[v2,6/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

Message ID	39e6d65ca5d2a0a35fb71d6c1f85add8ee489a19.1624364386.git-series.a.fatoum@pengutronix.de (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> From: Ahmad Fatoum <a.fatoum@pengutronix.de> To: Jonathan Corbet <corbet@lwn.net>, David Howells <dhowells@redhat.com>, Jarkko Sakkinen <jarkko@kernel.org>, James Bottomley <jejb@linux.ibm.com>, Mimi Zohar <zohar@linux.ibm.com> Cc: kernel@pengutronix.de, Ahmad Fatoum <a.fatoum@pengutronix.de>, James Morris <jmorris@namei.org>, "Serge E. Hallyn" <serge@hallyn.com>, =?utf-8?q?Horia_Geant=C4=83?= <horia.geanta@nxp.com>, Aymen Sghaier <aymen.sghaier@nxp.com>, Herbert Xu <herbert@gondor.apana.org.au>, "David S. Miller" <davem@davemloft.net>, Udit Agarwal <udit.agarwal@nxp.com>, Eric Biggers <ebiggers@kernel.org>, Jan Luebbe <j.luebbe@pengutronix.de>, David Gstir <david@sigma-star.at>, Richard Weinberger <richard@nod.at>, Franck LENORMAND <franck.lenormand@nxp.com>, Sumit Garg <sumit.garg@linaro.org>, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 6/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys Date: Tue, 22 Jun 2021 14:37:52 +0200 Message-Id: <39e6d65ca5d2a0a35fb71d6c1f85add8ee489a19.1624364386.git-series.a.fatoum@pengutronix.de> In-Reply-To: <cover.1dfbb73645d917b3c76d01290804a3410bd9932e.1624364386.git-series.a.fatoum@pengutronix.de> References: <cover.1dfbb73645d917b3c76d01290804a3410bd9932e.1624364386.git-series.a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	KEYS: trusted: Introduce support for NXP CAAM-based trusted keys \| expand [v2,0/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys [v2,1/6] KEYS: trusted: allow use of TEE as backend without TCG_TPM support [v2,3/6] KEYS: trusted: allow users to use kernel RNG for key material [v2,4/6] KEYS: trusted: allow trust sources to use kernel RNG for key material [v2,5/6] crypto: caam - add in-kernel interface for blob generator [v2,6/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys [v2,2/6] KEYS: trusted: Allow import from existing key material for development

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f8bdc898c354..4a95369c2bc7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5639,6 +5639,7 @@ sources: - "tpm" - "tee" + - "caam" If not specified then it defaults to iterating through the trust source list starting with TPM and assigns the first trust source as a backend which is initialized diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index 3fb5562ee937..3461746b1fbd 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -35,6 +35,13 @@ safe. Rooted to Hardware Unique Key (HUK) which is generally burnt in on-chip fuses and is accessible to TEE only. + (3) CAAM (Cryptographic Acceleration and Assurance Module: IP on NXP SoCs) + + When High Assurance Boot (HAB) is enabled and the CAAM is in secure + mode, trust is rooted to the OTPMK, a never-disclosed 256-bit key + randomly generated and fused into each SoC at manufacturing time. + Otherwise, a common fixed test key is used instead. + * Execution isolation (1) TPM @@ -46,6 +53,10 @@ safe. Customizable set of operations running in isolated execution environment verified via Secure/Trusted boot process. + (3) CAAM + + Fixed set of operations running in isolated execution environment. + * Optional binding to platform integrity state (1) TPM @@ -63,6 +74,11 @@ safe. Relies on Secure/Trusted boot process for platform integrity. It can be extended with TEE based measured boot process. + (3) CAAM + + Relies on the High Assurance Boot (HAB) mechanism of NXP SoCs + for platform integrity. + * Interfaces and APIs (1) TPM @@ -74,10 +90,13 @@ safe. TEEs have well-documented, standardized client interface and APIs. For more details refer to ``Documentation/staging/tee.rst``. + (3) CAAM + + Interface is specific to silicon vendor. * Threat model - The strength and appropriateness of a particular TPM or TEE for a given + The strength and appropriateness of a particular trust source for a given purpose must be assessed when using them to protect security-relevant data. @@ -104,8 +123,14 @@ selected trust source: from platform specific hardware RNG or a software based Fortuna CSPRNG which can be seeded via multiple entropy sources. + * CAAM: Kernel RNG + + The normal kernel random number generator is used. To seed it from the + CAAM HWRNG, enable CRYPTO_DEV_FSL_CAAM_RNG_API and ensure the device + can be probed. + Optionally, users may specify ``trusted.kernel_rng=1`` on the kernel -command-line to override the used RNG with the kernel's random number pool. +command-line to force use of the kernel's random number pool. Encrypted Keys -------------- @@ -192,6 +217,19 @@ Usage:: specific to TEE device implementation. The key length for new keys is always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). +Trusted Keys usage: CAAM +------------------------ + +Usage:: + + keyctl add trusted name "new keylen" ring + keyctl add trusted name "load hex_blob" ring + keyctl print keyid + +"keyctl print" returns an ASCII hex copy of the sealed key, which is in format +specific to CAAM device implementation. The key length for new keys is always +in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits). + Trusted Keys: import plain-text key for development --------------------------------------------------- diff --git a/include/keys/trusted_caam.h b/include/keys/trusted_caam.h new file mode 100644 index 000000000000..2fba0996b0b0 --- /dev/null +++ b/include/keys/trusted_caam.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de> + */ + +#ifndef __CAAM_TRUSTED_KEY_H +#define __CAAM_TRUSTED_KEY_H + +extern struct trusted_key_ops caam_trusted_key_ops; + +#endif diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig index 8bd69b252bf9..641bed8923ec 100644 --- a/security/keys/trusted-keys/Kconfig +++ b/security/keys/trusted-keys/Kconfig @@ -20,7 +20,16 @@ config TRUSTED_KEYS_TEE Enable use of the Trusted Execution Environment (TEE) as trusted key backend. -if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE +config TRUSTED_KEYS_CAAM + bool "CAAM-based trusted keys" + depends on CRYPTO_DEV_FSL_CAAM_JR >= TRUSTED_KEYS + select CRYPTO_DEV_FSL_CAAM_BLOB_GEN + default y + help + Enable use of NXP's Cryptographic Accelerator and Assurance Module + (CAAM) as trusted key backend. + +if !TRUSTED_KEYS_TPM && !TRUSTED_KEYS_TEE && !TRUSTED_KEYS_CAAM comment "No trust source selected!" endif diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile index 96fc6c377398..5788bc07a2ab 100644 --- a/security/keys/trusted-keys/Makefile +++ b/security/keys/trusted-keys/Makefile @@ -14,3 +14,5 @@ trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o trusted-$(CONFIG_TEE) += trusted_tee.o + +trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o diff --git a/security/keys/trusted-keys/trusted_caam.c b/security/keys/trusted-keys/trusted_caam.c new file mode 100644 index 000000000000..01adfd18adda --- /dev/null +++ b/security/keys/trusted-keys/trusted_caam.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de> + */ + +#include <keys/trusted_caam.h> +#include <keys/trusted-type.h> +#include <linux/build_bug.h> +#include <linux/key-type.h> +#include <soc/fsl/caam-blob.h> + +static struct caam_blob_priv *blobifier; + +#define KEYMOD "kernel:trusted" + +static_assert(MAX_KEY_SIZE + CAAM_BLOB_OVERHEAD <= CAAM_BLOB_MAX_LEN); +static_assert(MAX_BLOB_SIZE <= CAAM_BLOB_MAX_LEN); + +static int trusted_caam_seal(struct trusted_key_payload *p, char *datablob) +{ + int length = p->key_len + CAAM_BLOB_OVERHEAD; + int ret; + + ret = caam_encap_blob(blobifier, KEYMOD, p->key, p->blob, length); + if (ret) + return ret; + + p->blob_len = length; + return 0; +} + +static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob) +{ + int length = p->blob_len; + int ret; + + ret = caam_decap_blob(blobifier, KEYMOD, p->blob, p->key, length); + if (ret) + return ret; + + p->key_len = length - CAAM_BLOB_OVERHEAD; + return 0; +} + +static int trusted_caam_init(void) +{ + int ret; + + blobifier = caam_blob_gen_init(); + if (IS_ERR(blobifier)) { + pr_err("Job Ring Device allocation for transform failed\n"); + return PTR_ERR(blobifier); + } + + ret = register_key_type(&key_type_trusted); + if (ret) + caam_blob_gen_exit(blobifier); + + return ret; +} + +static void trusted_caam_exit(void) +{ + unregister_key_type(&key_type_trusted); + caam_blob_gen_exit(blobifier); +} + +struct trusted_key_ops caam_trusted_key_ops = { + .migratable = 0, /* non-migratable */ + .init = trusted_caam_init, + .seal = trusted_caam_seal, + .unseal = trusted_caam_unseal, + .exit = trusted_caam_exit, +}; diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c index 8d829e6866ca..21997a5debde 100644 --- a/security/keys/trusted-keys/trusted_core.c +++ b/security/keys/trusted-keys/trusted_core.c @@ -9,6 +9,7 @@ #include <keys/user-type.h> #include <keys/trusted-type.h> #include <keys/trusted_tee.h> +#include <keys/trusted_caam.h> #include <keys/trusted_tpm.h> #include <linux/capability.h> #include <linux/err.h> @@ -29,7 +30,7 @@ MODULE_PARM_DESC(kernel_rng, "Generate key material from kernel RNG"); static char *trusted_key_source; module_param_named(source, trusted_key_source, charp, 0); -MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)"); +MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee or caam)"); static const struct trusted_key_source trusted_key_sources[] = { #if defined(CONFIG_TRUSTED_KEYS_TPM) @@ -38,6 +39,9 @@ static const struct trusted_key_source trusted_key_sources[] = { #if defined(CONFIG_TRUSTED_KEYS_TEE) { "tee", &trusted_key_tee_ops }, #endif +#if defined(CONFIG_TRUSTED_KEYS_CAAM) + { "caam", &caam_trusted_key_ops }, +#endif }; DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);

[v2,6/6] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

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