From patchwork Wed Jan 19 00:13:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12717011 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B55BCC433F5 for ; Wed, 19 Jan 2022 00:15:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350360AbiASAPA (ORCPT ); Tue, 18 Jan 2022 19:15:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346916AbiASAO6 (ORCPT ); Tue, 18 Jan 2022 19:14:58 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6027C061574; Tue, 18 Jan 2022 16:14:57 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 74DAE6149D; Wed, 19 Jan 2022 00:14:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA452C340E0; Wed, 19 Jan 2022 00:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642551296; bh=QtK9vZtfEtGk5fagKyEwFJSB/y/naDXkPKnDDSOiCPo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j2ZPqEz1n4HUm2aAfyLvThBNUnF8JoL0A18xK2EoX2tEFXbL3bgkCqHMi8FZAEg0d sCYQsVlQNc0bl7OsDACdDuV4hxjX724OZogqTf7oIMK+MMgxtrfSZWEnz88vWJD3vm eZTJ+K4l4KetygupUjVm4JM4z/Swv9y3PZD4ylgyPtm1MgZG1JOxn+RSzpiQQrAZtc ngFLCdhuKQA6K9tsvrg+fUxFxHt8mUtINumzCO9HIhJzVRuiQv6A+79SGrou0uhzFy D6Nh9P63lPzebUADuTAxZIzlDSz7PGQfkofoXRUUENvcogQnRuo5eqfEwvYReruQG4 tONbr/Mw/9MRg== From: Eric Biggers To: linux-crypto@vger.kernel.org, Herbert Xu Cc: keyrings@vger.kernel.org, Vitaly Chikunov , Denis Kenzior Subject: [PATCH v2 5/5] crypto: rsa-pkcs1pad - use clearer variable names Date: Tue, 18 Jan 2022 16:13:06 -0800 Message-Id: <20220119001306.85355-6-ebiggers@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220119001306.85355-1-ebiggers@kernel.org> References: <20220119001306.85355-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org From: Eric Biggers The new convention for akcipher_alg::verify makes it unclear which values are the lengths of the signature and digest. Add local variables to make it clearer what is going on. Also rename the digest_size variable in pkcs1pad_sign(), as it is actually the digest *info* size, not the digest size which is different. Signed-off-by: Eric Biggers --- crypto/rsa-pkcs1pad.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c index 9d804831c8b3f..3285e3af43e14 100644 --- a/crypto/rsa-pkcs1pad.c +++ b/crypto/rsa-pkcs1pad.c @@ -385,15 +385,15 @@ static int pkcs1pad_sign(struct akcipher_request *req) struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); const struct rsa_asn1_template *digest_info = ictx->digest_info; int err; - unsigned int ps_end, digest_size = 0; + unsigned int ps_end, digest_info_size = 0; if (!ctx->key_size) return -EINVAL; if (digest_info) - digest_size = digest_info->size; + digest_info_size = digest_info->size; - if (req->src_len + digest_size > ctx->key_size - 11) + if (req->src_len + digest_info_size > ctx->key_size - 11) return -EOVERFLOW; if (req->dst_len < ctx->key_size) { @@ -406,7 +406,7 @@ static int pkcs1pad_sign(struct akcipher_request *req) if (!req_ctx->in_buf) return -ENOMEM; - ps_end = ctx->key_size - digest_size - req->src_len - 2; + ps_end = ctx->key_size - digest_info_size - req->src_len - 2; req_ctx->in_buf[0] = 0x01; memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); req_ctx->in_buf[ps_end] = 0x00; @@ -441,6 +441,8 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) struct akcipher_instance *inst = akcipher_alg_instance(tfm); struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); const struct rsa_asn1_template *digest_info = ictx->digest_info; + const unsigned int sig_size = req->src_len; + const unsigned int digest_size = req->dst_len; unsigned int dst_len; unsigned int pos; u8 *out_buf; @@ -487,20 +489,19 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) err = 0; - if (req->dst_len != dst_len - pos) { + if (digest_size != dst_len - pos) { err = -EKEYREJECTED; req->dst_len = dst_len - pos; goto done; } /* Extract appended digest. */ sg_pcopy_to_buffer(req->src, - sg_nents_for_len(req->src, - req->src_len + req->dst_len), + sg_nents_for_len(req->src, sig_size + digest_size), req_ctx->out_buf + ctx->key_size, - req->dst_len, req->src_len); + digest_size, sig_size); /* Do the actual verification step. */ if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos, - req->dst_len) != 0) + digest_size) != 0) err = -EKEYREJECTED; done: kfree_sensitive(req_ctx->out_buf); @@ -536,14 +537,15 @@ static int pkcs1pad_verify(struct akcipher_request *req) struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); + const unsigned int sig_size = req->src_len; + const unsigned int digest_size = req->dst_len; int err; - if (WARN_ON(req->dst) || - WARN_ON(!req->dst_len) || - !ctx->key_size || req->src_len != ctx->key_size) + if (WARN_ON(req->dst) || WARN_ON(!digest_size) || + !ctx->key_size || sig_size != ctx->key_size) return -EINVAL; - req_ctx->out_buf = kmalloc(ctx->key_size + req->dst_len, GFP_KERNEL); + req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL); if (!req_ctx->out_buf) return -ENOMEM; @@ -556,8 +558,7 @@ static int pkcs1pad_verify(struct akcipher_request *req) /* Reuse input buffer, output to a new buffer */ akcipher_request_set_crypt(&req_ctx->child_req, req->src, - req_ctx->out_sg, req->src_len, - ctx->key_size); + req_ctx->out_sg, sig_size, ctx->key_size); err = crypto_akcipher_encrypt(&req_ctx->child_req); if (err != -EINPROGRESS && err != -EBUSY)