From patchwork Tue Mar 16 17:01:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12143113 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EDC55C43381 for ; Tue, 16 Mar 2021 17:03:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C35136511A for ; Tue, 16 Mar 2021 17:03:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237343AbhCPRCi (ORCPT ); Tue, 16 Mar 2021 13:02:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237599AbhCPRCN (ORCPT ); Tue, 16 Mar 2021 13:02:13 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22303C0613D7 for ; Tue, 16 Mar 2021 10:02:08 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lMD4c-0000Nt-4E; Tue, 16 Mar 2021 18:01:38 +0100 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lMD4Y-0000Vi-IM; Tue, 16 Mar 2021 18:01:34 +0100 From: Ahmad Fatoum To: James Bottomley , Jarkko Sakkinen , Mimi Zohar , David Howells Cc: kernel@pengutronix.de, Ahmad Fatoum , James Morris , "Serge E. Hallyn" , =?utf-8?q?Horia_Geant=C4=83?= , Aymen Sghaier , Herbert Xu , "David S. Miller" , Udit Agarwal , Jan Luebbe , David Gstir , Franck LENORMAND , Sumit Garg , keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v1 2/3] KEYS: trusted: implement fallback to kernel RNG Date: Tue, 16 Mar 2021 18:01:17 +0100 Message-Id: X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: keyrings@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org For cases a trusted key source already sources the kernel RNG, we can use get_random_bytes_wait to get the random data for key material. Make the get_random callback optional to allow sources to make use of this. Signed-off-by: Ahmad Fatoum --- To: James Bottomley To: Jarkko Sakkinen To: Mimi Zohar To: David Howells Cc: James Morris Cc: "Serge E. Hallyn" Cc: "Horia Geantă" Cc: Aymen Sghaier Cc: Herbert Xu Cc: "David S. Miller" Cc: Udit Agarwal Cc: Jan Luebbe Cc: David Gstir Cc: Franck LENORMAND Cc: Sumit Garg Cc: keyrings@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org --- include/keys/trusted-type.h | 2 +- security/keys/trusted-keys/trusted_core.c | 11 ++++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index d89fa2579ac0..4eb64548a74f 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -64,7 +64,7 @@ struct trusted_key_ops { /* Unseal a key. */ int (*unseal)(struct trusted_key_payload *p, char *datablob); - /* Get a randomized key. */ + /* Optional: Get a randomized key. */ int (*get_random)(unsigned char *key, size_t key_len); /* Exit key interface. */ diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index ec3a066a4b42..5f92323efedf 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -310,8 +311,14 @@ struct key_type key_type_trusted = { }; EXPORT_SYMBOL_GPL(key_type_trusted); +static int kernel_get_random(unsigned char *key, size_t key_len) +{ + return get_random_bytes_wait(key, key_len) ?: key_len; +} + static int __init init_trusted(void) { + int (*get_random)(unsigned char *key, size_t key_len); int i, ret = 0; for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) { @@ -320,6 +327,8 @@ static int __init init_trusted(void) strlen(trusted_key_sources[i].name))) continue; + get_random = trusted_key_sources[i].ops->get_random ?: kernel_get_random; + static_call_update(trusted_key_init, trusted_key_sources[i].ops->init); static_call_update(trusted_key_seal, @@ -327,7 +336,7 @@ static int __init init_trusted(void) static_call_update(trusted_key_unseal, trusted_key_sources[i].ops->unseal); static_call_update(trusted_key_get_random, - trusted_key_sources[i].ops->get_random); + get_random); static_call_update(trusted_key_exit, trusted_key_sources[i].ops->exit); migratable = trusted_key_sources[i].ops->migratable;