From: Jarod Wilson Subject: Re: [PATCH v3] crypto: des3_ede: permit weak keys unless REQ_WEAK_KEY set Date: Sat, 06 Dec 2008 00:39:38 -0500 Message-ID: <493A101A.1080500@redhat.com> References: <200812041557.49601.jarod@redhat.com> <493942D9.6030807@redhat.com> <20081205152427.GA32475@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-crypto@vger.kernel.org, Neil Horman , linux-kernel@vger.kernel.org To: Herbert Xu Return-path: Received: from mx2.redhat.com ([66.187.237.31]:48402 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750809AbYLFFos (ORCPT ); Sat, 6 Dec 2008 00:44:48 -0500 In-Reply-To: <20081205152427.GA32475@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-ID: Jarod Wilson wrote: > While its a slightly insane to bypass the key1 == key2 || > key2 == key3 check in triple-des, since it reduces it to the > same strength as des, some folks do need to do this from time > to time for backwards compatibility with des. > > My own case is FIPS CAVS test vectors. Many triple-des test > vectors use a single key, replicated 3x. In order to get the > expected results, des3_ede_setkey() needs to honor the weak > key flag. v2: make CRYPTO_TFM_REQ_WEAK_KEY flag usage consistent w/rest of crypto subsystem, per comments from Herbert in Red Hat bugzilla #474394. v3: set more appropriate RES flag, also per Herbert. Signed-off-by: Jarod Wilson --- crypto/des_generic.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/crypto/des_generic.c b/crypto/des_generic.c index 5d0e458..5bd3ee3 100644 --- a/crypto/des_generic.c +++ b/crypto/des_generic.c @@ -868,9 +868,10 @@ static int des3_ede_setkey(struct crypto_tfm *tfm, const u8 *key, u32 *flags = &tfm->crt_flags; if (unlikely(!((K[0] ^ K[2]) | (K[1] ^ K[3])) || - !((K[2] ^ K[4]) | (K[3] ^ K[5])))) + !((K[2] ^ K[4]) | (K[3] ^ K[5]))) && + (*flags & CRYPTO_TFM_REQ_WEAK_KEY)) { - *flags |= CRYPTO_TFM_RES_BAD_KEY_SCHED; + *flags |= CRYPTO_TFM_RES_WEAK_KEY; return -EINVAL; } -- Jarod Wilson jarod@redhat.com