From: Corentin LABBE Subject: Re: [PATCH 4/4] crypto: qce: If total text size is zero, return pre-computed digest Date: Tue, 30 Aug 2016 18:02:42 +0200 Message-ID: <7f71762d-f570-e4d4-723c-fc2dc821ab6e@gmail.com> References: <20160830155353.19500-1-voker57@gmail.com> <20160830155353.19500-5-voker57@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, andy.gross@linaro.org, david.brown@linaro.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org To: Iaroslav Gridin , herbert@gondor.apana.org.au Return-path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:33984 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755847AbcH3QCq (ORCPT ); Tue, 30 Aug 2016 12:02:46 -0400 In-Reply-To: <20160830155353.19500-5-voker57@gmail.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 30/08/2016 17:53, Iaroslav Gridin wrote: > From: Voker57 > > If total data amount to hash is zero, we cannot submit it to QCE, > since it locks up on zero-sized updates. So, return pre-computed > SHA256/SHA1 hash. > Signed-off-by: Iaroslav Gridin > --- > drivers/crypto/qce/sha.c | 27 ++++++++++++++++++++++++--- > 1 file changed, 24 insertions(+), 3 deletions(-) > > diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c > index f199f28..c627b5d 100644 > --- a/drivers/crypto/qce/sha.c > +++ b/drivers/crypto/qce/sha.c > @@ -80,6 +80,7 @@ static int qce_ahash_async_req_handle(struct crypto_async_request *async_req) > struct qce_sha_ctx *ctx = crypto_tfm_ctx(async_req->tfm); > struct qce_alg_template *tmpl = to_ahash_tmpl(async_req->tfm); > struct qce_device *qce = tmpl->qce; > + unsigned int digestsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(req)); > unsigned long flags = rctx->flags; > int ret; > > @@ -91,6 +92,29 @@ static int qce_ahash_async_req_handle(struct crypto_async_request *async_req) > rctx->authklen = AES_KEYSIZE_128; > } > > + if (!req->nbytes) { > + /* Only way that can happen is if total size of digest is zero > + * So since QCE gets stuck on zero-sized texts, we return > + * pre-calculated hash > + */ > + if (digestsize == SHA1_DIGEST_SIZE) { > + memcpy(rctx->digest, > + "\xda\x39\xa3\xee\x5e\x6b\x4b\x0d\x32\x55\xbf\xef\x95\x60\x18\x90\xaf\xd8\x07\x09", > + SHA1_DIGEST_SIZE); > + } else if (digestsize == SHA256_DIGEST_SIZE) { > + memcpy(rctx->digest, > + "\xe3\xb0\xc4\x42\x98\xfc\x1c\x14\x9a\xfb\xf4\xc8\x99\x6f\xb9\x24\x27\xae\x41\xe4\x64\x9b\x93\x4c\xa4\x95\x99\x1b\x78\x52\xb8\x55", > + SHA256_DIGEST_SIZE); Hello You could use sha1_zero_message_hash/sha256_zero_message_hash declared in crypto/sha.h Regards