From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCF79C43381 for ; Thu, 28 Feb 2019 18:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F5EC218D0 for ; Thu, 28 Feb 2019 18:39:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733113AbfB1Sj1 (ORCPT ); Thu, 28 Feb 2019 13:39:27 -0500 Received: from vmicros1.altlinux.org ([194.107.17.57]:58248 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732879AbfB1Sj0 (ORCPT ); Thu, 28 Feb 2019 13:39:26 -0500 Received: from imap.altlinux.org (imap.altlinux.org [194.107.17.38]) by vmicros1.altlinux.org (Postfix) with ESMTP id 2E47172CA65; Thu, 28 Feb 2019 21:39:24 +0300 (MSK) Received: from altlinux.org (sole.flsd.net [185.75.180.6]) by imap.altlinux.org (Postfix) with ESMTPSA id 0FC2F4A4AE7; Thu, 28 Feb 2019 21:39:24 +0300 (MSK) Date: Thu, 28 Feb 2019 21:39:23 +0300 From: Vitaly Chikunov To: David Howells Cc: Herbert Xu , Mimi Zohar , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 04/10] crypto: akcipher - new verify API for public key algorithms Message-ID: <20190228183923.5klzwli5zmeew54j@altlinux.org> Mail-Followup-To: David Howells , Herbert Xu , Mimi Zohar , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190224060828.2527-5-vt@altlinux.org> <20190224060828.2527-1-vt@altlinux.org> <14843.1551377934@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <14843.1551377934@warthog.procyon.org.uk> User-Agent: NeoMutt/20171215-106-ac61c7 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org David, On Thu, Feb 28, 2019 at 06:18:54PM +0000, David Howells wrote: > Vitaly Chikunov wrote: > > > + digest = kmemdup(sig->digest, sig->digest_size, GFP_KERNEL); > > + if (!digest) > > You shouldn't need to copy the digest. It's being passed in to the crypto > algorithm, not extracted out. That's how Herbert suggested to do it. Quoting FYI: | On Fri, Feb 01, 2019 at 02:26:55PM +0800, Herbert Xu wrote: | > On Fri, Jan 25, 2019 at 09:01:16PM +0300, Vitaly Chikunov wrote: | > > | > > @@ -781,36 +780,17 @@ static int tpm_key_verify_signature(const struct key *key, | > > if (!req) | > > goto error_free_tfm; | > > | > > - ret = -ENOMEM; | > > - outlen = crypto_akcipher_maxsize(tfm); | > > - output = kmalloc(outlen, GFP_KERNEL); | > > - if (!output) | > > - goto error_free_req; | > > - | > > - sg_init_one(&sig_sg, sig->s, sig->s_size); | > > - sg_init_one(&digest_sg, output, outlen); | > > - akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size, | > > - outlen); | > > + sg_init_table(&src_sg, 2); | > > + sg_set_buf(&src_sg[0], sig->s, sig->s_size); | > > + sg_set_buf(&src_sg[1], sig->digest, sig->digest_size); | > > + akcipher_request_set_crypt(req, &src_sg, NULL, sig->s_size, | > > + sig->digest_size); | > | > It's not clear that sig->digest is guaranteed to be kmalloc memory. | > In any case, it's best not to mix unrelated changes in a single | > patch. So please keep the kmalloc on output and then copy | > sig->digest into it and put output into the SG list. > > + if (memcmp(c, outbuf_enc, c_size)) { > > Please use == 0 and != 0 with memcmp() and strcmp(). Their return values are > kind of inverted in sense if you treat them as boolean. OK. Thanks!