From patchwork Thu May 26 21:38:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Mueller X-Patchwork-Id: 9137449 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 096B46075C for ; Thu, 26 May 2016 21:38:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D048327B33 for ; Thu, 26 May 2016 21:38:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C522E282F7; Thu, 26 May 2016 21:38:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B6C15282F6 for ; Thu, 26 May 2016 21:38:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754788AbcEZViQ (ORCPT ); Thu, 26 May 2016 17:38:16 -0400 Received: from mail.eperm.de ([89.247.134.16]:34870 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754722AbcEZViQ (ORCPT ); Thu, 26 May 2016 17:38:16 -0400 Received: from positron.chronox.de (mail.eperm.de [89.247.134.16]) by mail.eperm.de (Postfix) with ESMTPA id BB4BA2A05D2; Thu, 26 May 2016 23:38:12 +0200 (CEST) From: Stephan Mueller To: David Howells Cc: Mat Martineau , keyrings@vger.kernel.org, linux-crypto@vger.kernel.org Subject: [PATCH v2] KEYS: Add placeholder KDF usage with DH Date: Thu, 26 May 2016 23:38:12 +0200 Message-ID: <4396788.BlSbYuWPli@positron.chronox.de> User-Agent: KMail/4.14.10 (Linux/4.4.9-300.fc23.x86_64; KDE/4.14.20; x86_64; ; ) In-Reply-To: <23038.1464293450@warthog.procyon.org.uk> References: <20160526165741.2634-1-mathew.j.martineau@linux.intel.com> <23038.1464293450@warthog.procyon.org.uk> MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Am Donnerstag, 26. Mai 2016, 21:10:50 schrieb David Howells: Hi David, Mat asked me to step in in case his patch needed an update. ---8<--- The values computed during Diffie-Hellman key exchange are often used in combination with key derivation functions to create cryptographic keys. Add a placeholder for a later implementation to configure a key derivation function that will transform the Diffie-Hellman result returned by the KEYCTL_DH_COMPUTE command. Signed-off-by: Mat Martineau Signed-off-by: Stephan Mueller --- Documentation/security/keys.txt | 5 ++++- security/keys/compat.c | 2 +- security/keys/dh.c | 8 +++++++- security/keys/internal.h | 5 +++-- security/keys/keyctl.c | 4 ++-- 5 files changed, 17 insertions(+), 7 deletions(-) diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt index 20d0571..3849814 100644 --- a/Documentation/security/keys.txt +++ b/Documentation/security/keys.txt @@ -826,7 +826,8 @@ The keyctl syscall functions are: (*) Compute a Diffie-Hellman shared secret or public key long keyctl(KEYCTL_DH_COMPUTE, struct keyctl_dh_params *params, - char *buffer, size_t buflen); + char *buffer, size_t buflen, + void *reserved); The params struct contains serial numbers for three keys: @@ -843,6 +844,8 @@ The keyctl syscall functions are: public key. If the base is the remote public key, the result is the shared secret. + The reserved argument must be set to NULL. + The buffer length must be at least the length of the prime, or zero. If the buffer length is nonzero, the length of the result is diff --git a/security/keys/compat.c b/security/keys/compat.c index c8783b3..36c80bf 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -134,7 +134,7 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, case KEYCTL_DH_COMPUTE: return keyctl_dh_compute(compat_ptr(arg2), compat_ptr(arg3), - arg4); + arg4, compat_ptr(arg5)); default: return -EOPNOTSUPP; diff --git a/security/keys/dh.c b/security/keys/dh.c index 880505a..531ed2e 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -78,7 +78,8 @@ error: } long keyctl_dh_compute(struct keyctl_dh_params __user *params, - char __user *buffer, size_t buflen) + char __user *buffer, size_t buflen, + void __user *reserved) { long ret; MPI base, private, prime, result; @@ -97,6 +98,11 @@ long keyctl_dh_compute(struct keyctl_dh_params __user *params, goto out; } + if (reserved) { + ret = -EINVAL; + goto out; + } + keylen = mpi_from_key(pcopy.prime, buflen, &prime); if (keylen < 0 || !prime) { /* buflen == 0 may be used to query the required buffer size, diff --git a/security/keys/internal.h b/security/keys/internal.h index 8ec7a52..a705a7d 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -260,10 +260,11 @@ static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring) #ifdef CONFIG_KEY_DH_OPERATIONS extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *, - size_t); + size_t, void __user *); #else static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params, - char __user *buffer, size_t buflen) + char __user *buffer, size_t buflen, + void __user *reserved) { return -EOPNOTSUPP; } diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 3b135a0..d580ad0 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1688,8 +1688,8 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, case KEYCTL_DH_COMPUTE: return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2, - (char __user *) arg3, - (size_t) arg4); + (char __user *) arg3, (size_t) arg4, + (void __user *) arg5); default: return -EOPNOTSUPP;