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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 DE977C4363A for ; Mon, 26 Oct 2020 18:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8779720874 for ; Mon, 26 Oct 2020 18:26:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603736795; bh=gybTqJ0jxhz6SPBPfV2ny6/w0HsDcFeLANRpB3SrjT4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Issgmeivf3L5VtRgV5NgjFoCTR881bryIaC2ge7jsOik6q0AAvdJntE4ygXWK61Cl zz9XEhHEZr/cFSOv0HzwctNXsEu4uMP11++MkMzW//ozh/r3/2+QSHNuh3WShUQIav 50/2Uh1lGg0GeDpL1R6smimB93yECMVZ/u/RHvok= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1789712AbgJZS0c (ORCPT ); Mon, 26 Oct 2020 14:26:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:34858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1789657AbgJZS0b (ORCPT ); Mon, 26 Oct 2020 14:26:31 -0400 Received: from sol.localdomain (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 80DAE20874; Mon, 26 Oct 2020 18:26:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603736790; bh=gybTqJ0jxhz6SPBPfV2ny6/w0HsDcFeLANRpB3SrjT4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1803MW6Ms9+aCqQkPsbvfnbuiXZPpwcohNI+9CJZHMm7ySsAEDdNj22URn9yEW8+w skoPbxs8WnAHiNomj0SKd5p7oL17WFlEF3a0iZAZwiK5HQ5ZyWJn8Wz1kzjWsUa+Z0 pflDe0VL8WWHOLnSfnYAEg931OZtGQqGqaU2AoOQ= Date: Mon, 26 Oct 2020 11:26:28 -0700 From: Eric Biggers To: Gilad Ben-Yossef Cc: Herbert Xu , "David S. Miller" , Song Liu , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Ofir Drang , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: [PATCH 1/4] crypto: add eboiv as a crypto API template Message-ID: <20201026182628.GI858@sol.localdomain> References: <20201026130450.6947-1-gilad@benyossef.com> <20201026130450.6947-2-gilad@benyossef.com> <20201026182448.GH858@sol.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201026182448.GH858@sol.localdomain> Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On Mon, Oct 26, 2020 at 11:24:50AM -0700, Eric Biggers wrote: > > +static int eboiv_create(struct crypto_template *tmpl, struct rtattr **tb) > > +{ > > + struct crypto_attr_type *algt; > > + const char *inner_cipher_name; > > + struct skcipher_instance *skcipher_inst = NULL; > > + struct crypto_instance *inst; > > + struct crypto_alg *base, *block_base; > > + struct eboiv_instance_ctx *ictx; > > + struct skcipher_alg *skcipher_alg = NULL; > > + int ivsize; > > + u32 mask; > > + int err; > > + > > + algt = crypto_get_attr_type(tb); > > + if (IS_ERR(algt)) > > + return PTR_ERR(algt); > > Need to check that the algorithm is being instantiated as skcipher. > crypto_check_attr_type() should be used. > > > + > > + inner_cipher_name = crypto_attr_alg_name(tb[1]); > > + if (IS_ERR(inner_cipher_name)) > > + return PTR_ERR(inner_cipher_name); > > The result of crypto_attr_alg_name() can be passed directly to > crypto_grab_skcipher(). > > > + mask = crypto_algt_inherited_mask(algt); > > + > > + skcipher_inst = kzalloc(sizeof(*skcipher_inst) + sizeof(*ictx), GFP_KERNEL); > > + if (!skcipher_inst) > > + return -ENOMEM; > > + > > + inst = skcipher_crypto_instance(skcipher_inst); > > + base = &skcipher_inst->alg.base; > > + ictx = crypto_instance_ctx(inst); > > + > > + /* Symmetric cipher, e.g., "cbc(aes)" */ > > + err = crypto_grab_skcipher(&ictx->skcipher_spawn, inst, inner_cipher_name, 0, mask); > > + if (err) > > + goto out_free_inst; > > + > > + skcipher_alg = crypto_spawn_skcipher_alg(&ictx->skcipher_spawn); > > + block_base = &skcipher_alg->base; > > + ivsize = crypto_skcipher_alg_ivsize(skcipher_alg); > > + > > + if (ivsize != block_base->cra_blocksize) > > + goto out_drop_skcipher; > > Shouldn't it be verified that the underlying algorithm is actually cbc? > > > + skcipher_inst->alg.chunksize = crypto_skcipher_alg_chunksize(skcipher_alg); > > + skcipher_inst->alg.walksize = crypto_skcipher_alg_walksize(skcipher_alg); > > Setting these isn't necessary. > > > + > > + skcipher_inst->free = eboiv_skcipher_free_instance; > > + > > + err = skcipher_register_instance(tmpl, skcipher_inst); > > + > > + if (err) > > + goto out_drop_skcipher; > > + > > + return 0; > > + > > +out_drop_skcipher: > > + crypto_drop_skcipher(&ictx->skcipher_spawn); > > +out_free_inst: > > + kfree(skcipher_inst); > > + return err; > > +} > > eboiv_skcipher_free_instance() can be called on the error path. Here's the version of eboiv_create() I recommend (untested): static int eboiv_create(struct crypto_template *tmpl, struct rtattr **tb) { struct skcipher_instance *inst; struct eboiv_instance_ctx *ictx; struct skcipher_alg *alg; u32 mask; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask); if (err) return err; inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); if (!inst) return -ENOMEM; ictx = skcipher_instance_ctx(inst); err = crypto_grab_skcipher(&ictx->skcipher_spawn, skcipher_crypto_instance(inst), crypto_attr_alg_name(tb[1]), 0, mask); if (err) goto err_free_inst; alg = crypto_spawn_skcipher_alg(&ictx->skcipher_spawn); err = -EINVAL; if (strncmp(alg->base.cra_name, "cbc(", 4) || crypto_skcipher_alg_ivsize(alg) != alg->base.cra_blocksize) goto err_free_inst; err = -ENAMETOOLONG; if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, "eboiv(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME) goto err_free_inst; if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "eboiv(%s)", alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) goto err_free_inst; inst->alg.base.cra_blocksize = alg->base.cra_blocksize; inst->alg.base.cra_ctxsize = sizeof(struct eboiv_tfm_ctx); inst->alg.base.cra_alignmask = alg->base.cra_alignmask; inst->alg.base.cra_priority = alg->base.cra_priority; inst->alg.setkey = eboiv_skcipher_setkey; inst->alg.encrypt = eboiv_skcipher_encrypt; inst->alg.decrypt = eboiv_skcipher_decrypt; inst->alg.init = eboiv_skcipher_init_tfm; inst->alg.exit = eboiv_skcipher_exit_tfm; inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg); inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg); inst->alg.ivsize = crypto_skcipher_alg_ivsize(alg); inst->free = eboiv_skcipher_free_instance; err = skcipher_register_instance(tmpl, inst); if (err) { err_free_inst: eboiv_skcipher_free_instance(inst); } return err; }