From patchwork Tue Jun 22 12:37:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12337227 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=-16.7 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=unavailable 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 E1AA9C48BDF for ; Tue, 22 Jun 2021 12:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE7C761374 for ; Tue, 22 Jun 2021 12:39:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231592AbhFVMlO (ORCPT ); Tue, 22 Jun 2021 08:41:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231200AbhFVMlE (ORCPT ); Tue, 22 Jun 2021 08:41:04 -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 16FF6C0613A2 for ; Tue, 22 Jun 2021 05:38:47 -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 1lvffV-0001dk-Sp; Tue, 22 Jun 2021 14:38:17 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lvffS-0002Py-KA; Tue, 22 Jun 2021 14:38:14 +0200 From: Ahmad Fatoum To: James Bottomley , Jarkko Sakkinen , Mimi Zohar , David Howells Cc: kernel@pengutronix.de, Ahmad Fatoum , James Morris , Eric Biggers , "Serge E. Hallyn" , =?utf-8?q?Horia_Geant=C4=83?= , Aymen Sghaier , Udit Agarwal , Jan Luebbe , David Gstir , Richard Weinberger , 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 v2 1/6] KEYS: trusted: allow use of TEE as backend without TCG_TPM support Date: Tue, 22 Jun 2021 14:37:47 +0200 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: linux-security-module@vger.kernel.org Precedence: bulk List-ID: With recent rework, trusted keys are no longer limited to TPM as trust source. The Kconfig symbol is unchanged however leading to a few issues: - TCG_TPM is required, even if only TEE is to be used - Enabling TCG_TPM, but excluding it from available trusted sources is not possible - TEE=m && TRUSTED_KEYS=y will lead to TEE support being silently dropped, which is not the best user experience Remedy these issues by introducing two new Kconfig symbols: TRUSTED_KEYS_TPM and TRUSTED_KEYS_TEE with the appropriate dependencies. Signed-off-by: Ahmad Fatoum --- To: James Bottomley To: Jarkko Sakkinen To: Mimi Zohar To: David Howells Cc: James Morris Cc: Eric Biggers Cc: "Serge E. Hallyn" Cc: "Horia Geantă" Cc: Aymen Sghaier Cc: Udit Agarwal Cc: Jan Luebbe Cc: David Gstir Cc: Richard Weinberger 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 --- security/keys/Kconfig | 14 ++++++------- security/keys/trusted-keys/Kconfig | 25 ++++++++++++++++++++++++- security/keys/trusted-keys/Makefile | 8 +++++--- security/keys/trusted-keys/trusted_core.c | 4 ++-- 4 files changed, 39 insertions(+), 12 deletions(-) create mode 100644 security/keys/trusted-keys/Kconfig diff --git a/security/keys/Kconfig b/security/keys/Kconfig index 64b81abd087e..6fdb953b319f 100644 --- a/security/keys/Kconfig +++ b/security/keys/Kconfig @@ -70,23 +70,23 @@ config BIG_KEYS config TRUSTED_KEYS tristate "TRUSTED KEYS" - depends on KEYS && TCG_TPM + depends on KEYS select CRYPTO select CRYPTO_HMAC select CRYPTO_SHA1 select CRYPTO_HASH_INFO - select ASN1_ENCODER - select OID_REGISTRY - select ASN1 help This option provides support for creating, sealing, and unsealing keys in the kernel. Trusted keys are random number symmetric keys, - generated and RSA-sealed by the TPM. The TPM only unseals the keys, - if the boot PCRs and other criteria match. Userspace will only ever - see encrypted blobs. + generated and sealed by a trust source selected at kernel boot-time. + Userspace will only ever see encrypted blobs. If you are unsure as to whether this is required, answer N. +if TRUSTED_KEYS +source "security/keys/trusted-keys/Kconfig" +endif + config ENCRYPTED_KEYS tristate "ENCRYPTED KEYS" depends on KEYS diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig new file mode 100644 index 000000000000..24af4aaceebf --- /dev/null +++ b/security/keys/trusted-keys/Kconfig @@ -0,0 +1,25 @@ +config TRUSTED_KEYS_TPM + bool "TPM-based trusted keys" + depends on TCG_TPM >= TRUSTED_KEYS + default y + select ASN1_ENCODER + select OID_REGISTRY + select ASN1 + help + Enable use of the Trusted Platform Module (TPM) as trusted key + backend. Trusted keys are are random number symmetric keys, + which will be generated and RSA-sealed by the TPM. + The TPM only unseals the keys, if the boot PCRs and other + criteria match. + +config TRUSTED_KEYS_TEE + bool "TEE-based trusted keys" + depends on TEE >= TRUSTED_KEYS + default y + help + Enable use of the Trusted Execution Environment (TEE) as trusted + key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE +comment "No trust source selected!" +endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index feb8b6c3cc79..96fc6c377398 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -5,10 +5,12 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o trusted-y += trusted_core.o -trusted-y += trusted_tpm1.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o $(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h -trusted-y += trusted_tpm2.o -trusted-y += tpm2key.asn1.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o +trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o + +trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o trusted-$(CONFIG_TEE) += trusted_tee.o diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index d5c891d8d353..8cab69e5d0da 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0); MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); static const struct trusted_key_source trusted_key_sources[] = { -#if defined(CONFIG_TCG_TPM) +#if defined(CONFIG_TRUSTED_KEYS_TPM) { "tpm", &trusted_key_tpm_ops }, #endif -#if defined(CONFIG_TEE) +#if defined(CONFIG_TRUSTED_KEYS_TEE) { "tee", &trusted_key_tee_ops }, #endif };