 5 Mar 2008 17:48:54 -0500 In-Reply-To: <20080305221746.GA32072@Chamillionaire.breakpoint.cc> Sender: linux-crypto-owner@vger.kernel.org List-ID: > The XTS blockmode uses a copy of the IV which is saved on the stack > and may or may not be properly aligned. If it is not, it will break > hardware cipher like the geode or padlock. > This patch encrypts the IV in place so we don't have to worry about > alignment. > > Signed-off-by: Sebastian Siewior > --- > Herbert, I tried the small patch thing :) > It passed tcrypt on my geode, dunno about dm-crypt & friends. > Stefan if you could test it with dm-crypt than we have a small fix :) Yes, this passwd my tests, too! Nice :) Tested-by: Stefan Hellermann crypto/xts.c | 13 ++++++------- > 1 files changed, 6 insertions(+), 7 deletions(-) > > diff --git a/crypto/xts.c b/crypto/xts.c > index 8eb08bf..d87b0f3 100644 > --- a/crypto/xts.c > +++ b/crypto/xts.c > @@ -77,16 +77,16 @@ static int setkey(struct crypto_tfm *parent, const u8 *key, > } > > struct sinfo { > - be128 t; > + be128 *t; > struct crypto_tfm *tfm; > void (*fn)(struct crypto_tfm *, u8 *, const u8 *); > }; > > static inline void xts_round(struct sinfo *s, void *dst, const void *src) > { > - be128_xor(dst, &s->t, src); /* PP <- T xor P */ > + be128_xor(dst, s->t, src); /* PP <- T xor P */ > s->fn(s->tfm, dst, dst); /* CC <- E(Key1,PP) */ > - be128_xor(dst, dst, &s->t); /* C <- T xor CC */ > + be128_xor(dst, dst, s->t); /* C <- T xor CC */ > } > > static int crypt(struct blkcipher_desc *d, > @@ -101,7 +101,6 @@ static int crypt(struct blkcipher_desc *d, > .tfm = crypto_cipher_tfm(ctx->child), > .fn = fn > }; > - be128 *iv; > u8 *wsrc; > u8 *wdst; > > @@ -109,20 +108,20 @@ static int crypt(struct blkcipher_desc *d, > if (!w->nbytes) > return err; > > + s.t = (be128 *)w->iv; > avail = w->nbytes; > > wsrc = w->src.virt.addr; > wdst = w->dst.virt.addr; > > /* calculate first value of T */ > - iv = (be128 *)w->iv; > - tw(crypto_cipher_tfm(ctx->tweak), (void *)&s.t, w->iv); > + tw(crypto_cipher_tfm(ctx->tweak), w->iv, w->iv); > > goto first; > > for (;;) { > do { > - gf128mul_x_ble(&s.t, &s.t); > + gf128mul_x_ble(s.t, s.t); > > first: > xts_round(&s, wdst, wsrc);