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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C7BBCC6778C for ; Sun, 1 Jul 2018 17:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8273725719 for ; Sun, 1 Jul 2018 17:49:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8273725719 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030810AbeGARtS (ORCPT ); Sun, 1 Jul 2018 13:49:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35338 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030732AbeGAQdK (ORCPT ); Sun, 1 Jul 2018 12:33:10 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 5CA5249B; Sun, 1 Jul 2018 16:33:09 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej S. Szmigiero" , James Morris Subject: [PATCH 4.14 089/157] X.509: unpack RSA signatureValue field from BIT STRING Date: Sun, 1 Jul 2018 18:22:41 +0200 Message-Id: <20180701160857.013501298@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180701160852.287307684@linuxfoundation.org> References: <20180701160852.287307684@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej S. Szmigiero commit b65c32ec5a942ab3ada93a048089a938918aba7f upstream. The signatureValue field of a X.509 certificate is encoded as a BIT STRING. For RSA signatures this BIT STRING is of so-called primitive subtype, which contains a u8 prefix indicating a count of unused bits in the encoding. We have to strip this prefix from signature data, just as we already do for key data in x509_extract_key_data() function. This wasn't noticed earlier because this prefix byte is zero for RSA key sizes divisible by 8. Since BIT STRING is a big-endian encoding adding zero prefixes has no bearing on its value. The signature length, however was incorrect, which is a problem for RSA implementations that need it to be exactly correct (like AMD CCP). Signed-off-by: Maciej S. Szmigiero Fixes: c26fd69fa009 ("X.509: Add a crypto key parser for binary (DER) X.509 certificates") Cc: stable@vger.kernel.org Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -249,6 +249,15 @@ int x509_note_signature(void *context, s return -EINVAL; } + if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0) { + /* Discard the BIT STRING metadata */ + if (vlen < 1 || *(const u8 *)value != 0) + return -EBADMSG; + + value++; + vlen--; + } + ctx->cert->raw_sig = value; ctx->cert->raw_sig_size = vlen; return 0;